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%%
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%% This is file `/usr2/distrib/latex209/nfss/array.sty' generated
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%% on <1991/11/22> with the docstrip utility (v1.1k).
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%%
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%% The original source files were:
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%%
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%% /usr2/users/latex3/source/array/array.doc
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%%
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%% Copyright (C) 1989,1990,1991 by Frank Mittelbach, Rainer Schoepf.
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%% All rights reserved.
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%%
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%% This file is part of the NFSS (New Font Selection Scheme) package.
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%%
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%% IMPORTANT NOTICE:
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%%
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%% You are not allowed to change this file. You may however copy this file
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%% to a file with a different name and then change the copy if you obey
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||||||
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%% the restrictions on file changes described in readme.mz.
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%%
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%% You are allowed to distribute this file under the condition that it is
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%% distributed together with all files mentioned in readme.mz3. If you
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%% receive only some of these files from someone, complain!
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||||||
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%%
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||||||
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%% You are NOT ALLOWED to distribute this file alone. You are NOT ALLOWED
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||||||
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%% to take money for the distribution or use of either this file or a
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%% changed version, except for a nominal charge for copying etc.
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%%
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||||||
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%% For error reports in case of UNCHANGED versions see readme files.
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%%
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||||||
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%% Please do not request updates from us directly. Distribution is done
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%% through Mail-Servers and TeX organizations.
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%%
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\def\fileversion{v2.0e}
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\def\filedate{91/02/07}
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\def\docdate {90/08/20}
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%% \CheckSum{681}
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%% \CharacterTable
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%% {Upper-case \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
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%% Lower-case \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
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%% Digits \0\1\2\3\4\5\6\7\8\9
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%% Exclamation \! Double quote \" Hash (number) \#
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%% Dollar \$ Percent \% Ampersand \&
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%% Acute accent \' Left paren \( Right paren \)
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%% Asterisk \* Plus \+ Comma \,
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%% Minus \- Point \. Solidus \/
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%% Colon \: Semicolon \; Less than \<
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%% Equals \= Greater than \> Question mark \?
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%% Commercial at \@ Left bracket \[ Backslash \\
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%% Right bracket \] Circumflex \^ Underscore \_
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%% Grave accent \` Left brace \{ Vertical bar \|
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%% Right brace \} Tilde \~}
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%%
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\@ifundefined{d@llar}{}{\endinput}
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\typeout{Style-Option: `array' \fileversion
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\space\space <\filedate> (F.M.)}
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\typeout{English documentation dated \space <\docdate> (F.M.)}
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\def\@addtopreamble#1{\xdef\@preamble{\@preamble #1}}
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\def\@testpach#1{\@chclass
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\ifnum \@lastchclass=6 \@ne \@chnum \@ne \else
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\ifnum \@lastchclass=7 5 \else
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\ifnum \@lastchclass=8 \tw@ \else
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\ifnum \@lastchclass=9 \thr@@
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\else \z@
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\ifnum \@lastchclass = 10 \else
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\@chnum
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\if #1c\z@ \else
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\if #1l\@ne \else
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\if #1r\tw@ \else
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\z@ \@chclass
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\if#1|\@ne \else
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\if #1!6 \else
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\if #1@7 \else
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\if #1<8 \else
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\if #1>9 \else
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10
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\@chnum
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\if #1m\thr@@\else
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\if #1p4 \else
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\if #1b5 \else
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\z@ \@chclass \z@ \@preamerr \z@ \fi \fi \fi \fi
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\fi \fi \fi \fi \fi \fi \fi \fi \fi \fi \fi \fi}
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\def\@xexpast#1*#2#3#4\@@{%
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\@tempcnta #2
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\toks@={#1}\@temptokena={#3}%
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\let\the@toksz\relax \let\the@toks\relax
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\def\@tempa{\the@toksz}%
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\ifnum\@tempcnta >0 \@whilenum\@tempcnta >0\do
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{\edef\@tempa{\@tempa\the@toks}\advance \@tempcnta \m@ne}%
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\let \@tempb \@xexpast \else
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\let \@tempb \@xexnoop \fi
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\def\the@toksz{\the\toks@}\def\the@toks{\the\@temptokena}%
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\edef\@tempa{\@tempa}%
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\expandafter \@tempb \@tempa #4\@@}
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\def\prepnext@tok{\advance \count@ \@ne
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\toks\count@={}}
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\def\save@decl{\toks\count@ \expandafter{\@nextchar}}
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\def\insert@column{%
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\the@toks \the \@tempcnta
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{\ignorespaces \@sharp \unskip}%
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\the@toks \the \count@ \relax}
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\newdimen\col@sep
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\def\@acol{\@addtopreamble{\hskip\col@sep}}
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\def\@mkpream#1{\gdef\@preamble{}\@lastchclass 4 \@firstamptrue
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\let\@sharp\relax \let\@startpbox\relax \let\@endpbox\relax
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\@xexpast #1*0x\@@
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\count@\m@ne
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\let\the@toks\relax
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\prepnext@tok
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\expandafter \@tfor \expandafter \@nextchar
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\expandafter :\expandafter =\@tempa \do
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{\@testpach\@nextchar
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\ifcase \@chclass \@classz \or \@classi \or \@classii
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\or \save@decl \or \or \@classv \or \@classvi
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\or \@classvii \or \@classviii \or \@classix
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\or \@classx \fi
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\@lastchclass\@chclass}%
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\ifcase\@lastchclass
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\@acol \or
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\or
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\@acol \or
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\@preamerr \thr@@ \or
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\@preamerr \tw@ \@addtopreamble\@sharp \or
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\or
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\else \@preamerr \@ne \fi
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\def\the@toks{\the\toks}}
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\def\@classx{%
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\ifcase \@lastchclass
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\@acolampacol \or
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\@addamp \@acol \or
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\@acolampacol \or
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\or
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\@acol \@firstampfalse \or
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\@addamp
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\fi}
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\def\@classz{\@classx
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\@tempcnta \count@
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\prepnext@tok
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\@addtopreamble{\ifcase \@chnum
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\hfil
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\d@llar
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\insert@column
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\d@llar \hfil \or
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\d@llar \insert@column \d@llar \hfil \or
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\hfil\kern\z@ \d@llar \insert@column \d@llar \or
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$\vcenter
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\@startpbox{\@nextchar}\insert@column \@endpbox $\or
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\vtop \@startpbox{\@nextchar}\insert@column \@endpbox \or
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\vbox \@startpbox{\@nextchar}\insert@column \@endpbox
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\fi}\prepnext@tok}
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\def\@classix{\ifnum \@lastchclass = \thr@@
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\@preamerr \thr@@ \fi
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\@classx}
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\def\@classviii{\ifnum \@lastchclass >\z@
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\@preamerr 4\@chclass 6 \@classvi \fi}
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\def\@arrayrule{\@addtopreamble \vline}
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\def\@classvii{\ifnum \@lastchclass = \thr@@
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\@preamerr \thr@@ \fi}
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\def\@classvi{\ifcase \@lastchclass
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\@acol \or
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\@addtopreamble{\hskip \doublerulesep}\or
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\@acol \or
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\@classvii
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\fi}
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\def\@classii{\advance \count@ \m@ne
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\save@decl\prepnext@tok}
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\def\@classv{\save@decl
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\@addtopreamble{\d@llar\the@toks\the\count@\relax\d@llar}%
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\prepnext@tok}
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\def\@classi{\@classvi
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\ifcase \@chnum \@arrayrule \or
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\@classv \fi}
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\def\@startpbox#1{\bgroup
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\hsize #1 \@arrayparboxrestore
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\vrule \@height \ht\@arstrutbox \@width \z@}
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\def\@endpbox{\vrule \@width \z@ \@depth \dp \@arstrutbox \egroup}
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\def\@array[#1]#2{%
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\@tempdima \ht \strutbox
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\advance \@tempdima by\extrarowheight
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\setbox \@arstrutbox \hbox{\vrule
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\@height \arraystretch \@tempdima
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||||||
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\@depth \arraystretch \dp \strutbox
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\@width \z@}%
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\begingroup
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\@mkpream{#2}%
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\xdef\@preamble{\ialign \@halignto
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\bgroup \@arstrut \@preamble
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\tabskip \z@ \cr}%
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\endgroup
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\if #1t\vtop \else \if#1b\vbox \else \vcenter \fi \fi
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\bgroup
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\let \@sharp ##\let \protect \relax
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\lineskip \z@
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\baselineskip \z@
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||||||
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\m@th
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\let\\ \@arraycr \let\par\@empty \@preamble}
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\newdimen \extrarowheight
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\extrarowheight=0pt
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\def\@arstrut{\unhcopy\@arstrutbox}
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\def\@arraycr{{\ifnum 0=`}\fi
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\@ifstar \@xarraycr \@xarraycr}
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\def\@xarraycr{\@ifnextchar [%
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\@argarraycr {\ifnum 0=`{\fi}\cr}}
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\def\@argarraycr[#1]{\ifnum0=`{\fi}\ifdim #1>\z@
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\@xargarraycr{#1}\else \@yargarraycr{#1}\fi}
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\def\@xargarraycr#1{\unskip
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\@tempdima #1\advance\@tempdima \dp\@arstrutbox
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\vrule \@depth\@tempdima \@width\z@ \cr}
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\def\@yargarraycr#1{\cr\noalign{\vskip #1}}
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\def\multicolumn#1#2#3{%
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\multispan{#1}\begingroup
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\def\@addamp{\if@firstamp \@firstampfalse \else
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\@preamerr 5\fi}%
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\@mkpream{#2}\@addtopreamble\@empty
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\endgroup
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\def\@sharp{#3}%
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\@arstrut \@preamble \ignorespaces}
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\def\array{\col@sep\arraycolsep
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\def\d@llar{$}\gdef\@halignto{}%
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\@tabarray}
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\def\@tabarray{\@ifnextchar[{\@array}{\@array[c]}}
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\def\tabular{\gdef\@halignto{}\@tabular}
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\expandafter\def\csname tabular*\endcsname#1{%
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\gdef\@halignto{to#1}\@tabular}
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\def\@tabular{%
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\leavevmode
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\hbox \bgroup $\col@sep\tabcolsep \let\d@llar\@empty
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\@tabarray}
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\def\endarray{\crcr \egroup \egroup \gdef\@preamble{}}
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\def\endtabular{\endarray $\egroup}
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\expandafter\let\csname endtabular*\endcsname=\endtabular
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\let\@ampacol=\relax \let\@expast=\relax
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\let\@arrayclassiv=\relax \let\@arrayclassz=\relax
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\let\@tabclassiv=\relax \let\@tabclassz=\relax
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\let\@arrayacol=\relax \let\@tabacol=\relax
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\let\@tabularcr=\relax \let\@@endpbox=\relax
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\let\@argtabularcr=\relax \let\@xtabularcr=\relax
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\def\@preamerr#1{\def\@tempd{{..} at wrong position: }%
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\@latexerr{%
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\ifcase #1 Illegal pream-token (\@nextchar): `c' used\or %0
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Missing arg: token ignored\or %1
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Empty preamble: `l' used\or %2
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>\@tempd token ignored\or %3
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<\@tempd changed to !{..}\or %4
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Only one colum-spec. allowed.\fi}\@ehc} %5
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\def\@tfor#1:=#2\do#3{\def\@fortmp{#2}\ifx\@fortmp\@empty
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\else\@tforloop#2\@nil\@nil\@@#1{#3}\fi}
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\endinput
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%%
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%% End of file `/usr2/distrib/latex209/nfss/array.sty'.
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@ -29,48 +29,10 @@ The field parsers can be applied to arbitrary strings (one common use is
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splitting environment variables such as \ex{\$PATH} at colons into its
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splitting environment variables such as \ex{\$PATH} at colons into its
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component elements).
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component elements).
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\subsection{Reading delimited strings}
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The general delimited-input procedures described in
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These procedures read in strings from ports delimited by characters
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chapter~\ref{chapt:rdelim} are also useful for reading simple records,
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belonging to a specific set.
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such as single lines, paragraphs of text, or strings terminated by specific
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See section~\ref{sec:char-sets} for information on character set manipulation.
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characters.
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\defun{read-delimited}{char-set [port]} {{\str} or eof}
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\begin{desc}
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Read until we encounter one of the chars in \var{char-set} or eof.
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The terminating character is not included in the string returned,
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nor is it removed from the input stream; the next input operation will
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encounter it. If we get a string back, then \ex{(eof-object? (peek-char))}
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tells if the string was terminated by a delimiter or eof.
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The \var{char-set} argument may be a charset, a string, a character, or a
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character predicate; it is coerced to a charset.
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This operation is likely to be implemented very efficiently. In
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the Scheme 48 implementation, the Unix port case is implemented directly
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in C, and is much faster than the equivalent operation performed
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in Scheme with \ex{peek-char} and \ex{read-char}.
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\end{desc}
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\defun{read-delimited!} {char-set buf [port start end]} {nchars or eof or \#f}
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\begin{desc}
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A side-effecting variant of \ex{read-delimited}.
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The data is written into the string \var{buf} at the indices in the
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half-open interval $[\var{start},\var{end})$; the default interval is the
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whole string: $\var{start}=0$ and $\var{end}=\ex{(string-length
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\var{buf})}$. The values of \var{start} and \var{end} must specify a
|
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well-defined interval in \var{str}, \ie, $0 \le \var{start} \le \var{end}
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\le \ex{(string-length \var{buf})}$.
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It returns \var{nbytes}, the number of bytes read. If the buffer filled up
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without a delimiter character being found, \ex{\#f} is returned. If
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the port is at eof when the read starts, the eof object is returned.
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If an integer is returned, then
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\ex{(eof-object (peek-char port))}
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tells if the string was terminated by a delimiter or eof.
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\end{desc}
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\subsection{Reading records}
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\subsection{Reading records}
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@ -79,21 +41,22 @@ See section~\ref{sec:char-sets} for information on character set manipulation.
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Returns a procedure that reads records from a port. The
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Returns a procedure that reads records from a port. The
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procedure is invoked as follows:
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procedure is invoked as follows:
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%
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%
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\codex{(\var{reader} \var{[port]}) $\longrightarrow$ \emph{{\str} or eof}}
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\codex{(\var{reader} \var{[port]}) $\longrightarrow$
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\textrm{\textit{{\str} or eof}}}
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%
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%
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A record is a sequence of characters terminated by one of the characters
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A record is a sequence of characters terminated by one of the characters
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in \var{delims} or eof. If \var{elide-delims?} is true, then a contiguous
|
in \var{delims} or eof. If \var{elide-delims?} is true, then a contiguous
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sequence of delimiter chars are taken as a single record delimiter. If
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sequence of delimiter chars are taken as a single record delimiter. If
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\var{elide-delims?} is false, then a delimiter char coming immediately
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\var{elide-delims?} is false, then a delimiter char coming immediately
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after a delimiter char produces an empty string record. The reader
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after a delimiter char produces an empty-string record. The reader
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consumes the delimiting char(s) before returning from a read.
|
consumes the delimiting char(s) before returning from a read.
|
||||||
|
|
||||||
The \var{delims} set defaults to the set $\{\rm newline\}$.
|
The \var{delims} set defaults to the set $\{\mbox{newline}\}$.
|
||||||
It may be a charset, string, character, or character predicate,
|
It may be a charset, string, character, or character predicate,
|
||||||
and is coerced to a charset.
|
and is coerced to a charset.
|
||||||
The \var{elide-delims?} flag defaults to \ex{\#f}.
|
The \var{elide-delims?} flag defaults to \ex{\#f}.
|
||||||
|
|
||||||
The \var{handle-delim} controls what is done with the record's
|
The \var{handle-delim} argument controls what is done with the record's
|
||||||
terminating delimiter.
|
terminating delimiter.
|
||||||
\begin{inset}
|
\begin{inset}
|
||||||
\begin{tabular}{lp{0.6\linewidth}}
|
\begin{tabular}{lp{0.6\linewidth}}
|
||||||
|
|
@ -111,18 +74,6 @@ See section~\ref{sec:char-sets} for information on character set manipulation.
|
||||||
a string or eof.
|
a string or eof.
|
||||||
\end{desc}
|
\end{desc}
|
||||||
|
|
||||||
\defun{read-paragraph} {[port delimiter?]} {{\str} or eof}
|
|
||||||
\begin{desc}
|
|
||||||
This procedure skips blank lines,
|
|
||||||
then reads text from a port until a blank line or eof is found.
|
|
||||||
A ``blank line'' is a (possibly empty) line composed only of white space.
|
|
||||||
If \var{delimiter?} is true, the terminating blank line is included in the
|
|
||||||
return string; it defaults to \ex{\#f}. When the delimiter is included,
|
|
||||||
\verb|(match-string "\n[ \t]*\n$" paragraph)|
|
|
||||||
can be used to determine if the paragraph was terminated by a blank line
|
|
||||||
or by eof.
|
|
||||||
\end{desc}
|
|
||||||
|
|
||||||
|
|
||||||
\subsection{Parsing fields}
|
\subsection{Parsing fields}
|
||||||
|
|
||||||
|
|
@ -183,7 +134,7 @@ These functions return a parser function that can be used as follows:
|
||||||
\ex{'trim} & Delimiters are thrown away after parsing. (default) \\
|
\ex{'trim} & Delimiters are thrown away after parsing. (default) \\
|
||||||
\ex{'concat} & Delimiters are appended to the field preceding them. \\
|
\ex{'concat} & Delimiters are appended to the field preceding them. \\
|
||||||
\ex{'split} & Delimiters are returned as separate elements in
|
\ex{'split} & Delimiters are returned as separate elements in
|
||||||
the field vector.
|
the field list.
|
||||||
\end{tabular}
|
\end{tabular}
|
||||||
\end{tightinset}
|
\end{tightinset}
|
||||||
|
|
||||||
|
|
@ -193,7 +144,7 @@ These functions return a parser function that can be used as follows:
|
||||||
error if there are more or fewer than $n$ fields in the record. If
|
error if there are more or fewer than $n$ fields in the record. If
|
||||||
\var{num-fields} is a negative integer or zero, then $|n|$ fields
|
\var{num-fields} is a negative integer or zero, then $|n|$ fields
|
||||||
are parsed, and the remainder of the string is returned in the last
|
are parsed, and the remainder of the string is returned in the last
|
||||||
element of the field vector; it is an error if fewer than $|n|$ fields
|
element of the field list; it is an error if fewer than $|n|$ fields
|
||||||
can be parsed.
|
can be parsed.
|
||||||
|
|
||||||
The field parser produced is a procedure that can be employed as
|
The field parser produced is a procedure that can be employed as
|
||||||
|
|
@ -227,7 +178,7 @@ These functions return a parser function that can be used as follows:
|
||||||
|
|
||||||
It is an error if a non-empty record does not end with a delimiter.
|
It is an error if a non-empty record does not end with a delimiter.
|
||||||
To make the last delimiter optional, make sure the delimiter regexp
|
To make the last delimiter optional, make sure the delimiter regexp
|
||||||
matches the end-of-string \verb|(regexp "$")|.
|
matches the end-of-string (regexp \ex{"\$"}).
|
||||||
|
|
||||||
\item [\ex{infix-splitter}]
|
\item [\ex{infix-splitter}]
|
||||||
Delimiters are interpreted as element \emph{separators}. If comma is the
|
Delimiters are interpreted as element \emph{separators}. If comma is the
|
||||||
|
|
@ -246,16 +197,16 @@ These functions return a parser function that can be used as follows:
|
||||||
\end{tabular}
|
\end{tabular}
|
||||||
\end{inset}
|
\end{inset}
|
||||||
|
|
||||||
Note that separator semantics doesn't really allow for empty records --
|
Note that separator semantics doesn't really allow for empty
|
||||||
the straightforward grammar (\ie, \synvar{real-infix-record}) parses
|
records---the straightforward grammar (\ie, \synvar{real-infix-record})
|
||||||
an empty string as a singleton list whose one field is the empty string,
|
parses an empty string as a singleton list whose one field is the empty
|
||||||
\ex{("")}, not as the empty record \ex{()}. This is unfortunate,
|
string, \ex{("")}, not as the empty record \ex{()}. This is unfortunate,
|
||||||
since it means that infix string parsing doesn't make \ex{string-append}
|
since it means that infix string parsing doesn't make \ex{string-append}
|
||||||
and \ex{vector-append} isomorphic. For example,
|
and \ex{append} isomorphic. For example,
|
||||||
\codex{((infix-splitter ":") (string-append \var{x} ":" \var{y}))}
|
\codex{((infix-splitter ":") (string-append \var{x} ":" \var{y}))}
|
||||||
doesn't always equal
|
doesn't always equal
|
||||||
\begin{code}
|
\begin{code}
|
||||||
(vector-append ((infix-splitter ":") \var{x})
|
(append ((infix-splitter ":") \var{x})
|
||||||
((infix-splitter ":") \var{y}))\end{code}
|
((infix-splitter ":") \var{y}))\end{code}
|
||||||
It fails when \var{x} or \var{y} are the empty string.
|
It fails when \var{x} or \var{y} are the empty string.
|
||||||
Terminator semantics \emph{does} preserve a similar isomorphism.
|
Terminator semantics \emph{does} preserve a similar isomorphism.
|
||||||
|
|
@ -322,7 +273,7 @@ Record & : suffix & \verb!:|$! suffix & : infix & non-: field \\
|
||||||
\subsection{Field readers}
|
\subsection{Field readers}
|
||||||
|
|
||||||
\defun{field-reader} {[field-parser rec-reader]} \proc
|
\defun{field-reader} {[field-parser rec-reader]} \proc
|
||||||
|
\begin{desc}
|
||||||
This utility returns a procedure that reads records with field structure
|
This utility returns a procedure that reads records with field structure
|
||||||
from a port.
|
from a port.
|
||||||
The reader's interface is designed to make it useful in the \ex{awk}
|
The reader's interface is designed to make it useful in the \ex{awk}
|
||||||
|
|
@ -347,10 +298,11 @@ Record & : suffix & \verb!:|$! suffix & : infix & non-: field \\
|
||||||
For example, if port \ex{p} is open on \ex{/etc/passwd}, then
|
For example, if port \ex{p} is open on \ex{/etc/passwd}, then
|
||||||
\codex{((field-reader (infix-splitter ":" 7)) p)}
|
\codex{((field-reader (infix-splitter ":" 7)) p)}
|
||||||
returns two values:
|
returns two values:
|
||||||
\begin{code}
|
{\small
|
||||||
|
\begin{widecode}
|
||||||
"dalbertz:mx3Uaqq0:107:22:David Albertz:/users/dalbertz:/bin/csh"
|
"dalbertz:mx3Uaqq0:107:22:David Albertz:/users/dalbertz:/bin/csh"
|
||||||
("dalbertz" "mx3Uaqq0" "107" "22" "David Albertz" "/users/dalbertz"
|
("dalbertz" "mx3Uaqq0" "107" "22" "David Albertz" "/users/dalbertz"
|
||||||
"/bin/csh")\end{code}
|
"/bin/csh")\end{widecode}}
|
||||||
The \var{field-parser} defaults to the value of \ex{(field-splitter)},
|
The \var{field-parser} defaults to the value of \ex{(field-splitter)},
|
||||||
a parser that picks out sequences of non-white-space strings.
|
a parser that picks out sequences of non-white-space strings.
|
||||||
|
|
||||||
|
|
@ -391,8 +343,10 @@ Record & : suffix & \verb!:|$! suffix & : infix & non-: field \\
|
||||||
\label{fig:field-readers}
|
\label{fig:field-readers}
|
||||||
\end{boxedfigure}
|
\end{boxedfigure}
|
||||||
|
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
\subsection{Forward-progress guarantees and empty string matches}
|
|
||||||
|
\subsection{Forward-progress guarantees and empty-string matches}
|
||||||
A loop that pulls text off a string by repeatedly matching a regexp
|
A loop that pulls text off a string by repeatedly matching a regexp
|
||||||
against that string can conceivably get stuck in an infinite loop if
|
against that string can conceivably get stuck in an infinite loop if
|
||||||
the regexp matches the empty string. For example, the regexps \verb|^|,
|
the regexp matches the empty string. For example, the regexps \verb|^|,
|
||||||
|
|
@ -438,7 +392,7 @@ Unix doesn't support peeking ahead into input streams.
|
||||||
Scsh provides a loop macro and a set of field parsers that can
|
Scsh provides a loop macro and a set of field parsers that can
|
||||||
be used to perform text processing very similar to the Awk programming
|
be used to perform text processing very similar to the Awk programming
|
||||||
language.
|
language.
|
||||||
These basic functionality of Awk is factored in scsh into its component
|
The basic functionality of Awk is factored in scsh into its component
|
||||||
parts.
|
parts.
|
||||||
The control structure is provided by the \ex{awk} loop macro;
|
The control structure is provided by the \ex{awk} loop macro;
|
||||||
the text I/O and parsers are provided by the field-reader subroutine library
|
the text I/O and parsers are provided by the field-reader subroutine library
|
||||||
|
|
@ -477,7 +431,7 @@ these values are bound to the variables given in the
|
||||||
The first value returned is assumed to be the record;
|
The first value returned is assumed to be the record;
|
||||||
when it is the end-of-file object, the loop terminates.
|
when it is the end-of-file object, the loop terminates.
|
||||||
|
|
||||||
For example, let's suppose we want to read items from \etc{/etc/password},
|
For example, let's suppose we want to read items from \ex{/etc/password},
|
||||||
and we use the \ex{field-reader} procedure to define a record parser for
|
and we use the \ex{field-reader} procedure to define a record parser for
|
||||||
\ex{/etc/passwd} entries:
|
\ex{/etc/passwd} entries:
|
||||||
\codex{(define read-passwd (field-reader (infix-splitter ":" 7)))}
|
\codex{(define read-passwd (field-reader (infix-splitter ":" 7)))}
|
||||||
|
|
@ -538,10 +492,10 @@ it checks them all.
|
||||||
|
|
||||||
|
|
||||||
\itum{\begin{tabular}[t]{l}
|
\itum{\begin{tabular}[t]{l}
|
||||||
\ex{(range \var{start-test} \var{stop-test} \vari{body}1 \ldots)} \\
|
\ex{(range\ \ \ \var{start-test} \var{stop-test} \vari{body}1 \ldots)} \\
|
||||||
\ex{(:range \var{start-test} \var{stop-test} \vari{body}1 \ldots)} \\
|
\ex{(:range\ \ \var{start-test} \var{stop-test} \vari{body}1 \ldots)} \\
|
||||||
\ex{(range: \var{start-test} \var{stop-test} \vari{body}1 \ldots)} \\
|
\ex{(range:\ \ \var{start-test} \var{stop-test} \vari{body}1 \ldots)} \\
|
||||||
\ex{(:range: \var{start-test} \var{stop-test} \vari{body}1 \ldots)}
|
\ex{(:range:\ \var{start-test} \var{stop-test} \vari{body}1 \ldots)}
|
||||||
\end{tabular}}
|
\end{tabular}}
|
||||||
%
|
%
|
||||||
These clauses become activated when \var{start-test} is true;
|
These clauses become activated when \var{start-test} is true;
|
||||||
|
|
@ -554,10 +508,10 @@ it checks them all.
|
||||||
The colons control whether or not the start and stop lines
|
The colons control whether or not the start and stop lines
|
||||||
are processed by the clause. For example:
|
are processed by the clause. For example:
|
||||||
\begin{inset}\begin{tabular}{l@{\qquad}l}
|
\begin{inset}\begin{tabular}{l@{\qquad}l}
|
||||||
\ex{(range 1 5 \ldots)} & Lines \phantom{1} 2 3 4 \\
|
\ex{(range\ \ \ 1 5\ \ \ldots)} & Lines \phantom{1} 2 3 4 \\
|
||||||
\ex{(:range 1 5 \ldots)} & Lines 1 2 3 4 \\
|
\ex{(:range\ \ 1 5\ \ \ldots)} & Lines 1 2 3 4 \\
|
||||||
\ex{(range: 1 5 \ldots)} & Lines \phantom{1} 2 3 4 5 \\
|
\ex{(range:\ \ 1 5\ \ \ldots)} & Lines \phantom{1} 2 3 4 5 \\
|
||||||
\ex{(:range: 1 5 \ldots)} & Lines 1 2 3 4 5
|
\ex{(:range: 1 5\ \ \ldots)} & Lines 1 2 3 4 5
|
||||||
\end{tabular}
|
\end{tabular}
|
||||||
\end{inset}
|
\end{inset}
|
||||||
|
|
||||||
|
|
@ -590,7 +544,7 @@ Here are some examples of \ex{awk} being used to process various types
|
||||||
of input stream.
|
of input stream.
|
||||||
|
|
||||||
\begin{code}
|
\begin{code}
|
||||||
(define $ vector-ref) ; Saves typing.
|
(define $ nth) ; Saves typing.
|
||||||
|
|
||||||
;;; Print out the name and home-directory of everyone in /etc/passwd:
|
;;; Print out the name and home-directory of everyone in /etc/passwd:
|
||||||
(let ((read-passwd (field-reader (infix-splitter ":" 7))))
|
(let ((read-passwd (field-reader (infix-splitter ":" 7))))
|
||||||
|
|
@ -614,8 +568,8 @@ of input stream.
|
||||||
|
|
||||||
\begin{code}
|
\begin{code}
|
||||||
;;; Read a series of integers from stdin. This expression evaluates
|
;;; Read a series of integers from stdin. This expression evaluates
|
||||||
;;; to the number of positive numbers were read. Note our "record-reader"
|
;;; to the number of positive numbers that were read. Note our
|
||||||
;;; is the standard Scheme READ procedure.
|
;;; "record-reader" is the standard Scheme READ procedure.
|
||||||
(awk (read) (i) ((npos 0))
|
(awk (read) (i) ((npos 0))
|
||||||
((> i 0) (+ npos 1)))\end{code}
|
((> i 0) (+ npos 1)))\end{code}
|
||||||
|
|
||||||
|
|
|
||||||
|
|
@ -0,0 +1,45 @@
|
||||||
|
% boxedminipage.sty
|
||||||
|
%
|
||||||
|
% adds the boxedminipage environment---just like minipage, but has a
|
||||||
|
% box round it!
|
||||||
|
%
|
||||||
|
% The thickneess of the rules around the box is controlled by
|
||||||
|
% \fboxrule, and the distance between the rules and the edges of the
|
||||||
|
% inner box is governed by \fboxsep.
|
||||||
|
%
|
||||||
|
% This code is based on Lamport's minipage code.
|
||||||
|
|
||||||
|
\def\boxedminipage{\@ifnextchar [{\@iboxedminipage}{\@iboxedminipage[c]}}
|
||||||
|
|
||||||
|
\def\@iboxedminipage[#1]#2{\leavevmode \@pboxswfalse
|
||||||
|
\if #1b\vbox
|
||||||
|
\else \if #1t\vtop
|
||||||
|
\else \ifmmode \vcenter
|
||||||
|
\else \@pboxswtrue $\vcenter
|
||||||
|
\fi
|
||||||
|
\fi
|
||||||
|
\fi\bgroup % start of outermost vbox/vtop/vcenter
|
||||||
|
\hsize #2
|
||||||
|
\hrule\@height\fboxrule
|
||||||
|
\hbox\bgroup % inner hbox
|
||||||
|
\vrule\@width\fboxrule \hskip\fboxsep \vbox\bgroup % innermost vbox
|
||||||
|
\advance\hsize -2\fboxrule \advance\hsize-2\fboxsep
|
||||||
|
\textwidth\hsize \columnwidth\hsize
|
||||||
|
\@parboxrestore
|
||||||
|
\def\@mpfn{mpfootnote}\def\thempfn{\thempfootnote}\c@mpfootnote\z@
|
||||||
|
\let\@footnotetext\@mpfootnotetext
|
||||||
|
\let\@listdepth\@mplistdepth \@mplistdepth\z@
|
||||||
|
\@minipagerestore\@minipagetrue
|
||||||
|
\everypar{\global\@minipagefalse\everypar{}}}
|
||||||
|
|
||||||
|
\def\endboxedminipage{%
|
||||||
|
\par\vskip-\lastskip
|
||||||
|
\ifvoid\@mpfootins\else
|
||||||
|
\vskip\skip\@mpfootins\footnoterule\unvbox\@mpfootins\fi
|
||||||
|
\egroup % ends the innermost \vbox
|
||||||
|
\hskip\fboxsep \vrule\@width\fboxrule
|
||||||
|
\egroup % ends the \hbox
|
||||||
|
\hrule\@height\fboxrule
|
||||||
|
\egroup% ends the vbox/vtop/vcenter
|
||||||
|
\if@pboxsw $\fi}
|
||||||
|
|
||||||
|
|
@ -0,0 +1,258 @@
|
||||||
|
%&latex -*- latex -*-
|
||||||
|
|
||||||
|
\chapter{Changes from the previous release}
|
||||||
|
\label{sec:changes}
|
||||||
|
|
||||||
|
\newcommand{\itam}[1]{\item {#1} \\}
|
||||||
|
|
||||||
|
This section details changes that have been made in scsh since
|
||||||
|
the previous release.
|
||||||
|
|
||||||
|
Scsh is now much more robust.
|
||||||
|
All known bugs have been fixed.
|
||||||
|
There have been many improvements and extensions made.
|
||||||
|
We have also made made some incompatible changes.
|
||||||
|
|
||||||
|
The sections below briefly describe these new features and changes;
|
||||||
|
the relevant sections of the manual give the full details.
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
\section{New features}
|
||||||
|
This release incorporates several new features into scsh.
|
||||||
|
|
||||||
|
\begin{itemize}
|
||||||
|
\itam{Control of buffered I/O}
|
||||||
|
Scsh now allows you to control the buffering policy used for doing I/O
|
||||||
|
on a Scheme port.
|
||||||
|
|
||||||
|
\itam{Here-strings}
|
||||||
|
Scsh now has a new lexical feature, \verb|#<<|, that provides
|
||||||
|
the ability to enter long, multi-line string constants in scsh programs.
|
||||||
|
Such a string is called a ``here string,'' by analogy to the common
|
||||||
|
shell ``here document'' \ex{<<} redirection.
|
||||||
|
|
||||||
|
\itam{Delimited readers and read-line}
|
||||||
|
Scsh now has a powerful set of delimited readers.
|
||||||
|
These can be used to read input delimited by
|
||||||
|
a newline character (\ex{read-line}),
|
||||||
|
a blank line (\ex{read-paragraph}),
|
||||||
|
or the occurrence of any character in an arbitrary set (\ex{read-delimited}).
|
||||||
|
|
||||||
|
While these procedures can be applied to any Scheme input port,
|
||||||
|
there is native-code support for performing delimited reads on
|
||||||
|
Unix input sources, so doing block input with these procedures should be
|
||||||
|
much faster than the equivalent character-at-a-time Scheme code.
|
||||||
|
|
||||||
|
\itam{New system calls}
|
||||||
|
With the sole exception of signal handlers, scsh now has all of {\Posix}.
|
||||||
|
This release introduces
|
||||||
|
\begin{itemize}
|
||||||
|
\item \ex{select},
|
||||||
|
\item full terminal device control,
|
||||||
|
\item support for pseudo-terminal ``pty'' devices,
|
||||||
|
\item file locking,
|
||||||
|
\item process timing,
|
||||||
|
\item \ex{set-file-times},
|
||||||
|
\item \ex{seek} and \ex{tell}.
|
||||||
|
\end{itemize}
|
||||||
|
|
||||||
|
Note that having \ex{select}, pseudo-terminals, and tty device control means
|
||||||
|
that it is now possible to implement interesting network protocols, such as
|
||||||
|
telnet servers and clients, directly in Scheme.
|
||||||
|
|
||||||
|
\itam{New command-line switches}
|
||||||
|
There is a new set of command-line switches that make it possible
|
||||||
|
to write shell scripts using the {\scm} module system.
|
||||||
|
Scripts can use the new command-line switches to open dependent
|
||||||
|
modules and load dependent source code.
|
||||||
|
Scripts can also be written in the {\scm} module language,
|
||||||
|
which allows you to use it both as a standalone shell script,
|
||||||
|
and as a code module that can be loaded and used by other Scheme programs.
|
||||||
|
|
||||||
|
\itam{Static heap linking}
|
||||||
|
There is a new facility that allows you to compile a heap image
|
||||||
|
to a \ex{.o} file that can be linked with the scsh virtual machine.
|
||||||
|
This produces a standalone executable binary, makes startup time
|
||||||
|
near-instantaneous, and greatly improves memory performance---the
|
||||||
|
initial heap image is placed in the process' text pages,
|
||||||
|
where it is shared by different scsh processes, and does not occupy
|
||||||
|
space in the run-time heap.
|
||||||
|
|
||||||
|
\oops{The static heap linker was not documented and installed in time
|
||||||
|
for this release.}
|
||||||
|
|
||||||
|
|
||||||
|
\end{itemize}
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
\section{Incompatible improvements}
|
||||||
|
Some features of scsh have been improved in ways that are
|
||||||
|
not backwards-compatible with previous releases.
|
||||||
|
These changes should not affect most code;
|
||||||
|
however, please note the changes and modify your code accordingly.
|
||||||
|
|
||||||
|
\begin{itemize}
|
||||||
|
\itam{New process-object data-type returned by \ex{fork}}
|
||||||
|
Previous releases were prone to fill up the kernel's process table
|
||||||
|
if a program forked large numbers of processes and subsequently failed
|
||||||
|
to use \ex{wait} to reclaim the entries in the kernel's process table.
|
||||||
|
(This is a problem in standard C environments, as well.)
|
||||||
|
|
||||||
|
Scsh 0.4 introduces a new mechanism for automatically managing subprocesses.
|
||||||
|
Processes are no longer represented by an integer process id,
|
||||||
|
which is impossible to garbage-collect, but by an
|
||||||
|
abstract process data type that encapsulates the process id.
|
||||||
|
All processes are represented using the new data structures;
|
||||||
|
see the relevant section of the manual for further details.
|
||||||
|
|
||||||
|
\itam{Better stdio/current-port synchronisation}
|
||||||
|
The \ex{(begin \ldots)} process form now does a \ex{stdio->stdports}
|
||||||
|
call before executing its body.
|
||||||
|
This means that the Scheme code in the body ``sees'' any external
|
||||||
|
redirections.
|
||||||
|
For example, it means that if a \ex{begin} form in the middle of a pipeline
|
||||||
|
performs I/O on the current input and output ports, it will be communicating
|
||||||
|
with its upstream and downstream pipes.
|
||||||
|
\Eg, this code works as intended without the need for explicit synchronisation:
|
||||||
|
\begin{verbatim}
|
||||||
|
(run (| (gunzip)
|
||||||
|
;; Kill line 1 and insert doubled-sided
|
||||||
|
;; code at head of Postscript.
|
||||||
|
(begin (read-line) ; Eat first line.
|
||||||
|
(display "%!PS-Adobe-2.0\\n")
|
||||||
|
(display "statusdict /setduplexmode known ")
|
||||||
|
(display "{statusdict begin true ")
|
||||||
|
(display "setduplexmode end} if\n")
|
||||||
|
(exec-epf (cat)))
|
||||||
|
(lpr))
|
||||||
|
(< paper.ps))\end{verbatim}
|
||||||
|
Arranging for the \ex{begin} process form to synchronise
|
||||||
|
the current I/O ports with stdio means that all process forms now
|
||||||
|
see their epf's redirections.
|
||||||
|
|
||||||
|
\itam{\ex{file-match} more robust}
|
||||||
|
The \ex{file-match} procedure now catches any error condition
|
||||||
|
signalled by a match procedure,
|
||||||
|
and treats it as if the procedure had simply returned {\sharpf},
|
||||||
|
\ie, match failure.
|
||||||
|
This means \ex{file-match} no longer gets blown out of the water by
|
||||||
|
trying to apply a function like \ex{file-directory?} to a dangling symlink,
|
||||||
|
and other related OS errors.
|
||||||
|
|
||||||
|
\itam{Standard input now unbuffered}
|
||||||
|
Scsh's startup code now makes the initial current input port
|
||||||
|
(corresponding to file descriptor 0) unbuffered.
|
||||||
|
This keeps the shell from ``stealing'' input meant for subprocesses.
|
||||||
|
However, it does slow down character-at-a-time input processing.
|
||||||
|
If you are writing a program that is tolerant of buffered input,
|
||||||
|
and wish the efficiency gains, you can reset the buffering policy
|
||||||
|
yourself.
|
||||||
|
|
||||||
|
\itam{``writeable'' now spelled ``writable''}
|
||||||
|
We inconsistently spelled \ex{file-writable?} and \ex{file-not-writable?}
|
||||||
|
in the manual and the implementation.
|
||||||
|
We have now standardised on the common spelling ``writable'' in both.
|
||||||
|
The older bindings still exist in release 0.4, but will go away in future
|
||||||
|
releases.
|
||||||
|
|
||||||
|
\itam{\protect\ex{char-set-member?} replaced}
|
||||||
|
We have de-released the \ex{char-set-member?} procedure.
|
||||||
|
The scsh 0.3 version of this procedure took arguments
|
||||||
|
in the following order:
|
||||||
|
\codex{(char-set-member? \var{char} \var{char-set})}
|
||||||
|
This argument order is in accordance with standard mathematical useage
|
||||||
|
(\ie, $x \in S$), and also consistent with the R4RS
|
||||||
|
\ex{member}, \ex{memq} and \ex{memv} procedures.
|
||||||
|
It is, however, exactly opposite from the argument order
|
||||||
|
used by the \ex{char-set-member?} in MIT Scheme's character-set library.
|
||||||
|
If we left things as they were, we risked problems with code
|
||||||
|
ported over from MIT Scheme.
|
||||||
|
On the other hand, changing to conformance with MIT Scheme meant
|
||||||
|
inconsistency with common mathematical notation and other long-standing
|
||||||
|
Scheme procedures.
|
||||||
|
Either way was bound to introduce confusion.
|
||||||
|
|
||||||
|
We've taken the approach of simply removing the \ex{char-set-member?}
|
||||||
|
procedure altogether, and replacing it with a new procedure:
|
||||||
|
\codex{(char-set-contains? \var{cset} \var{char})}
|
||||||
|
Note that the argument order is consistent with the name.
|
||||||
|
|
||||||
|
\itam{\ex{file-attributes} now \ex{file-info}}
|
||||||
|
In keeping with the general convention in scsh of naming procedures
|
||||||
|
that retrieve information about system resources \ex{\ldots-info}
|
||||||
|
(\eg, \ex{tty-info}, \ex{user-info}, \ex{group-info}),
|
||||||
|
the \ex{file-attributes} procedure is now named \ex{file-info}.
|
||||||
|
|
||||||
|
We continue to export a \ex{file-attributes} binding for the current
|
||||||
|
release, but it will go away in future releases.
|
||||||
|
|
||||||
|
\itam{Renaming of I/O synchronisation procedures}
|
||||||
|
The \ex{(stdio->stdports \var{thunk})} procedure has been
|
||||||
|
renamed \ex{with-stdio-ports*};
|
||||||
|
there is now a corresponding \ex{with-stdio-ports} special form.
|
||||||
|
The \ex{stdio->stdports} procedure is now a nullary procedure
|
||||||
|
that side-effects the current set of current I/O port bindings.
|
||||||
|
|
||||||
|
\itam{New meta-arg line-two syntax}
|
||||||
|
Scsh now uses a simplified grammar for describing command-line
|
||||||
|
arguments read by the ``meta-arg'' switch from line two of a shell script.
|
||||||
|
If you were using this feature in previous releases, the three incompatible
|
||||||
|
changes of which to be aware are:
|
||||||
|
(1) tab is no longer allowed as an argument delimiter,
|
||||||
|
(2) a run of space characters is not equivalent to a single space,
|
||||||
|
(3) empty arguments are written a different way.
|
||||||
|
\end{itemize}
|
||||||
|
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
\section{Backwards-compatible improvements}
|
||||||
|
|
||||||
|
Some existing features in scsh have been improved in ways that will
|
||||||
|
not effect existing code.
|
||||||
|
|
||||||
|
\begin{itemize}
|
||||||
|
\itam{Improved error reporting}
|
||||||
|
Exception handlers that print out error messages and warnings now
|
||||||
|
print their messages on the error output port,
|
||||||
|
instead of the current output port.
|
||||||
|
Previous releases used the current output port,
|
||||||
|
a problem inherited from Scheme 48.
|
||||||
|
|
||||||
|
Previous scsh releases flushed the Scheme 48 debugging tables when
|
||||||
|
creating the standard scsh heap image.
|
||||||
|
This trimmed the size of the heap image, but made error messages much
|
||||||
|
less comprehensible.
|
||||||
|
We now retain the debugging tables.
|
||||||
|
This bloats the heap image up by about 600kb. And worth it, too.
|
||||||
|
|
||||||
|
(We also have some new techniques for eliminating the run-time memory
|
||||||
|
penalty imposed by these large heap images.
|
||||||
|
Scsh's new static-heap technology allows for this data to be linked
|
||||||
|
into the text pages of the vm's binary, where it will not be touched
|
||||||
|
by the GC or otherwise affect the memory system until it is referenced.)
|
||||||
|
|
||||||
|
Finally, scsh now generates more informative error messages for syscall
|
||||||
|
errors.
|
||||||
|
For example, a file-open error previously told you what the error was
|
||||||
|
(\eg, ``Permission denied,'' or ``No such file or directory''),
|
||||||
|
but not which file you had tried to open.
|
||||||
|
We've improved this.
|
||||||
|
|
||||||
|
\itam{Closing a port twice allowed}
|
||||||
|
Scsh used to generate an error if you attempted to close a port
|
||||||
|
that had already been closed.
|
||||||
|
This is now allowed.
|
||||||
|
The close procedure returns a boolean to indicate whether the port had
|
||||||
|
already been closed or not.
|
||||||
|
|
||||||
|
\itam{Better time precision}
|
||||||
|
The \ex{time+ticks} procedure now returns sub-second precision on OS's
|
||||||
|
that support it.
|
||||||
|
|
||||||
|
\itam{Nicer print-methods for basic data-types}
|
||||||
|
Scsh's standard record types now print more informatively.
|
||||||
|
For example, a process object includes the process id in its
|
||||||
|
printed representation: the process object for process id 2653
|
||||||
|
prints as \verb|#{proc 2653}|.
|
||||||
|
|
||||||
|
\end{itemize}
|
||||||
|
|
@ -0,0 +1,296 @@
|
||||||
|
% code.sty: -*- latex -*-
|
||||||
|
% Latex macros for a "weak" verbatim mode.
|
||||||
|
% -- like verbatim, except \, {, and } have their usual meanings.
|
||||||
|
|
||||||
|
% Environments: code, tightcode, codeaux, codebox, centercode
|
||||||
|
% Commands: \dcd, \cddollar, \cdmath, \cd, \codeallowbreaks, \codeskip, \^
|
||||||
|
% Already defined in LaTeX, but of some relevance: \#, \$, \%, \&, \_, \{, \}
|
||||||
|
|
||||||
|
% Changelog at the end of the file.
|
||||||
|
|
||||||
|
% These commands give you an environment, code, that is like verbatim
|
||||||
|
% except that you can still insert commands in the middle of the environment:
|
||||||
|
% \begin{code}
|
||||||
|
% for(x=1; x<loop_bound; x++)
|
||||||
|
% y += x^3; /* {\em Add in {\tt x} cubed} */
|
||||||
|
% \end{code}
|
||||||
|
%
|
||||||
|
% All characters are ordinary except \{}. To get \{} in your text,
|
||||||
|
% you use the commands \\, \{, and \}.
|
||||||
|
|
||||||
|
% These macros mess with the definition of the special chars (e.g., ^_~%).
|
||||||
|
% The characters \{} are left alone, so you can still have embedded commands:
|
||||||
|
% \begin{code} f(a,b,\ldots,y,z) \end{code}
|
||||||
|
% However, if your embedded commands use the formerly-special chars, as in
|
||||||
|
% \begin{code} x := x+1 /* \mbox{\em This is $y^3$} */ \end{code}
|
||||||
|
% then you lose. The $ and ^ chars are scanned in as non-specials,
|
||||||
|
% so they don't work. If the chars are scanned *outside* the code env,
|
||||||
|
% then you have no problem:
|
||||||
|
% \def\ycube{$y^3$}
|
||||||
|
% \begin{code} x := x+1 /* {\em This is \ycube} */ \end{code}
|
||||||
|
% If you must put special chars inside the code env, you do it by
|
||||||
|
% prefixing them with the special \dcd ("decode") command, that
|
||||||
|
% reverts the chars to back to special status:
|
||||||
|
% \begin{code} x := x+1 /* {\dcd\em This is $y^3$} */ \end{code}
|
||||||
|
% \dcd's scope is bounded by its enclosing braces. It is only defined within
|
||||||
|
% the code env. You can also turn on just $ with the \cddollar command;
|
||||||
|
% you can turn on just $^_ with the \cdmath command. See below.
|
||||||
|
%
|
||||||
|
% Alternatively, just use \(...\) for $...$, \sp for ^, and \sb for _.
|
||||||
|
|
||||||
|
% WARNING:
|
||||||
|
% Like \verb, you cannot put a \cd{...} inside an argument to a macro
|
||||||
|
% or a command. If you try, for example,
|
||||||
|
% \mbox{\cd{$x^y$}}
|
||||||
|
% you will lose. That is because the text "\cd{$x^y$}" gets read in
|
||||||
|
% as \mbox's argument before the \cd executes. But the \cd has to
|
||||||
|
% have a chance to run before LaTeX ever reads the $x^y$ so it can
|
||||||
|
% turn off the specialness of $ and ^. So, \cd has to appear at
|
||||||
|
% top level, not inside an argument. Similarly, you can't have
|
||||||
|
% a \cd or a \code inside a macro (Although you could use \gdef to
|
||||||
|
% define a macro *inside* a \cd, which you could then use outside.
|
||||||
|
% Don't worry about this if you don't understand it.)
|
||||||
|
|
||||||
|
% BUG: In the codebox env, the effect of a \dcd, \cddollar, or \cdmath
|
||||||
|
% command is reset at the end of each line. This can be hacked by
|
||||||
|
% messing with the \halign's preamble, if you feel up to it.
|
||||||
|
|
||||||
|
% Useage note: the initial newline after the \begin{code} or
|
||||||
|
% \begin{codebox} is eaten, but the last newline is not.
|
||||||
|
% So,
|
||||||
|
% \begin{code}
|
||||||
|
% foo
|
||||||
|
% bar
|
||||||
|
% \end{code}
|
||||||
|
% leaves one more blank line after bar than does
|
||||||
|
% \begin{code}
|
||||||
|
% foo
|
||||||
|
% bar\end{code}
|
||||||
|
% Moral: get in the habit of terminating code envs without a newline
|
||||||
|
% (as in the second example).
|
||||||
|
%
|
||||||
|
|
||||||
|
% All this stuff tweaks the meaning of space, tab, and newline.
|
||||||
|
%===============================================================================
|
||||||
|
% \cd@obeyspaces
|
||||||
|
% Turns all spaces into non-breakable spaces.
|
||||||
|
% Note: this is like \@vobeyspaces except without spurious space in defn.
|
||||||
|
% @xobeysp is basically a space; it's defined in latex.tex.
|
||||||
|
%
|
||||||
|
{\catcode`\ =\active\gdef\cd@obeyspaces{\catcode`\ =\active\let =\@xobeysp}}
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
% \cd@obeytabs
|
||||||
|
% Turns all tabs into 8 non-breakable spaces (which is bogus).
|
||||||
|
%
|
||||||
|
{\catcode`\^^I=\active %
|
||||||
|
\gdef\cd@obeytabs{\catcode`\^^I=\active\let^^I=\cd@tab}}
|
||||||
|
|
||||||
|
\def\cd@tab{\@xobeysp\@xobeysp\@xobeysp\@xobeysp\@xobeysp\@xobeysp\@xobeysp\@xobeysp}
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
% \cd@obeylines
|
||||||
|
% Turns all cr's into linebreaks. Pagebreaks are not permitted between lines.
|
||||||
|
% This is copied from lplain.tex's \obeylines, with the cr def'n changed.
|
||||||
|
%
|
||||||
|
{\catcode`\^^M=\active % these lines must end with %
|
||||||
|
\gdef\cd@obeylines{\catcode`\^^M=\active\let^^M=\cd@cr}}
|
||||||
|
|
||||||
|
% What ^M turns into. This def'n keeps blank lines from being compressed out.
|
||||||
|
\def\cd@cr{\par\penalty10000\leavevmode} % TeX magicness
|
||||||
|
%\def\cd@cr{\par\penalty10000\mbox{}} % LaTeX
|
||||||
|
|
||||||
|
|
||||||
|
% \codeallowbreaks
|
||||||
|
% Same as \cd@obeylines, except pagebreaks are allowed.
|
||||||
|
% Put this command inside a code env to allow pagebreaks.
|
||||||
|
|
||||||
|
{\catcode`\^^M=\active % these lines must end with %
|
||||||
|
\gdef\codeallowbreaks{\catcode`\^^M\active\let^^M\cd@crbr}}
|
||||||
|
|
||||||
|
%\def\cd@crbr{\leavevmode\endgraf} % What ^M turns into.
|
||||||
|
\def\cd@crbr{\par\leavevmode} % What ^M turns into.
|
||||||
|
|
||||||
|
|
||||||
|
% \cd@obeycrsp
|
||||||
|
% Turns cr's into non-breakable spaces. Used by \cd.
|
||||||
|
|
||||||
|
{\catcode`\^^M=\active % these lines must end with %
|
||||||
|
\gdef\cd@obeycrsp{\catcode`\^^M=\active\let^^M=\@xobeysp}}
|
||||||
|
|
||||||
|
% =============================================================================
|
||||||
|
|
||||||
|
% Set up code environment, in which most of the common special characters
|
||||||
|
% appearing in code are treated verbatim, namely: $&#^_~%
|
||||||
|
% \ { } are still enabled so that macros can be called in this
|
||||||
|
% environment. Use \\, \{, and \} to use these characters verbatim
|
||||||
|
% in this environment.
|
||||||
|
%
|
||||||
|
% Inside a group, you can make
|
||||||
|
% all the hacked chars special with the \dcd command
|
||||||
|
% $ special with the \cddollar command
|
||||||
|
% $^_ special with the \cdmath command.
|
||||||
|
% If you have a bunch of math $..$'s in your code env, then a global \cddollar
|
||||||
|
% or \cdmath at the beginning of the env can save a lot of trouble.
|
||||||
|
% When chars are special (e.g., after a \dcd), you can still get #$%&_{} with
|
||||||
|
% \#, \$, \%, \&, \_, \{, and \} -- this is standard LaTeX.
|
||||||
|
% Additionally, \\ gives \ inside the code env, and when \cdmath
|
||||||
|
% makes ^ special, it also defines \^ to give ^.
|
||||||
|
|
||||||
|
%The hacked characters can be made special again
|
||||||
|
% within a group by using the \dcd command.
|
||||||
|
|
||||||
|
% Note: this environment allows no breaking of lines whatsoever; not
|
||||||
|
% at spaces or hypens. To arrange for a break use the standard \- command,
|
||||||
|
% or a \discretionary{}{}{} which breaks, but inserts nothing. This is useful,
|
||||||
|
% for example for allowing hypenated identifiers to be broken, e.g.
|
||||||
|
% \def\={\discretionary{}{}{}} %optional break
|
||||||
|
% FOO-\=BAR.
|
||||||
|
|
||||||
|
\def\setupcode{\parsep=0pt\parindent=0pt%
|
||||||
|
\normalfont\ttfamily\frenchspacing\catcode``=13\@noligs%
|
||||||
|
\def\\{\char`\\}%
|
||||||
|
\let\dcd=\cd@dcd\let\cddollar=\cd@dollarspecial\let\cdmath=\cd@mathspecial%
|
||||||
|
\@makeother\$\@makeother\&\@makeother\#%
|
||||||
|
\@makeother\^\@makeother\_\@makeother\~%
|
||||||
|
\@makeother\%\cd@obeytabs\cd@obeyspaces}
|
||||||
|
% other: $&#^_~%
|
||||||
|
% left special: \{}
|
||||||
|
% unnecessary: @`'"
|
||||||
|
|
||||||
|
|
||||||
|
%% codebox, centercode
|
||||||
|
%%=============================================================================
|
||||||
|
%% The codebox env makes a box exactly as wide as it needs to be
|
||||||
|
%% (i.e., as wide as the longest line of code is). This is useful
|
||||||
|
%% if you want to center a chunk of code, or flush it right, or
|
||||||
|
%% something like that. The optional argument to the environment,
|
||||||
|
%% [t], [c], or [b], specifies how to vertically align the codebox,
|
||||||
|
%% just as with arrays or other boxes. Default is [c].
|
||||||
|
|
||||||
|
%% Must be a newline immediately after "\begin{codebox}[t]"!
|
||||||
|
|
||||||
|
{\catcode`\^^M=\active % these lines must end with %
|
||||||
|
\gdef\cd@obeycr{\catcode`\^^M=\active\let^^M=\cr}}
|
||||||
|
|
||||||
|
% If there is a [<letter>] option, then the following newline will
|
||||||
|
% be read *after* ^M is bound to \cr, so we're cool. If there isn't
|
||||||
|
% an option given (i.e., default to [c]), then the @\ifnextchar will
|
||||||
|
% gobble up the newline as it gobbles whitespace. So we insert the
|
||||||
|
% \cr explicitly. Isn't TeX fun?
|
||||||
|
\def\codebox{\leavevmode\@ifnextchar[{\@codebox}{\@codebox[c]\cr}} %]
|
||||||
|
|
||||||
|
\def\@codebox[#1]%
|
||||||
|
{\hbox\bgroup$\if #1t\vtop \else \if#1b\vbox \else \vcenter \fi\fi\bgroup%
|
||||||
|
\tabskip\z@\setupcode\cd@obeycr% just before cd@obey
|
||||||
|
\halign\bgroup##\hfil\span}
|
||||||
|
|
||||||
|
\def\endcodebox{\crcr\egroup\egroup\m@th$\egroup}
|
||||||
|
|
||||||
|
% Center the box on the page:
|
||||||
|
\newenvironment{centercode}%
|
||||||
|
{\begin{center}\begin{codebox}[c]}%
|
||||||
|
{\end{codebox}\end{center}}
|
||||||
|
|
||||||
|
|
||||||
|
%% code, codeaux, tightcode
|
||||||
|
%%=============================================================================
|
||||||
|
%% Code environment as described above. Lines are kept on one page.
|
||||||
|
%% This actually works by setting a huge penalty for breaking
|
||||||
|
%% between lines of code. Code is indented same as other displayed paras.
|
||||||
|
%% Note: to increase left margin, use \begin{codeaux}{\leftmargin=1in}.
|
||||||
|
|
||||||
|
% To allow pagebreaks, say \codeallowbreaks immediately inside the env.
|
||||||
|
% You can allow breaks at specific lines with a \pagebreak form.
|
||||||
|
|
||||||
|
%% N.B.: The \global\@ignoretrue command must be performed just inside
|
||||||
|
%% the *last* \end{...} before the following text. If not, you will
|
||||||
|
%% get an extra space on the following line. Blech.
|
||||||
|
|
||||||
|
%% This environment takes two arguments.
|
||||||
|
%% The second, required argument is the \list parameters to override the
|
||||||
|
%% \@listi... defaults.
|
||||||
|
%% - Usefully set by clients: \topsep \leftmargin
|
||||||
|
%% - Possible, but less useful: \partopsep
|
||||||
|
%% The first, optional argument is the extra \parskip glue that you get around
|
||||||
|
%% \list environments. It defaults to the value of \parskip.
|
||||||
|
\def\codeaux{\@ifnextchar[{\@codeaux}{\@codeaux[\parskip]}} %]
|
||||||
|
\def\@codeaux[#1]#2{%
|
||||||
|
\bgroup\parskip#1%
|
||||||
|
\begin{list}{}%
|
||||||
|
{\parsep\z@\rightskip\z@\listparindent\z@\itemindent\z@#2}%
|
||||||
|
\item[]\setupcode\cd@obeylines}%
|
||||||
|
\def\endcodeaux{\end{list}\leavevmode\egroup\ignorespaces\global\@ignoretrue}
|
||||||
|
|
||||||
|
%% Code env is codeaux with the default margin and spacing \list params:
|
||||||
|
\def\code{\codeaux{}} \let\endcode=\endcodeaux
|
||||||
|
|
||||||
|
%% Like code, but with no extra vertical space above and below.
|
||||||
|
\def\tightcode{\codeaux[=0pt]{\topsep\z@}}%
|
||||||
|
\let\endtightcode\endcodeaux
|
||||||
|
% {\vspace{-1\parskip}\begin{codeaux}{\partopsep\z@\topsep\z@}}%
|
||||||
|
% {\end{codeaux}\vspace{-1\parskip}}
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
% Reasonable separation between lines of code
|
||||||
|
\newcommand{\codeskip}{\penalty0\vspace{2ex}}
|
||||||
|
|
||||||
|
|
||||||
|
% \cd is used to build a code environment in the middle of text.
|
||||||
|
% Note: only difference from display code is that cr's are taken
|
||||||
|
% as unbreakable spaces instead of linebreaks.
|
||||||
|
|
||||||
|
\def\cd{\leavevmode\begingroup\ifmmode\let\startcode=\startmcode\else%
|
||||||
|
\let\startcode\starttcode\fi%
|
||||||
|
\setupcode\cd@obeycrsp\startcode}
|
||||||
|
|
||||||
|
\def\starttcode#1{#1\endgroup}
|
||||||
|
\def\startmcode#1{\hbox{#1}\endgroup}
|
||||||
|
|
||||||
|
|
||||||
|
% Restore $&#^_~% to their normal catcodes
|
||||||
|
% Define \^ to give the ^ char.
|
||||||
|
% \dcd points to this guy inside a code env.
|
||||||
|
\def\cd@dcd{\catcode`\$=3\catcode`\&=4\catcode`\#=6\catcode`\^=7%
|
||||||
|
\catcode`\_=8\catcode`\~=13\catcode`\%=14\def\^{\char`\^}}
|
||||||
|
|
||||||
|
% Selectively enable $, and $^_ as special.
|
||||||
|
% \cd@mathspecial also defines \^ give the ^ char.
|
||||||
|
% \cddollar and \cdmath point to these guys inside a code env.
|
||||||
|
\def\cd@dollarspecial{\catcode`\$=3}
|
||||||
|
\def\cd@mathspecial{\catcode`\$=3\catcode`\^=7\catcode`\_=8%
|
||||||
|
\def\^{\char`\^}}
|
||||||
|
|
||||||
|
|
||||||
|
% Change log:
|
||||||
|
% Started off as some macros found in C. Rich's library.
|
||||||
|
% Olin 1/90:
|
||||||
|
% Removed \makeatletter, \makeatother's -- they shouldn't be there,
|
||||||
|
% because style option files are read with makeatletter. The terminal
|
||||||
|
% makeatother screwed things up for the following style options.
|
||||||
|
% Olin 3/91:
|
||||||
|
% Rewritten.
|
||||||
|
% - Changed things so blank lines don't get compressed out (the \leavevmove
|
||||||
|
% in \cd@cr and \cd@crwb).
|
||||||
|
% - Changed names to somewhat less horrible choices.
|
||||||
|
% - Added lots of doc, so casual hackers can more easily mess with all this.
|
||||||
|
% - Removed `'"@ from the set of hacked chars, since they are already
|
||||||
|
% non-special.
|
||||||
|
% - Removed the bigcode env, which effect can be had with the \codeallowbreaks
|
||||||
|
% command.
|
||||||
|
% - Removed the \@noligs command, since it's already defined in latex.tex.
|
||||||
|
% - Win big with the new \dcd, \cddollar, and \cdmath commands.
|
||||||
|
% - Now, *only* the chars \{} are special inside the code env. If you need
|
||||||
|
% more, use the \dcd command inside a group.
|
||||||
|
% - \cd now works inside math mode. (But if you use it in a superscript,
|
||||||
|
% it still comes out full size. You must explicitly put a \scriptsize\tt
|
||||||
|
% inside the \cd: $x^{\cd{\scriptsize\tt...}}$. A \leavevmode was added
|
||||||
|
% so that if you begin a paragraph with a \cd{...}, TeX realises you
|
||||||
|
% are starting a paragraph.
|
||||||
|
% - Added the codebox env. Tricky bit involving the first line hacked
|
||||||
|
% with help from David Long.
|
||||||
|
% Olin 8/94
|
||||||
|
% Changed the font commands for LaTeX2e.
|
||||||
|
|
@ -0,0 +1,6 @@
|
||||||
|
% Loads cmtt fonts in on \tt. -*- latex -*-
|
||||||
|
% I prefer these to the Courier fonts that latex gives you w/postscript styles.
|
||||||
|
% Courier is too spidery and too wide -- it's hard to get 80 chars on a line.
|
||||||
|
% -Olin
|
||||||
|
|
||||||
|
\renewcommand{\ttdefault}{cmtt}
|
||||||
|
|
@ -0,0 +1,271 @@
|
||||||
|
\makeatletter
|
||||||
|
\def\ie{\mbox{\emph{i.e.}}} % \mbox keeps the last period from
|
||||||
|
\def\Ie{\mbox{\emph{I.e.}}} % looking like an end-of-sentence.
|
||||||
|
\def\eg{\mbox{\emph{e.g.}}}
|
||||||
|
\def\Eg{\mbox{\emph{E.g.}}}
|
||||||
|
\def\etc{{\em etc.}}
|
||||||
|
|
||||||
|
\def\Lisp{\textsc{Lisp}}
|
||||||
|
\def\CommonLisp{\textsc{Common Lisp}}
|
||||||
|
\def\Ascii{\textsc{Ascii}}
|
||||||
|
\def\Ansi{\textsc{Ansi}}
|
||||||
|
\def\Unix{{Unix}} % Not smallcaps, according to Bart.
|
||||||
|
\def\Scheme{{Scheme}}
|
||||||
|
\def\scm{{Scheme 48}}
|
||||||
|
\def\R4RS{R4RS}
|
||||||
|
\def\Posix{\textsc{Posix}}
|
||||||
|
|
||||||
|
\def\sharpf{\normalfont\texttt{\#f}}
|
||||||
|
\def\sharpt{\normalfont\texttt{\#t}}
|
||||||
|
\newcommand{\synteq}{\textnormal{::=}}
|
||||||
|
|
||||||
|
\def\maketildeother{\catcode`\~=12}
|
||||||
|
\def\maketildeactive{\catcode`\~=13}
|
||||||
|
\def\~{\char`\~}
|
||||||
|
|
||||||
|
% One-line code examples
|
||||||
|
%\newcommand{\codex}[1]% One line, centred. Tight spacing.
|
||||||
|
% {$$\abovedisplayskip=.75ex plus 1ex minus .5ex%
|
||||||
|
% \belowdisplayskip=\abovedisplayskip%
|
||||||
|
% \abovedisplayshortskip=0ex plus .5ex%
|
||||||
|
% \belowdisplayshortskip=\abovedisplayshortskip%
|
||||||
|
% \hbox{\ttt #1}$$}
|
||||||
|
%\newcommand{\codex}[1]{\begin{tightinset}\ex{#1}\end{tightinset}\ignorespaces}
|
||||||
|
\newcommand{\codex}[1]{\begin{leftinset}\ex{#1}\end{leftinset}\ignorespaces}
|
||||||
|
|
||||||
|
\def\widecode{\codeaux{\leftmargin=0pt\topsep=0pt}}
|
||||||
|
\def\endwidecode{\endcodeaux}
|
||||||
|
|
||||||
|
% For multiletter vars in math mode:
|
||||||
|
\newcommand{\var}[1]{\mbox{\frenchspacing\it{#1}}}
|
||||||
|
\newcommand{\vari}[2]{${\mbox{\it{#1}}}_{#2}$}
|
||||||
|
|
||||||
|
%% What you frequently want when you say \tt:
|
||||||
|
\def\ttchars{\catcode``=13\@noligs\frenchspacing}
|
||||||
|
\def\ttt{\normalfont\ttfamily\ttchars}
|
||||||
|
|
||||||
|
% Works in math mode; all special chars remain special; cheaper than \cd.
|
||||||
|
% Will not be correct size in super and subscripts, though.
|
||||||
|
\newcommand{\ex}[1]{{\normalfont\texttt{\ttchars #1}}}
|
||||||
|
|
||||||
|
\newenvironment{inset}
|
||||||
|
{\bgroup\parskip=1ex plus 1ex\begin{list}{}%
|
||||||
|
{\topsep=0pt\rightmargin\leftmargin}%
|
||||||
|
\item[]}%
|
||||||
|
{\end{list}\leavevmode\egroup\global\@ignoretrue}
|
||||||
|
|
||||||
|
\newenvironment{leftinset}
|
||||||
|
{\bgroup\parskip=1ex plus 1ex\begin{list}{}%
|
||||||
|
{\topsep=0pt}%
|
||||||
|
\item[]}%
|
||||||
|
{\end{list}\leavevmode\egroup\global\@ignoretrue}
|
||||||
|
|
||||||
|
\newenvironment{tightinset}
|
||||||
|
{\bgroup\parskip=0pt\begin{list}{}%
|
||||||
|
{\topsep=0pt\rightmargin\leftmargin}%
|
||||||
|
\item[]}%
|
||||||
|
{\end{list}\leavevmode\egroup\global\@ignoretrue}
|
||||||
|
|
||||||
|
\newenvironment{tightleftinset}
|
||||||
|
{\bgroup\parskip=0pt\begin{list}{}%
|
||||||
|
{\topsep=0pt}%
|
||||||
|
\item[]}%
|
||||||
|
{\end{list}\leavevmode\egroup\global\@ignoretrue}
|
||||||
|
|
||||||
|
\long\def\remark#1{\bgroup\small\begin{quote}\textsl{Remark: } #1\end{quote}\egroup}
|
||||||
|
\newenvironment{remarkenv}{\bgroup\small\begin{quote}\textsl{Remark: }}%
|
||||||
|
{\end{quote}\egroup}
|
||||||
|
\newcommand{\oops}[1]{\bgroup\small\begin{quote}\textsl{Oops: } #1\end{quote}\egroup}
|
||||||
|
|
||||||
|
\newcommand{\note}[1]{\{Note #1\}}
|
||||||
|
|
||||||
|
\newcommand{\itum}[1]{\item{\bf #1}\\*}
|
||||||
|
|
||||||
|
% For use in code. The \llap magicness makes the lambda exactly as wide as
|
||||||
|
% the other chars in \tt; the \hskip shifts it right a bit so it doesn't
|
||||||
|
% crowd the left paren -- which is necessary if \tt is cmtt.
|
||||||
|
% Note that (\l{x y} (+ x y)) uses the same number of columns in TeX form
|
||||||
|
% as it produces when typeset. This makes it easy to line up the columns
|
||||||
|
% in your input. \l is bound to some useless command in LaTeX, so we have to
|
||||||
|
% define it w/renewcommand.
|
||||||
|
\let\oldl\l %Save the old \l on \oldl
|
||||||
|
\renewcommand{\l}[1]{\ \llap{$\lambda$\hskip-.05em}\ (#1)}
|
||||||
|
|
||||||
|
% This one is for the rare (lambda x ...) case -- it doesn't have the
|
||||||
|
% column-invariant property. Oh, well.
|
||||||
|
\newcommand{\lx}[1]{\ \llap{$\lambda$\hskip-.05em}\ {#1}}
|
||||||
|
|
||||||
|
% For subcaptions
|
||||||
|
\newcommand{\subcaption}[1]
|
||||||
|
{\unskip\vspace{-2mm}\begin{center}\unskip\em#1\end{center}}
|
||||||
|
|
||||||
|
%%% T release notes stuff
|
||||||
|
\newlength{\notewidth}
|
||||||
|
\setlength{\notewidth}{\textwidth}
|
||||||
|
\addtolength{\notewidth}{-1.25in}
|
||||||
|
|
||||||
|
%\newcommand{\remark} [1]
|
||||||
|
% {\par\vspace{\parskip}
|
||||||
|
% \parbox[t]{.75in}{\sc Remark:}
|
||||||
|
% \parbox[t]{\notewidth}{\em #1}
|
||||||
|
% \vspace{\parskip}
|
||||||
|
% }
|
||||||
|
|
||||||
|
\newenvironment{optiontable}%
|
||||||
|
{\begin{tightinset}\renewcommand{\arraystretch}{1.5}%
|
||||||
|
\begin{tabular}{@{}>{\ttt}ll@{}}}%
|
||||||
|
{\end{tabular}\end{tightinset}}%
|
||||||
|
|
||||||
|
\newenvironment{desctable}[1]%
|
||||||
|
{\begin{inset}\renewcommand{\arraystretch}{1.5}%
|
||||||
|
\begin{tabular}{lp{#1}}}%
|
||||||
|
{\end{tabular}\end{inset}}
|
||||||
|
|
||||||
|
\def\*{{\ttt *}}
|
||||||
|
|
||||||
|
% Names of things
|
||||||
|
|
||||||
|
\newcommand{\keyword} [1]{\index{#1}{\normalfont\textsf{#1}}}
|
||||||
|
|
||||||
|
\newcommand{\evalto}{$\Longrightarrow$\ }
|
||||||
|
\renewcommand{\star}{$^*$\/}
|
||||||
|
\newcommand{\+}{$^+$}
|
||||||
|
|
||||||
|
% Semantic domains, used to indicate the type of a value
|
||||||
|
|
||||||
|
\newcommand{\sem}{\normalfont\itshape} %semantic font
|
||||||
|
\newcommand{\semvar}[1]{\textit{#1}} %semantic font
|
||||||
|
\newcommand{\synvar}[1]{\textrm{\textit{$<$#1$>$}}} %syntactic font
|
||||||
|
\newcommand{\type}{\sem}
|
||||||
|
\newcommand{\zeroormore}[1]{{\sem #1$_1$ \ldots #1$_n$}}
|
||||||
|
\newcommand{\oneormore}[1]{{\sem #1$_1$ #1$_2$ \ldots #1$_n$}}
|
||||||
|
|
||||||
|
\newcommand{\proc} {{\sem procedure}}
|
||||||
|
\newcommand{\boolean} {{\sem boolean}}
|
||||||
|
\newcommand{\true} {{\sem true}}
|
||||||
|
\newcommand{\false} {{\sem false}}
|
||||||
|
|
||||||
|
\newcommand{\num} {{\sem number}}
|
||||||
|
\newcommand{\fixnum} {{\sem fixnum}}
|
||||||
|
\newcommand{\integer} {{\sem integer}}
|
||||||
|
\newcommand{\real} {{\sem real}}
|
||||||
|
|
||||||
|
\newcommand{\character} {{\sem character}}
|
||||||
|
\newcommand{\str} {{\sem string}}
|
||||||
|
\newcommand{\sym} {{\sem symbol}}
|
||||||
|
|
||||||
|
\newcommand{\location} {{\sem location}}
|
||||||
|
\newcommand{\object} {{\sem object}}
|
||||||
|
|
||||||
|
\newcommand{\error} {{\sem error}}
|
||||||
|
\newcommand{\syntaxerror} {{\sem syntax error}}
|
||||||
|
\newcommand{\readerror} {{\sem read error}}
|
||||||
|
\newcommand{\undefined} {{\sem undefined}}
|
||||||
|
\newcommand{\noreturn} {{\sem no return value}}
|
||||||
|
|
||||||
|
\newcommand{\port} {{\sem port}}
|
||||||
|
|
||||||
|
% semantic variables
|
||||||
|
|
||||||
|
\newcommand{\identifier} {{\sem identifier}}
|
||||||
|
\newcommand{\identifiers} {\zeroormore{\<ident>}}
|
||||||
|
\newcommand{\expr} {{\sem expression}}
|
||||||
|
\newcommand{\body} {{\sem body}}
|
||||||
|
\newcommand{\valueofbody} {{\sem value~of~body}}
|
||||||
|
\newcommand{\emptylist} {{\sem empty~list}}
|
||||||
|
\newcommand{\car} {\keyword{car}}
|
||||||
|
\newcommand{\cdr} {\keyword{cdr}}
|
||||||
|
|
||||||
|
|
||||||
|
% generally useful things
|
||||||
|
|
||||||
|
% For line-breaking \tt stuff.
|
||||||
|
\renewcommand{\=}{\discretionary{-}{}{-}}
|
||||||
|
\newcommand{\ob}{\discretionary{}{}{}} % Optional break.
|
||||||
|
|
||||||
|
\newcommand{\indx}[1]{#1 \index{ #1 }}
|
||||||
|
%\newcommand{\gloss}[1]{#1 \glossary{ #1 }}
|
||||||
|
|
||||||
|
% This lossage produces #2 if #1 is zero length, otw #3.
|
||||||
|
% We use it to conditionally add a space between the procedure and
|
||||||
|
% the args in procedure prototypes, but only if there are any args--
|
||||||
|
% we want to produce "(read)", not "(read )".
|
||||||
|
\newlength{\voidlen}
|
||||||
|
\newcommand{\testvoid}[3]{\settowidth\voidlen{#1}\ifdim\voidlen>0in{#3}\else{#2}\fi}
|
||||||
|
|
||||||
|
|
||||||
|
% Typeset a definition prototype line, e.g.:
|
||||||
|
% (cons <arg1> <arg2>) -> pair procedure
|
||||||
|
%
|
||||||
|
% Five args are: proc-name args ret-value(s) type index-entry
|
||||||
|
\newcommand{\dfnix}[4]% FIVE args, really.
|
||||||
|
{\hbox to \linewidth{\ttchars%
|
||||||
|
{\ttt(#1\testvoid{#2}{}{\ }{\sem{#2}}\testvoid{#2}{}{\/})\hskip 1em minus
|
||||||
|
0.5em$\longrightarrow$\hskip 1em minus 0.5em{\sem{#3}}\hfill\quad\textnormal{#4}}}\index}
|
||||||
|
|
||||||
|
\newcommand{\dfnx}[4] {\dfnix{#1}{#2}{#3}{#4}{#1@\texttt{#1}}}
|
||||||
|
|
||||||
|
\newcommand{\dfn} {\par\medskip\dfnx} % Takes 4 args, actually.
|
||||||
|
\newcommand{\dfni} {\par\medskip\dfnix} % Takes 5 args, actually.
|
||||||
|
|
||||||
|
\newcommand{\defvar} {\par\medskip\defvarx} % Takes 4 args, actually.
|
||||||
|
\newcommand{\defvarx}[2]%
|
||||||
|
{\index{#1}
|
||||||
|
\hbox to \linewidth{\ttchars{{\ttt{#1}} \hfill #2}}}%
|
||||||
|
|
||||||
|
% Typeset the protocol line, then do the following descriptive text indented.
|
||||||
|
% If you want to group two procs together, do the first one with a \dfn,
|
||||||
|
% then the second one, and the documentation, with a \defndescx.
|
||||||
|
|
||||||
|
% This one doesn't put whitespace above. Use it immediately after a \dfn
|
||||||
|
% to group two prototype lines together.
|
||||||
|
\newenvironment{dfndescx}[4]%
|
||||||
|
{\dfnx{#1}{#2}{#3}{#4}\begin{desc}}{\end{desc}}
|
||||||
|
|
||||||
|
\newenvironment{dfndesc}[4] % This one puts whitespace above.
|
||||||
|
{\par\medskip\begin{dfndescx}{#1}{#2}{#3}{#4}}
|
||||||
|
{\end{dfndescx}}
|
||||||
|
|
||||||
|
\newenvironment{desc}%
|
||||||
|
{\nopagebreak[2]%
|
||||||
|
\smallskip
|
||||||
|
\bgroup\begin{list}{}{\topsep=0pt\parskip=0pt}\item[]}
|
||||||
|
{\end{list}\leavevmode\egroup\global\@ignoretrue}
|
||||||
|
|
||||||
|
\newcommand{\defun} [3] {\dfn{#1}{#2}{#3}{procedure}} % preskip
|
||||||
|
\newcommand{\defunx}[3]{\dfnx{#1}{#2}{#3}{procedure}} % no skip
|
||||||
|
|
||||||
|
\newenvironment{defundescx}[3]%
|
||||||
|
{\begin{dfndescx}{#1}{#2}{#3}{procedure}}
|
||||||
|
{\end{dfndescx}}
|
||||||
|
|
||||||
|
\newenvironment{defundesc}[3]%
|
||||||
|
{\begin{dfndesc}{#1}{#2}{#3}{procedure}}
|
||||||
|
{\end{dfndesc}}
|
||||||
|
|
||||||
|
|
||||||
|
\newenvironment{column}{\begin{tabular}[t]{@{}l@{}}}{\end{tabular}}
|
||||||
|
|
||||||
|
\newenvironment{exampletable}%
|
||||||
|
{\begin{leftinset}%
|
||||||
|
\newcommand{\header}[1]{\multicolumn{2}{@{}l@{}}{##1}\\}%
|
||||||
|
\newcommand{\splitline}[2]%
|
||||||
|
{\multicolumn{2}{@{}l@{}}{##1}\\\multicolumn{2}{@{}l@{}}{\qquad\evalto\quad{##2}}}
|
||||||
|
\begin{tabular}{@{}l@{\quad\evalto\quad}l@{}}}%
|
||||||
|
{\end{tabular}\end{leftinset}}
|
||||||
|
|
||||||
|
% Put on blank lines in a code env to allow a pagebreak.
|
||||||
|
\newcommand{\cb}{\pagebreak[0]}
|
||||||
|
|
||||||
|
\newenvironment{boxedcode}
|
||||||
|
{\begin{inset}\tabular{|l|}\hline}
|
||||||
|
{\\ \hline \end{tabular}\end{inset}}
|
||||||
|
|
||||||
|
% A ragged-right decl that doesn't redefine \\ -- for use in tables.
|
||||||
|
\newcommand{\raggedrightparbox}{\let\temp=\\\raggedright\let\\=\temp}
|
||||||
|
|
||||||
|
\newenvironment{boxedfigure}[1]%
|
||||||
|
{\begin{figure}[#1]\begin{boxedminipage}{\linewidth}\vskip 1.5ex}
|
||||||
|
{\end{boxedminipage}\end{figure}}
|
||||||
|
|
||||||
|
\makeatother
|
||||||
|
|
@ -0,0 +1,76 @@
|
||||||
|
% Document style option "draftfooter"
|
||||||
|
% -- usage: \documentstyle[...,draftfooter,...]{...}
|
||||||
|
% -- puts "DRAFT" with date and time in page footer
|
||||||
|
%
|
||||||
|
% Olin Shivers 1/17/94
|
||||||
|
% - Hacked from code I used in my dissertation and from code in a
|
||||||
|
% drafthead.sty package written by Stephen Page sdpage@uk.ac.oxford.prg.
|
||||||
|
%----------------------------------------------------------------------------
|
||||||
|
|
||||||
|
%
|
||||||
|
% compute the time in hours and minutes; make new variables \timehh and \timemm
|
||||||
|
%
|
||||||
|
\newcount\timehh\newcount\timemm
|
||||||
|
\timehh=\time
|
||||||
|
\divide\timehh by 60 \timemm=\time
|
||||||
|
\count255=\timehh\multiply\count255 by -60 \advance\timemm by \count255
|
||||||
|
%
|
||||||
|
|
||||||
|
\def\draftbox{{\protect\small\bf \fbox{DRAFT}}}
|
||||||
|
\def\drafttime{%
|
||||||
|
{\protect\small\sl\today\ -- \ifnum\timehh<10 0\fi%
|
||||||
|
\number\timehh\,:\,\ifnum\timemm<10 0\fi\number\timemm}}
|
||||||
|
\def\drafttimer{\protect\makebox[0pt][r]{\drafttime}}
|
||||||
|
\def\drafttimel{\protect\makebox[0pt][l]{\drafttime}}
|
||||||
|
|
||||||
|
\def\thepagel{\protect\makebox[0pt][l]{\rm\thepage}}
|
||||||
|
\def\thepager{\protect\makebox[0pt][r]{\rm\thepage}}
|
||||||
|
|
||||||
|
% Header is empty.
|
||||||
|
% Footer is "date DRAFT pageno"
|
||||||
|
\def\ps@plain{
|
||||||
|
\let\@mkboth\@gobbletwo
|
||||||
|
\let\@oddhead\@empty \let\@evenhead\@empty
|
||||||
|
|
||||||
|
\def\@oddfoot{\reset@font\rm\drafttimel\hfil\draftbox\hfil\thepager}
|
||||||
|
\if@twoside
|
||||||
|
\def\@evenfoot{\reset@font\rm\thepagel\hfil\draftbox\hfil\drafttimer}
|
||||||
|
\else \let\@evenfoot\@oddfoot
|
||||||
|
\fi
|
||||||
|
}
|
||||||
|
|
||||||
|
% Aux macro -- sets footer to be "date DRAFT".
|
||||||
|
\def\@draftfooters{
|
||||||
|
\def\@oddfoot{\reset@font\rm\drafttimel\hfil\draftbox}
|
||||||
|
\if@twoside
|
||||||
|
\def\@evenfoot{\reset@font\rm\draftbox\hfil\drafttimer}
|
||||||
|
\else \let\@evenfoot\@oddfoot
|
||||||
|
\fi
|
||||||
|
}
|
||||||
|
|
||||||
|
% Header is empty.
|
||||||
|
% Footer is "date DRAFT".
|
||||||
|
\def\ps@empty{
|
||||||
|
\let\@mkboth\@gobbletwo
|
||||||
|
\let\@oddhead\@empty \let\@evenhead\@empty
|
||||||
|
\@draftfooters
|
||||||
|
}
|
||||||
|
|
||||||
|
% Header is defined by the document style (article, book, etc.).
|
||||||
|
% Footer is "date DRAFT".
|
||||||
|
\let\@draftoldhead\ps@headings
|
||||||
|
\def\ps@headings{
|
||||||
|
\@draftoldhead % Do the default \pagestyle{headings} stuff.
|
||||||
|
\@draftfooters % Then define the draft footers:
|
||||||
|
}
|
||||||
|
|
||||||
|
% Header is defined by the document style (article, book, etc.),
|
||||||
|
% and filled in by user's \markboth and \markright commands.
|
||||||
|
% Footer is "date DRAFT".
|
||||||
|
\let\@draftoldmyhead\ps@myheadings
|
||||||
|
\def\ps@myheadings{
|
||||||
|
\@draftoldmyhead % Do the default \pagestyle{myheadings} stuff.
|
||||||
|
\@draftfooters % Then define the draft footers:
|
||||||
|
}
|
||||||
|
|
||||||
|
\ps@plain
|
||||||
|
|
@ -1,10 +1,10 @@
|
||||||
%&latex -*- latex -*-
|
%&latex -*- latex -*-
|
||||||
|
|
||||||
\title{Scsh Reference Manual}
|
\title{Scsh Reference Manual}
|
||||||
\subtitle{For Scsh release 0.3 \\
|
\subtitle{For scsh release 0.4}
|
||||||
December 25, 1994}
|
% December 25, 1994
|
||||||
\author{Olin Shivers and Brian D.~Carlstrom}
|
\author{Olin Shivers and Brian D.~Carlstrom}
|
||||||
\date{12/94}
|
\date{October 31, 1995}
|
||||||
|
|
||||||
\maketitle
|
\maketitle
|
||||||
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
|
|
||||||
|
|
@ -0,0 +1,16 @@
|
||||||
|
% headings.tex -*- latex -*-
|
||||||
|
% Quieter headings that the ones used in article.sty.
|
||||||
|
% This is not a style option. Don't say [headings].
|
||||||
|
% Instead, say \input{headings} after the \documentstyle.
|
||||||
|
% -Olin 7/91
|
||||||
|
|
||||||
|
\makeatletter
|
||||||
|
|
||||||
|
\def\section{\@startsection {section}{1}{\z@}{-3.5ex plus -1ex minus
|
||||||
|
-.2ex}{2.3ex plus .2ex}{\large\normalfont\bfseries}}
|
||||||
|
\def\subsection{\@startsection{subsection}{2}{\z@}{-3.25ex plus -1ex minus
|
||||||
|
-.2ex}{1.5ex plus .2ex}{\normalsize\normalfont\bfseries}}
|
||||||
|
\def\subsubsection{\@startsection{subsubsection}{3}{\z@}{-3.25ex plus
|
||||||
|
-1ex minus -.2ex}{1.5ex plus .2ex}{\normalsize\normalfont\bfseries}}
|
||||||
|
|
||||||
|
\makeatother
|
||||||
|
|
@ -5,14 +5,86 @@
|
||||||
|
|
||||||
This is a draft manual for scsh, a {\Unix} shell that is embedded within
|
This is a draft manual for scsh, a {\Unix} shell that is embedded within
|
||||||
{\Scheme}.
|
{\Scheme}.
|
||||||
Scsh comes built on top of {\scm}, and it has two components:
|
Scsh is a Scheme system designed for writing useful standalone Unix
|
||||||
|
programs and shell scripts---it spans a wide range of application,
|
||||||
|
from ``script'' applications usually handled with perl or sh,
|
||||||
|
to more standard systems applications usually written in C.
|
||||||
|
|
||||||
|
Scsh comes built on top of {\scm}, and has two components:
|
||||||
a process notation for running programs and setting up pipelines
|
a process notation for running programs and setting up pipelines
|
||||||
and redirections,
|
and redirections,
|
||||||
and a complete syscall library for low-level access to the OS.
|
and a complete syscall library for low-level access to the operating system.
|
||||||
This manual gives a complete description of scsh.
|
This manual gives a complete description of scsh.
|
||||||
A general discussion of the design principles behind scsh can be found
|
A general discussion of the design principles behind scsh can be found
|
||||||
in a companion paper, ``A Scheme Shell.''
|
in a companion paper, ``A Scheme Shell.''
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
\section{Obtaining scsh}
|
||||||
|
Scsh is distributed via net publication.
|
||||||
|
We place new releases at well-known network sites,
|
||||||
|
and allow them to propagate from there.
|
||||||
|
We currently release scsh to the following Internet sites:
|
||||||
|
\begin{inset}\begin{flushleft}
|
||||||
|
\ex{ftp://ftp-swiss.ai.mit.edu/pub/su/} \\
|
||||||
|
\ex{http://www-swiss.ai.mit.edu/scsh/scsh.html}
|
||||||
|
\ex{http://www.cs.indiana.edu/scheme-repository/} \\
|
||||||
|
\end{flushleft}
|
||||||
|
\end{inset}
|
||||||
|
These sites are
|
||||||
|
the MIT Project Mac ftp server,
|
||||||
|
the Scheme Shell home page, and
|
||||||
|
the Indiana Scheme Repository home page,
|
||||||
|
respectively.
|
||||||
|
Each should have a compressed tar file of the entire scsh release,
|
||||||
|
which includes all the source code and the manual,
|
||||||
|
and a separate file containing just this manual in Postscript form,
|
||||||
|
for those who simply wish to read about the system.
|
||||||
|
|
||||||
|
However, nothing is certain for long on the Net.
|
||||||
|
Probably the best way to get a copy of scsh is to use a network
|
||||||
|
resource-discovery tool, such as archie,
|
||||||
|
to find ftp servers storing scsh tar files.
|
||||||
|
Take the set of sites storing the most recent release of scsh,
|
||||||
|
choose one close to your site, and download the tar file.
|
||||||
|
|
||||||
|
\section{Building scsh}
|
||||||
|
Scsh currently runs on a fairly large set of Unix systems, including
|
||||||
|
Linux, NetBSD, SunOS, Solaris, AIX, NeXTSTEP, Irix, and HP-UX.
|
||||||
|
We use the Gnu project's autoconfig tool to generate self-configuring
|
||||||
|
shell scripts that customise the scsh Makefile for different OS variants.
|
||||||
|
This means that if you use one of the common Unix implementations,
|
||||||
|
building scsh should require exactly the following steps:
|
||||||
|
\begin{inset}
|
||||||
|
\begin{tabular}{l@{\qquad}l}
|
||||||
|
\ex{gunzip scsh-0.4.0.tar.gz} & \emph{Uncompress the release tar file.} \\
|
||||||
|
\ex{untar xfv scsh-0.4.0.tar} & \emph{Unpack the source code.} \\
|
||||||
|
\ex{cd scsh-0.4.0} & \emph{Move to the source directory.} \\
|
||||||
|
\ex{./configure} & \emph{Examine host; build Makefile.} \\
|
||||||
|
\ex{make} & \emph{Build system.}
|
||||||
|
\end{tabular}
|
||||||
|
\end{inset}
|
||||||
|
When you are done, you should have a virtual machine compiled in
|
||||||
|
file \ex{scshvm}, and a heap image in file \ex{scsh/scsh.image}.
|
||||||
|
Typing
|
||||||
|
\begin{code}
|
||||||
|
make install
|
||||||
|
\end{code}
|
||||||
|
will install these programs in your installation directory
|
||||||
|
(by default, \ex{/usr/local}), along with a small stub startup
|
||||||
|
binary, \ex{scsh}.
|
||||||
|
|
||||||
|
If you don't have the patience to do this, you can start up
|
||||||
|
a Scheme shell immediately after the initial make by simply
|
||||||
|
saying
|
||||||
|
\codex{./scshvm -o ./scshvm -i scsh/scsh.image}
|
||||||
|
See chapter~\ref{chapt:running} for full details on installation
|
||||||
|
locations and startup options.
|
||||||
|
|
||||||
|
It is not too difficult to port scsh to another Unix platform if your
|
||||||
|
OS is not supported by the current release.
|
||||||
|
See the release notes for more details on how to do this.
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
\section{Caveats}
|
\section{Caveats}
|
||||||
|
|
||||||
It is important to note what scsh is \emph{not}, as well as what it is.
|
It is important to note what scsh is \emph{not}, as well as what it is.
|
||||||
|
|
@ -20,13 +92,13 @@ Scsh, in the current release, is primarily designed for the writing of
|
||||||
shell scripts---programming.
|
shell scripts---programming.
|
||||||
It is not a very comfortable system for interactive command use:
|
It is not a very comfortable system for interactive command use:
|
||||||
the current release lacks job control, command-line editing, a terse,
|
the current release lacks job control, command-line editing, a terse,
|
||||||
convenient command syntax, and it can not be made to read in an initialisation
|
convenient command syntax, and it does not read in an initialisation
|
||||||
file analogous to \ex{.login} or \ex{.profile}.
|
file analogous to \ex{.login} or \ex{.profile}.
|
||||||
We hope to address all of these problems in future releases;
|
We hope to address all of these issues in future releases;
|
||||||
we even have designs for several of these features;
|
we even have designs for several of these features;
|
||||||
but the system as-released does not currently address these issues.
|
but the system as-released does not currently provide these features.
|
||||||
|
|
||||||
As a first release, the system has some rough edges.
|
In the current release, the system has some rough edges.
|
||||||
It is quite slow to start up; we hope to fix that by providing
|
It is quite slow to start up; we hope to fix that by providing
|
||||||
a static-heap linker in the next release.
|
a static-heap linker in the next release.
|
||||||
For now, the initial image load takes about a cpu second.
|
For now, the initial image load takes about a cpu second.
|
||||||
|
|
@ -37,6 +109,7 @@ using markup, so we can generate html, info nodes, and {\TeX} output from
|
||||||
the single source without having to deal with Texinfo.
|
the single source without having to deal with Texinfo.
|
||||||
But it's all there is, for now.
|
But it's all there is, for now.
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
\section{Naming conventions}
|
\section{Naming conventions}
|
||||||
Scsh follows a general naming scheme that consistently employs a set of
|
Scsh follows a general naming scheme that consistently employs a set of
|
||||||
abbreviations.
|
abbreviations.
|
||||||
|
|
@ -90,11 +163,11 @@ Some of the common ones are:
|
||||||
|
|
||||||
\item[\ex{create-}]
|
\item[\ex{create-}]
|
||||||
Procedures that create objects in the file system (files, directories,
|
Procedures that create objects in the file system (files, directories,
|
||||||
temp files, fifos, etc), begin with \ex{create-\ldots}.
|
temp files, fifos, \etc), begin with \ex{create-\ldots}.
|
||||||
|
|
||||||
\item [\ex{delete-}]
|
\item [\ex{delete-}]
|
||||||
Procedures that delete objects from the file system (files,
|
Procedures that delete objects from the file system (files,
|
||||||
directories, temp files, fifos, etc), begin with \ex{delete-\ldots}.
|
directories, temp files, fifos, \etc), begin with \ex{delete-\ldots}.
|
||||||
|
|
||||||
\item[ \ex{\var{record}:\var{field}} ]
|
\item[ \ex{\var{record}:\var{field}} ]
|
||||||
Procedures that access fields of a record are usually written
|
Procedures that access fields of a record are usually written
|
||||||
|
|
@ -118,11 +191,13 @@ For example, the various {\Unix} signal integers have the names
|
||||||
\ex{signal/cont}, \ex{signal/kill}, \ex{signal/int}, \ex{signal/hup},
|
\ex{signal/cont}, \ex{signal/kill}, \ex{signal/int}, \ex{signal/hup},
|
||||||
and so forth.
|
and so forth.
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
\section{Lexical issues}
|
\section{Lexical issues}
|
||||||
Scsh's lexical syntax is just {\R4RS} {\Scheme}, with the following
|
Scsh's lexical syntax is just {\R4RS} {\Scheme}, with the following
|
||||||
exceptions.
|
exceptions.
|
||||||
|
|
||||||
Scsh differs from {\R4RS} {\Scheme} in the following ways:
|
\subsection{Extended symbol syntax}
|
||||||
|
Scsh's symbol syntax differs from {\R4RS} {\Scheme} in the following ways:
|
||||||
\begin{itemize}
|
\begin{itemize}
|
||||||
\item In scsh, symbol case is preserved by \ex{read} and is significant on
|
\item In scsh, symbol case is preserved by \ex{read} and is significant on
|
||||||
symbol comparison. This means
|
symbol comparison. This means
|
||||||
|
|
@ -132,10 +207,7 @@ Scsh differs from {\R4RS} {\Scheme} in the following ways:
|
||||||
\item ``\ex{-}'' and ``\ex{+}'' are allowed to begin symbols.
|
\item ``\ex{-}'' and ``\ex{+}'' are allowed to begin symbols.
|
||||||
So the following are legitimate symbols:
|
So the following are legitimate symbols:
|
||||||
\codex{-O2 -geometry +Wn}
|
\codex{-O2 -geometry +Wn}
|
||||||
\end{itemize}
|
|
||||||
%
|
|
||||||
Scsh also extends {\R4RS} lexical syntax in the following ways:
|
|
||||||
\begin{itemize}
|
|
||||||
\item ``\ex{|}'' and ``\ex{.}'' are symbol constituents.
|
\item ``\ex{|}'' and ``\ex{.}'' are symbol constituents.
|
||||||
This allows \ex{|} for the pipe symbol, and \ex{..} for the parent-directory
|
This allows \ex{|} for the pipe symbol, and \ex{..} for the parent-directory
|
||||||
symbol. (Of course, ``\ex{.}'' alone is not a symbol, but a
|
symbol. (Of course, ``\ex{.}'' alone is not a symbol, but a
|
||||||
|
|
@ -144,16 +216,119 @@ Scsh also extends {\R4RS} lexical syntax in the following ways:
|
||||||
\item A symbol may begin with a digit.
|
\item A symbol may begin with a digit.
|
||||||
So the following are legitimate symbols:
|
So the following are legitimate symbols:
|
||||||
\codex{9x15 80x36-3+440}
|
\codex{9x15 80x36-3+440}
|
||||||
|
|
||||||
\item Strings are allowed to contain the {\Ansi} C escape sequences
|
|
||||||
such as \verb|\n| and \verb|\161|.
|
|
||||||
|
|
||||||
\item \ex{\#!} is a comment read-macro similar to \ex{;}.
|
|
||||||
This is used to write shell scripts. When the reader
|
|
||||||
encounters \ex{\#!}, it skips characters until it finds
|
|
||||||
the sequence new\-line/{\ob}ex\-cla\-ma\-tion-{\ob}point/{\ob}sharp-{\ob}sign/{\ob}new\-line.
|
|
||||||
\end{itemize}
|
\end{itemize}
|
||||||
|
|
||||||
|
\subsection{Extended string syntax}
|
||||||
|
Scsh strings are allowed to contain the {\Ansi} C escape sequences
|
||||||
|
such as \verb|\n| and \verb|\161|.
|
||||||
|
|
||||||
|
\subsection{Block comments and executable interpreter-triggers}
|
||||||
|
Scsh allows source files to begin with a header of the form
|
||||||
|
\codex{\#!/usr/local/bin/scsh -s}
|
||||||
|
The Unix operating system treats source files beginning with the headers
|
||||||
|
of this form specially;
|
||||||
|
they can be directly executed by the operating system
|
||||||
|
(see chapter~\ref{chapt:running} for information on how to use this feature).
|
||||||
|
The scsh interpreter ignores this special header by treating \ex{\#!} as a
|
||||||
|
comment marker similar to \ex{;}.
|
||||||
|
When the scsh reader encounters \ex{\#!}, it skips characters until it finds
|
||||||
|
the closing sequence
|
||||||
|
new\-line/{\ob}ex\-cla\-ma\-tion-{\ob}point/{\ob}sharp-{\ob}sign/{\ob}new\-line.
|
||||||
|
|
||||||
|
Although the form of the \ex{\#!} read-macro was chosen to support
|
||||||
|
interpreter-triggers for executable Unix scripts,
|
||||||
|
it is a general block-comment sequence and can be used as such
|
||||||
|
anywhere in a scsh program.
|
||||||
|
|
||||||
|
\subsection{Here-strings}
|
||||||
|
The read macro \ex{\#<} is used to introduce ``here-strings''
|
||||||
|
in programs, similar to the \ex{<<} ``here document'' redirections
|
||||||
|
provided by sh and csh.
|
||||||
|
There are two kinds of here-string, character-delimited and line-delimited;
|
||||||
|
they are both introduced by the \ex{\#<} sequence.
|
||||||
|
|
||||||
|
\subsubsection{Character-delimited here-strings}
|
||||||
|
A \emph{character-delimited} here-string has the form
|
||||||
|
\codex{\#<\emph{x}...stuff...\emph{x}}
|
||||||
|
where \emph{x} is any single character
|
||||||
|
(except \ex{<}, see below),
|
||||||
|
which is used to delimit the string bounds.
|
||||||
|
Some examples:
|
||||||
|
\begin{inset}
|
||||||
|
\begin{tabular}{ll}
|
||||||
|
Here-string syntax & Ordinary string syntax \\ \hline
|
||||||
|
\verb:#<|Hello, world.|: & \verb:"Hello, world.": \\
|
||||||
|
\verb:#<!"Ouch," he said.!: & \verb:"\"Ouch,\" he said.":
|
||||||
|
\end{tabular}
|
||||||
|
\end{inset}
|
||||||
|
%
|
||||||
|
There is no interpretation of characters within the here-string;
|
||||||
|
the characters are all copied verbatim.
|
||||||
|
|
||||||
|
\subsubsection{Line-delimited here-strings}
|
||||||
|
If the sequence begins "\ex{\#<<}" then it introduces a \emph{line-delimited}
|
||||||
|
here-string.
|
||||||
|
These are similar to the ``here documents'' of sh and csh.
|
||||||
|
Line-delimited here-strings are delimited by the rest of the text line that
|
||||||
|
follows the "\ex{\#<<}" sequence.
|
||||||
|
For example:
|
||||||
|
|
||||||
|
\begin{code}
|
||||||
|
#<<FOO
|
||||||
|
Hello, there.
|
||||||
|
This is read by Scheme as a string,
|
||||||
|
terminated by the first occurrence
|
||||||
|
of newline-F-O-O-newline or newline-F-O-O-eof.
|
||||||
|
FOO\end{code}
|
||||||
|
%
|
||||||
|
Thus,
|
||||||
|
\begin{code}
|
||||||
|
#<<foo
|
||||||
|
Hello, world.
|
||||||
|
foo\end{code}
|
||||||
|
%
|
||||||
|
is the same thing as
|
||||||
|
\codex{"Hello, world."}
|
||||||
|
|
||||||
|
Line-delimited here-strings are useful for writing down long, constant
|
||||||
|
strings---such as long, multi-line \ex{format} strings,
|
||||||
|
or arguments to Unix programs, \eg,
|
||||||
|
\begin{code}
|
||||||
|
;; Free up some disk space for my netnews files.
|
||||||
|
(run (csh -c #<<EOF
|
||||||
|
cd /urops
|
||||||
|
rm -rf *
|
||||||
|
echo All done.
|
||||||
|
|
||||||
|
EOF
|
||||||
|
))\end{code}
|
||||||
|
|
||||||
|
The advantage they have over the double-quote syntax
|
||||||
|
(\eg, \ex{"Hello, world."})
|
||||||
|
is that there is no need to backslash-quote special characters internal
|
||||||
|
to the string, such as the double-quote or backslash characters.
|
||||||
|
|
||||||
|
The detailed syntax of line-delimited here-strings is as follows.
|
||||||
|
The characters "\ex{\#<<}" begin the here-string.
|
||||||
|
The characters between the "\ex{\#<<}" and the next newline are the
|
||||||
|
\emph{delimiter line}.
|
||||||
|
All characters between the "\ex{\#<<}" and the next newline comprise the
|
||||||
|
delimiter line---including any white space.
|
||||||
|
The body of the string begins on the following line,
|
||||||
|
and is terminated by a line of text which exactly matches the
|
||||||
|
delimiter line.
|
||||||
|
This terminating line can be ended by either a newline or end-of-file.
|
||||||
|
Absolutely no interpretation is done on the input string.
|
||||||
|
Control characters, white space, quotes, backslash---everything
|
||||||
|
is copied as-is.
|
||||||
|
The newline immediately preceding the terminating delimiter line is
|
||||||
|
not included in the result string
|
||||||
|
(leave an extra blank line if you need to put a final
|
||||||
|
newline in the here-string---see the example above).
|
||||||
|
If EOF is encountered before reading the end of the here-string,
|
||||||
|
an error is signalled.
|
||||||
|
|
||||||
|
\subsection{Dot}
|
||||||
It is unfortunate that the single-dot token, ``\ex{.}'', is both
|
It is unfortunate that the single-dot token, ``\ex{.}'', is both
|
||||||
a fundamental {\Unix} file name and a deep, primitive syntactic token
|
a fundamental {\Unix} file name and a deep, primitive syntactic token
|
||||||
in {\Scheme}---it means the following will not parse correctly in scsh:
|
in {\Scheme}---it means the following will not parse correctly in scsh:
|
||||||
|
|
@ -161,6 +336,76 @@ in {\Scheme}---it means the following will not parse correctly in scsh:
|
||||||
You must instead quote the dot:
|
You must instead quote the dot:
|
||||||
\codex{(run/strings (find "." -name *.c -print))}
|
\codex{(run/strings (find "." -name *.c -print))}
|
||||||
|
|
||||||
|
When you write shell scripts that manipulate the file system,
|
||||||
|
keep in mind the special status of the dot token.
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
\section{Record types and the \texttt{define-record} form}
|
||||||
|
\label{sec:defrec}
|
||||||
|
\index{define-record@\texttt{define-record}}
|
||||||
|
|
||||||
|
Scsh's interfaces occasionally provide data in structured record types;
|
||||||
|
an example is the \ex{file-info} record whose various fields describe the size,
|
||||||
|
protection, last date of modification, and other pertinent data for a
|
||||||
|
particular file.
|
||||||
|
These record types are described in this manual using the \ex{define-record}
|
||||||
|
notation, which looks like the following:
|
||||||
|
%
|
||||||
|
\begin{code}
|
||||||
|
(define-record ship
|
||||||
|
x
|
||||||
|
y
|
||||||
|
(size 100))\end{code}
|
||||||
|
%
|
||||||
|
This form defines a \var{ship} record, with three fields:
|
||||||
|
its x and y coordinates, and its size.
|
||||||
|
The values of the \var{x} and \var{y} fields are specified as parameters
|
||||||
|
to the ship-building procedure, \ex{(make-ship \var{x} \var{y})},
|
||||||
|
and the \var{size} field is initialised to 100.
|
||||||
|
All told, the \ex{define-record} form above defines the following procedures:
|
||||||
|
%
|
||||||
|
\begin{center}
|
||||||
|
\begin{tabular}{|ll|}
|
||||||
|
\multicolumn{1}{l}{Procedure} & \multicolumn{1}{l}{Definition} \\
|
||||||
|
\hline
|
||||||
|
(make-ship \var{x} \var{y}) & Create a new \var{ship} record. \\
|
||||||
|
\hline
|
||||||
|
(ship:x \var{ship}) & Retrieve the \var{x} field. \\
|
||||||
|
(ship:y \var{ship}) & Retrieve the \var{y} field. \\
|
||||||
|
(ship:size \var{ship}) & Retrieve the \var{size} field. \\
|
||||||
|
\hline
|
||||||
|
(set-ship:x \var{ship} \var{new-x}) & Assign the \var{x} field. \\
|
||||||
|
(set-ship:y \var{ship} \var{new-y}) & Assign the \var{x} field. \\
|
||||||
|
(set-ship:size \var{ship} \var{new-size}) & Assign the \var{size} field. \\
|
||||||
|
\hline
|
||||||
|
(ship? \var{object}) & Type predicate. \\
|
||||||
|
\hline
|
||||||
|
\end{tabular}
|
||||||
|
\end{center}
|
||||||
|
%
|
||||||
|
|
||||||
|
An implementation of \ex{define-record} is available as a macro for Scheme
|
||||||
|
programmers to define their own record types;
|
||||||
|
the syntax is accessed by opening the package \ex{defrec-package}, which
|
||||||
|
exports the single syntax form \ex{define-record}.
|
||||||
|
|
||||||
|
You must open this package to access the form.
|
||||||
|
Scsh does not export a record-definition package by default as there are
|
||||||
|
several from which to choose.
|
||||||
|
Besides the \ex{define-record} macro, which Shivers prefers\footnote{He wrote
|
||||||
|
it.}, you might instead wish to employ the notationally-distinct
|
||||||
|
\ex{define-record-type} macro that Jonathan Rees
|
||||||
|
prefers,\footnote{He wrote it.}
|
||||||
|
or the identically named but wholly different \ex{define-record-type}
|
||||||
|
macro that Richard Kelsey prefers.\footnote{He wrote it.}
|
||||||
|
The former can be found in file \ex{rts/jar-defrecord.scm} and package
|
||||||
|
\ex{define-record-types}; the latter can be found in file
|
||||||
|
\ex{big/defrecord.scm} and package \ex{defrecord}.
|
||||||
|
|
||||||
|
Alternatively, you may define your own, of course.
|
||||||
|
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
\section{A word about {\Unix} standards}
|
\section{A word about {\Unix} standards}
|
||||||
``The wonderful thing about {\Unix} standards is that there are so many
|
``The wonderful thing about {\Unix} standards is that there are so many
|
||||||
to choose from.''
|
to choose from.''
|
||||||
|
|
@ -185,5 +430,8 @@ supports all of it.
|
||||||
The guerilla PC {\Unix} implementations that have been springing up on
|
The guerilla PC {\Unix} implementations that have been springing up on
|
||||||
the net (\eg, NetBSD, Linux, FreeBSD, and so forth) are only recently coming
|
the net (\eg, NetBSD, Linux, FreeBSD, and so forth) are only recently coming
|
||||||
into compliance with the standard---although they are getting there.
|
into compliance with the standard---although they are getting there.
|
||||||
We've found a few small problems with NeXTSTEP's {\Posix} support that
|
We have been able to implement scsh completely on all of these systems,
|
||||||
we had to work around.
|
however---the single exception is NeXTSTEP, whose buggy {\Posix} libraries
|
||||||
|
restricts us to partial support (these lacunae are indicated where relevant
|
||||||
|
in the rest of the manual).\footnote{Feel like porting scsh from {\Posix} to
|
||||||
|
NeXT's BSD API? Send us your fixes; we'll fold them in.}
|
||||||
|
|
|
||||||
|
|
@ -0,0 +1,46 @@
|
||||||
|
%&latex -*- latex -*-
|
||||||
|
|
||||||
|
% This is the reference manual for the Scheme Shell.
|
||||||
|
|
||||||
|
\documentclass[twoside]{report}
|
||||||
|
\usepackage{code,boxedminipage,draftfooters,makeidx,palatino,ct,
|
||||||
|
headings,mantitle,array,matter,mysize10}
|
||||||
|
|
||||||
|
% Style issues
|
||||||
|
\parskip = 3pt plus 3pt
|
||||||
|
\sloppy
|
||||||
|
|
||||||
|
\input{decls}
|
||||||
|
\makeindex
|
||||||
|
%%% End preamble
|
||||||
|
|
||||||
|
\begin{document}
|
||||||
|
|
||||||
|
\frontmatter
|
||||||
|
\include{front}
|
||||||
|
|
||||||
|
\mainmatter
|
||||||
|
\include{intro}
|
||||||
|
\include{procnotation}
|
||||||
|
\include{syscalls}
|
||||||
|
\include{network}
|
||||||
|
\include{strings}
|
||||||
|
\include{rdelim}
|
||||||
|
\include{awk}
|
||||||
|
\include{miscprocs}
|
||||||
|
\include{running}
|
||||||
|
\include{changes}
|
||||||
|
\include{todo}
|
||||||
|
|
||||||
|
\backmatter
|
||||||
|
\printindex
|
||||||
|
|
||||||
|
\end{document}
|
||||||
|
|
||||||
|
% General things to do when converting ASCII text to LaTeX:
|
||||||
|
% Build a set of \breakondash, \breakondot, \breakonslash commands
|
||||||
|
% that will enable breaking in \tt. This is better than \=, etc.
|
||||||
|
%
|
||||||
|
% Check for ..., quote char, double-dashes --
|
||||||
|
% Double-word check
|
||||||
|
% lambda -> \l
|
||||||
|
|
@ -0,0 +1,75 @@
|
||||||
|
% This is the title page style stolen from the Texinfo design,
|
||||||
|
% and expressed as a LaTeX style option. It is useful for manuals.
|
||||||
|
%
|
||||||
|
% Note that I play some *really* revolting games here to override
|
||||||
|
% the vertical and horizontal margins temporarily for the title page.
|
||||||
|
% The layout assumes you have 8.5" x 11" paper. You'd have to redo this
|
||||||
|
% for A4 or another size.
|
||||||
|
% -Olin 7/94
|
||||||
|
|
||||||
|
|
||||||
|
% Fonts for title page:
|
||||||
|
\DeclareFixedFont{\titlefont}%
|
||||||
|
{\encodingdefault}{\familydefault}{bx}{\shapedefault}{20.5pt}
|
||||||
|
\DeclareFixedFont{\authorfnt}%
|
||||||
|
{\encodingdefault}{\familydefault}{bx}{\shapedefault}{14.4pt}
|
||||||
|
\DeclareFixedFont{\subtitlefnt}%
|
||||||
|
{\encodingdefault}{\familydefault}{m}{\shapedefault}{11}
|
||||||
|
|
||||||
|
%\def\authorrm{\normalfont\selectfont\fontseries{bx}\fontsize{14.4}{14.4}}
|
||||||
|
%\def\subtitlefnt{\normalfont\selectfont\fontsize{11}{11}}
|
||||||
|
|
||||||
|
\newskip\titlepagetopglue \titlepagetopglue = 2.5in
|
||||||
|
|
||||||
|
|
||||||
|
\newlength{\widewidth}
|
||||||
|
\setlength{\widewidth}{6.5in}
|
||||||
|
\newlength{\negwidemargin}
|
||||||
|
\setlength{\negwidemargin}{-\oddsidemargin} % Reset the margin
|
||||||
|
\addtolength{\negwidemargin}{-1in} % to edge of page
|
||||||
|
\addtolength{\negwidemargin}{1in} % Then move right one inch.
|
||||||
|
|
||||||
|
%\def\wideline#1{\hbox to 0pt{\hspace\negwidemargin\hbox to\widewidth{#1}}}
|
||||||
|
\def\wideline#1{\hbox{\makebox[0pt][l]{\hspace\negwidemargin\hbox to\widewidth{#1}}}}
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
\def\maketitle{\begin{titlepage}
|
||||||
|
\thispagestyle{empty}
|
||||||
|
\let\footnotesize\small \let\footnoterule\relax
|
||||||
|
\null
|
||||||
|
\parindent=0pt
|
||||||
|
\def\subtitlefont{\normalbaselineskip = 13pt \normalbaselines \subtitlefnt}%
|
||||||
|
\def\authorfont{\normalbaselineskip = 16pt \normalbaselines \authorfnt}%
|
||||||
|
%
|
||||||
|
% Leave some space at the very top of the page.
|
||||||
|
\vspace*{-1in}\vspace*{-\topmargin}\vspace*{-\headheight}\vspace*{-\headsep}
|
||||||
|
\vglue\titlepagetopglue
|
||||||
|
%
|
||||||
|
\wideline{\titlefont \@title \hfill} % title
|
||||||
|
% \vskip4pt
|
||||||
|
\vskip -0.3\baselineskip
|
||||||
|
\wideline{\leaders\hrule height 4pt\hfill}
|
||||||
|
\wideline{\hfill\subtitlefont\begin{tabular}[t]{@{}r@{}}\@subtitle%
|
||||||
|
\end{tabular}\hskip 1in} % subtitle
|
||||||
|
%
|
||||||
|
% author
|
||||||
|
\vskip 0pt plus 1filll
|
||||||
|
\wideline{\authorfont \begin{tabular}[t]{@{}c@{}}\@author
|
||||||
|
\end{tabular}\hfill}
|
||||||
|
%
|
||||||
|
% \vskip4pt
|
||||||
|
\vskip -0.3\baselineskip
|
||||||
|
\wideline{\leaders\hrule height 2pt\hfill}
|
||||||
|
|
||||||
|
% This weirdness puts the bottom line 2.75 in from the bottom of
|
||||||
|
% an 11in page.
|
||||||
|
\vskip \textheight \vskip \headsep \vskip \headheight
|
||||||
|
\vskip \topmargin \vskip 1in \vskip -11in \vskip 2.75in
|
||||||
|
|
||||||
|
\gdef\@author{}\gdef\@title{}\gdef\@subtitle{}\let\maketitle\relax
|
||||||
|
\end{titlepage}
|
||||||
|
\setcounter{page}{2}
|
||||||
|
}
|
||||||
|
|
||||||
|
\def\subtitle#1{\gdef\@subtitle{#1}}
|
||||||
|
\def\@subtitle{}
|
||||||
|
|
@ -0,0 +1,16 @@
|
||||||
|
%&latex -*- latex -*-
|
||||||
|
% Implement the \frontmatter, \mainmatter, and \backmatter macros,
|
||||||
|
% so I can use them in reports, not just books.
|
||||||
|
|
||||||
|
\newif\if@mainmatter \@mainmattertrue
|
||||||
|
|
||||||
|
\newcommand\frontmatter{%
|
||||||
|
\cleardoublepage\@mainmatterfalse\pagenumbering{roman}}
|
||||||
|
|
||||||
|
\newcommand\mainmatter{%
|
||||||
|
\cleardoublepage\@mainmattertrue%
|
||||||
|
\pagenumbering{arabic}\setcounter{page}{1}}
|
||||||
|
|
||||||
|
\newcommand\backmatter{%
|
||||||
|
\if@openright\cleardoublepage\else\clearpage\fi%
|
||||||
|
\@mainmatterfalse}
|
||||||
|
|
@ -3,6 +3,7 @@
|
||||||
\chapter{Miscellaneous routines}
|
\chapter{Miscellaneous routines}
|
||||||
|
|
||||||
\section{Integer bitwise ops}
|
\section{Integer bitwise ops}
|
||||||
|
\label{sec:bitwise}
|
||||||
\defun{arithmetic-shift} {i j} \integer
|
\defun{arithmetic-shift} {i j} \integer
|
||||||
\defunx {bitwise-and} {i j} \integer
|
\defunx {bitwise-and} {i j} \integer
|
||||||
\defunx {bitwise-ior} {i j} \integer
|
\defunx {bitwise-ior} {i j} \integer
|
||||||
|
|
@ -39,4 +40,6 @@ from the lists returned by the field-readers (chapter~\ref{chapt:fr-awk}).
|
||||||
and want to be able to recover your shell state, you can
|
and want to be able to recover your shell state, you can
|
||||||
fork off a subshell with the following form:
|
fork off a subshell with the following form:
|
||||||
\codex{(run (begin (repl)))}
|
\codex{(run (begin (repl)))}
|
||||||
|
{\ldots}or, rephrased for the proceduralists:
|
||||||
|
\codex{(wait (fork repl))}
|
||||||
\end{desc}
|
\end{desc}
|
||||||
|
|
|
||||||
|
|
@ -0,0 +1,22 @@
|
||||||
|
%&latex -*- latex -*-
|
||||||
|
\if@twoside
|
||||||
|
\oddsidemargin 44pt
|
||||||
|
\evensidemargin 82pt
|
||||||
|
\marginparwidth 107pt
|
||||||
|
\else
|
||||||
|
\oddsidemargin 63pt
|
||||||
|
\evensidemargin 63pt
|
||||||
|
\marginparwidth 90pt
|
||||||
|
\fi
|
||||||
|
\marginparsep 11pt
|
||||||
|
|
||||||
|
\topmargin 27pt
|
||||||
|
\headheight 12pt
|
||||||
|
\headsep 25pt
|
||||||
|
\topskip = 10pt
|
||||||
|
\footskip 30pt
|
||||||
|
|
||||||
|
\textheight = 43\baselineskip
|
||||||
|
\advance\textheight by \topskip
|
||||||
|
\textwidth 345pt
|
||||||
|
\endinput
|
||||||
|
|
@ -9,23 +9,21 @@ standard).
|
||||||
However, Berkeley sockets are a \emph{de facto} standard,
|
However, Berkeley sockets are a \emph{de facto} standard,
|
||||||
being found on most Unix workstations and PC operating systems.
|
being found on most Unix workstations and PC operating systems.
|
||||||
|
|
||||||
Future releases of scsh will contain more high-level support for
|
It is fairly straightforward to add higher-level network protocols
|
||||||
networking applications.
|
such as smtp, telnet, or http on top of the the basic socket-level
|
||||||
We have Scheme implementations for the ftp, telnet, smtp, finger, and
|
support scsh provides.
|
||||||
http protocols, as well as an html parser.
|
The Scheme Underground has also released a network library with
|
||||||
When this code is included in a future release, this chapter
|
many of these protocols as a companion to the current release of scsh.
|
||||||
will describe the interfaces.
|
See this code for examples showing the use of the sockets interface.
|
||||||
We are also contemplating a tail-recursive RPC mechanism,
|
|
||||||
but have done no development work.
|
|
||||||
|
|
||||||
\section{High-level interface}
|
\section{High-level interface}
|
||||||
|
|
||||||
For convenience, and too avoid some of the messy details of the socket
|
For convenience, and to avoid some of the messy details of the socket
|
||||||
interface, we provide a high level socket interface. These routines
|
interface, we provide a high level socket interface. These routines
|
||||||
attempt to make it easy to write simple clients and servers without
|
attempt to make it easy to write simple clients and servers without
|
||||||
having to think of many of the details of initiating socket connections.
|
having to think of many of the details of initiating socket connections.
|
||||||
We welcome suggested improvements to this interface, including better
|
We welcome suggested improvements to this interface, including better
|
||||||
names, which right now are solely descriptions of the procedure's action..
|
names, which right now are solely descriptions of the procedure's action.
|
||||||
This might be fine for people who already understand sockets,
|
This might be fine for people who already understand sockets,
|
||||||
but does not help the new networking programmer.
|
but does not help the new networking programmer.
|
||||||
|
|
||||||
|
|
@ -184,8 +182,7 @@ than an empty string for addresses in the {\Unix} address-family.
|
||||||
|
|
||||||
The procedures in this section are presented in the order in which a
|
The procedures in this section are presented in the order in which a
|
||||||
typical program will use them. Consult a text on network systems
|
typical program will use them. Consult a text on network systems
|
||||||
programming for more information on sockets.
|
programming for more information on sockets.\footnote{
|
||||||
\footnote{
|
|
||||||
Some recommended ones are:
|
Some recommended ones are:
|
||||||
|
|
||||||
\begin{itemize}
|
\begin{itemize}
|
||||||
|
|
@ -273,12 +270,18 @@ shutdown/sends+receives\end{code}
|
||||||
\section{Performing input and output on sockets}
|
\section{Performing input and output on sockets}
|
||||||
|
|
||||||
\defun {receive-message} {socket length [flags]} {[string-or-\sharpf socket-address]}
|
\defun {receive-message} {socket length [flags]} {[string-or-\sharpf socket-address]}
|
||||||
\defunx {receive-message!} {socket string [start] [end] [flags]} {[count-or-\sharpf socket-address]}
|
\dfnix {receive-message!} {socket string [start] [end] [flags]}
|
||||||
\defunx {receive-message/partial} {socket length [flags]} {[string-or-\sharpf socket-address]}
|
{[count-or-\sharpf socket-address]}{procedure}
|
||||||
\defunx {receive-message!/partial} {socket string [start] [end] [flags]} {[count-or-\sharpf socket-address]}
|
{receive-message"!@\texttt{receive-message"!}}
|
||||||
|
\defunx {receive-message/partial} {socket length [flags]}
|
||||||
\defun {send-message} {socket string [start] [end] [flags] [socket-address]} \undefined
|
{[string-or-\sharpf socket-address]}
|
||||||
\defunx {send-message/partial} {socket string [start] [end] [flags] [socket-address]} {count}
|
\dfnix {receive-message!/partial} {socket string [start] [end] [flags]}
|
||||||
|
{[count-or-\sharpf socket-address]}{procedure}
|
||||||
|
{receive-message"!/partial@\texttt{receive-message"!/partial}}
|
||||||
|
\defun {send-message} {socket string [start] [end] [flags] [socket-address]}
|
||||||
|
\undefined
|
||||||
|
\defunx {send-message/partial}
|
||||||
|
{socket string [start] [end] [flags] [socket-address]} {count}
|
||||||
|
|
||||||
\begin{desc}
|
\begin{desc}
|
||||||
For most uses, standard input and output routines such as
|
For most uses, standard input and output routines such as
|
||||||
|
|
|
||||||
|
|
@ -105,7 +105,7 @@ It is equivalent to the three redirections:
|
||||||
(= 2 ,(error-output-port))\end{code}
|
(= 2 ,(error-output-port))\end{code}
|
||||||
%
|
%
|
||||||
The redirections are done in the indicated order. This will cause an error if
|
The redirections are done in the indicated order. This will cause an error if
|
||||||
the one of current i/o ports isn't a {\Unix} port (\eg, if one is a string
|
one of the current i/o ports isn't a {\Unix} port (\eg, if one is a string
|
||||||
port).
|
port).
|
||||||
This {\Scheme}/{\Unix} i/o synchronisation can also be had in {\Scheme} code
|
This {\Scheme}/{\Unix} i/o synchronisation can also be had in {\Scheme} code
|
||||||
(as opposed to a redirection spec) with the \ex{(stdports->stdio)}
|
(as opposed to a redirection spec) with the \ex{(stdports->stdio)}
|
||||||
|
|
@ -169,6 +169,11 @@ The second clause \ex{(3 1)} causes \vari{pf}{\!1}'s file descriptor 3 to be
|
||||||
connected to \vari{pf}{\!2}'s file descriptor 1.
|
connected to \vari{pf}{\!2}'s file descriptor 1.
|
||||||
%---this is unusual, and not expected to occur very often.
|
%---this is unusual, and not expected to occur very often.
|
||||||
|
|
||||||
|
The \ex{begin} process form does a \ex{stdio->stdports} synchronisation
|
||||||
|
in the child process before executing the body of the form.
|
||||||
|
This guarantees that the \ex{begin} form, like all other process forms,
|
||||||
|
``sees'' the effects of any associated I/O redirections.
|
||||||
|
|
||||||
Note that {\R4RS} does not specify whether or not \ex{|} and \ex{|+}
|
Note that {\R4RS} does not specify whether or not \ex{|} and \ex{|+}
|
||||||
are readable symbols. Scsh does.
|
are readable symbols. Scsh does.
|
||||||
|
|
||||||
|
|
@ -185,12 +190,13 @@ There are three basic {\Scheme} forms that use extended process forms:
|
||||||
\dfnx {\&} {. \var{epf}} {\integer} {syntax}
|
\dfnx {\&} {. \var{epf}} {\integer} {syntax}
|
||||||
\dfnx {run} {. \var{epf}} {\integer} {syntax}
|
\dfnx {run} {. \var{epf}} {\integer} {syntax}
|
||||||
\begin{desc}
|
\begin{desc}
|
||||||
|
\index{exec-epf} \index{\&} \index{run}
|
||||||
The \ex{(exec-epf . \var{epf})} form nukes the current process: it establishes
|
The \ex{(exec-epf . \var{epf})} form nukes the current process: it establishes
|
||||||
the i/o redirections and then overlays the current process with the requested
|
the i/o redirections and then overlays the current process with the requested
|
||||||
computation.
|
computation.
|
||||||
|
|
||||||
The \ex{(\& . \var{epf})} form is similar, except that the process is forked
|
The \ex{(\& . \var{epf})} form is similar, except that the process is forked
|
||||||
off in background. The form returns the subprocess' pid.
|
off in background. The form returns the subprocess' process object.
|
||||||
|
|
||||||
The \ex{(run . \var{epf})} form runs the process in foreground:
|
The \ex{(run . \var{epf})} form runs the process in foreground:
|
||||||
after forking off the computation, it waits for the subprocess to exit,
|
after forking off the computation, it waits for the subprocess to exit,
|
||||||
|
|
@ -235,7 +241,7 @@ Having a solid procedural foundation also allows for general notational
|
||||||
experimentation using {\Scheme}'s macros.
|
experimentation using {\Scheme}'s macros.
|
||||||
For example, the programmer can build his own pipeline notation on top of the
|
For example, the programmer can build his own pipeline notation on top of the
|
||||||
\ex{fork} and \ex{fork/pipe} procedures.
|
\ex{fork} and \ex{fork/pipe} procedures.
|
||||||
Chapter~\ref{chapter:syscalls} gives the full story on all the procedures
|
Chapter~\ref{chapt:syscalls} gives the full story on all the procedures
|
||||||
in the syscall library.
|
in the syscall library.
|
||||||
|
|
||||||
\subsection{Interfacing process output to {\Scheme}}
|
\subsection{Interfacing process output to {\Scheme}}
|
||||||
|
|
@ -349,23 +355,27 @@ for manipulating processes.
|
||||||
|
|
||||||
|
|
||||||
\subsection{Pids and ports together}
|
\subsection{Pids and ports together}
|
||||||
\dfn {run/port+pid} {. \var{epf}} {[port fixnum]} {syntax}
|
\dfn {run/port+proc} {. \var{epf}} {[port proc]} {syntax}
|
||||||
\defunx {run/port+pid*} {thunk} {[port fixnum]}
|
\defunx {run/port+proc*} {thunk} {[port proc]}
|
||||||
\begin{desc}
|
\begin{desc}
|
||||||
This special form and its analogous procedure can be used
|
This special form and its analogous procedure can be used
|
||||||
if the programmer also wishes access to the process' pid, exit status,
|
if the programmer also wishes access to the process' pid, exit status,
|
||||||
or other information.
|
or other information.
|
||||||
They both fork off a subprocess, returning two values:
|
They both fork off a subprocess, returning two values:
|
||||||
a port open on the process' stdout, and the subprocess's pid.
|
a port open on the process' stdout (and current output port),
|
||||||
|
and the subprocess's process object.
|
||||||
|
A process object encapsulates the subprocess' process id and exit code;
|
||||||
|
it is the value passed to the \ex{wait} system call.
|
||||||
|
|
||||||
|
|
||||||
For example, to uncompress a tech report, reading the uncompressed
|
For example, to uncompress a tech report, reading the uncompressed
|
||||||
data into scsh, and also be able to track the exit status of
|
data into scsh, and also be able to track the exit status of
|
||||||
the decompression process, use the following:
|
the decompression process, use the following:
|
||||||
\begin{code}
|
\begin{code}
|
||||||
(receive (port pid) (run/port+pid (zcat tr91-145.tex.Z))
|
(receive (port child) (run/port+proc (zcat tr91-145.tex.Z))
|
||||||
(let* ((paper (port->string port))
|
(let* ((paper (port->string port))
|
||||||
(status (wait pid)))
|
(status (wait child)))
|
||||||
{\rm\ldots{}use \ex{paper}, \ex{status}, and \ex{pid} here\ldots}))\end{code}
|
{\rm\ldots{}use \ex{paper}, \ex{status}, and \ex{child} here\ldots}))\end{code}
|
||||||
%
|
%
|
||||||
Note that you must \emph{first} do the \ex{port->string} and
|
Note that you must \emph{first} do the \ex{port->string} and
|
||||||
\emph{then} do the wait---the other way around may lock up when the
|
\emph{then} do the wait---the other way around may lock up when the
|
||||||
|
|
|
||||||
|
|
@ -0,0 +1,139 @@
|
||||||
|
%&latex -*- latex -*-
|
||||||
|
|
||||||
|
\chapter{Reading delimited strings}
|
||||||
|
\label{chapt:rdelim}
|
||||||
|
|
||||||
|
Scsh provides a set of procedures that read delimited strings from
|
||||||
|
input ports.
|
||||||
|
There are procedures to read a single line of text
|
||||||
|
(terminated by a newline character),
|
||||||
|
a single paragraph (terminated by a blank line),
|
||||||
|
and general delimited strings
|
||||||
|
(terminated by a character belonging to an arbitrary character set).
|
||||||
|
|
||||||
|
These procedures can be applied to any Scheme input port.
|
||||||
|
However, the scsh virtual machine has native-code support for performing
|
||||||
|
delimited reads on Unix ports, and these input operations should be
|
||||||
|
particularly fast---much faster than doing the equivalent character-at-a-time
|
||||||
|
operation from Scheme code.
|
||||||
|
|
||||||
|
All of the delimited input operations described below take a \ex{handle-delim}
|
||||||
|
parameter, which determines what the procedure does with the terminating
|
||||||
|
delimiter character.
|
||||||
|
There are four possible choices for a \ex{handle-delim} parameter:
|
||||||
|
\begin{inset}
|
||||||
|
\begin{tabular}{|l|l|} \hline
|
||||||
|
\ex{handle-delim} & Meaning \\ \hline\hline
|
||||||
|
\ex{'trim} & Ignore delimiter character. \\
|
||||||
|
\ex{'peek} & Leave delimiter character in input stream. \\
|
||||||
|
\ex{'concat} & Append delimiter character to returned value. \\
|
||||||
|
\ex{'split} & Return delimiter as second value. \\
|
||||||
|
\hline
|
||||||
|
\end{tabular}
|
||||||
|
\end{inset}
|
||||||
|
The last three cases allow the programmer to distinguish between strings
|
||||||
|
that are terminated by a delimiter character, and strings that are
|
||||||
|
terminated by an end-of-file.
|
||||||
|
|
||||||
|
|
||||||
|
\begin{defundesc} {read-line} {[port handle-newline]} {{\str} or eof-object}
|
||||||
|
Reads and returns one line of text; on eof, returns the eof object.
|
||||||
|
A line is terminated by newline or eof.
|
||||||
|
|
||||||
|
\var{handle-newline} determines what \ex{read-line} does with the
|
||||||
|
newline or EOF that terminates the line; it takes the general set
|
||||||
|
of values described for the general \ex{handle-delim} case above,
|
||||||
|
and defaults to \ex{'trim} (discard the newline).
|
||||||
|
Using this argument allows one to tell whether or not the last line of
|
||||||
|
input in a file is newline terminated.
|
||||||
|
\end{defundesc}
|
||||||
|
|
||||||
|
\defun{read-paragraph} {[port handle-delim]} {{\str} or eof}
|
||||||
|
\begin{desc}
|
||||||
|
This procedure skips blank lines,
|
||||||
|
then reads text from a port until a blank line or eof is found.
|
||||||
|
A ``blank line'' is a (possibly empty) line composed only of white space.
|
||||||
|
The \var{handle-delim} parameter determines how the terminating
|
||||||
|
blank line is handled.
|
||||||
|
It is described above, and defaults to \ex{'trim}.
|
||||||
|
The \ex{'peek} option is not available.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
|
||||||
|
The following procedures read in strings from ports delimited by characters
|
||||||
|
belonging to a specific set.
|
||||||
|
See section~\ref{sec:char-sets} for information on character set manipulation.
|
||||||
|
|
||||||
|
\defun{read-delimited}{char-set [port handle-delim]} {{\str} or eof}
|
||||||
|
\begin{desc}
|
||||||
|
Read until we encounter one of the chars in \var{char-set} or eof.
|
||||||
|
The \var{handle-delim} parameter determines how the terminating character
|
||||||
|
is handled. It is described above, and defaults to \ex{'peek}.
|
||||||
|
|
||||||
|
The \var{char-set} argument may be a charset, a string, a character, or a
|
||||||
|
character predicate; it is coerced to a charset.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
\dfni{read-delimited!} {char-set buf [port handle-delim start end]}
|
||||||
|
{nchars or eof or \#f}{procedure}
|
||||||
|
{read-delimited"!@\texttt{read-delimited"!}}
|
||||||
|
\begin{desc}
|
||||||
|
A side-effecting variant of \ex{read-delimited}.
|
||||||
|
|
||||||
|
The data is written into the string \var{buf} at the indices in the
|
||||||
|
half-open interval $[\var{start},\var{end})$; the default interval is the
|
||||||
|
whole string: $\var{start}=0$ and $\var{end}=\ex{(string-length
|
||||||
|
\var{buf})}$. The values of \var{start} and \var{end} must specify a
|
||||||
|
well-defined interval in \var{str}, \ie, $0 \le \var{start} \le \var{end}
|
||||||
|
\le \ex{(string-length \var{buf})}$.
|
||||||
|
|
||||||
|
It returns \var{nbytes}, the number of bytes read. If the buffer filled up
|
||||||
|
without a delimiter character being found, \ex{\#f} is returned. If
|
||||||
|
the port is at eof when the read starts, the eof object is returned.
|
||||||
|
|
||||||
|
If an integer is returned (\ie, the read is successfully terminated by
|
||||||
|
reading a delimiter character), then the \var{handle-delim} parameter
|
||||||
|
determines how the terminating character is handled.
|
||||||
|
It is described above, and defaults to \ex{'peek}.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
\dfni{\%read-delimited!} {char-set buf gobble? [port start end]}
|
||||||
|
{[char-or-eof-or-\#f \integer]}{procedure}
|
||||||
|
{"%read-delimited"!@\verb:"%read-delimited"!:}
|
||||||
|
\begin{desc}
|
||||||
|
This low-level delimited reader uses an alternate interface.
|
||||||
|
It returns two values: \var{terminator} and \var{num-read}.
|
||||||
|
\begin{description}
|
||||||
|
\item [terminator]
|
||||||
|
A value describing why the read was terminated:
|
||||||
|
\begin{flushleft}
|
||||||
|
\begin{tabular}{l@{\qquad$\Rightarrow$\qquad}l}
|
||||||
|
Character or eof-object & Read terminated by this value. \\
|
||||||
|
\ex{\#f} & Filled buffer without finding a delimiter.
|
||||||
|
\end{tabular}
|
||||||
|
\end{flushleft}
|
||||||
|
|
||||||
|
\item [num-read]
|
||||||
|
Number of characters read into \var{buf}.
|
||||||
|
\end{description}
|
||||||
|
|
||||||
|
If the read is successfully terminated by reading a delimiter character,
|
||||||
|
then the \var{gobble?} parameter determines what to do with the terminating
|
||||||
|
character.
|
||||||
|
If true, the character is removed from the input stream;
|
||||||
|
if false, the character is left in the input stream where a subsequent
|
||||||
|
read operation will retrieve it.
|
||||||
|
In either case, the character is also the first value returned by
|
||||||
|
the procedure call.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
%Note:
|
||||||
|
%- Invariant: TERMINATOR = #f => NUM-READ = END - START.
|
||||||
|
%- Invariant: TERMINATOR = eof-object and NUM-READ = 0 => at EOF.
|
||||||
|
%- When determining the TERMINATOR return value, ties are broken
|
||||||
|
% favoring character or the eof-object over #f. That is, if the buffer
|
||||||
|
% fills up, %READ-DELIMITED! will peek at one more character from the
|
||||||
|
% input stream to determine if it terminates the input. If so, that
|
||||||
|
% is returned, not #f.
|
||||||
|
|
@ -1,47 +1,621 @@
|
||||||
%&latex -*- latex -*-
|
%&latex -*- latex -*-
|
||||||
|
|
||||||
\chapter{Running scsh}
|
\chapter{Running scsh}
|
||||||
|
\label{chapt:running}
|
||||||
|
|
||||||
Scsh is currently implemented on top of {\scm}, a freely-available
|
Scsh is currently implemented on top of {\scm}, a freely-available
|
||||||
{\Scheme} implementation written by Jonathan Rees and Richard Kelsey.
|
{\Scheme} implementation written by Jonathan Rees and Richard Kelsey.
|
||||||
{\scm} uses a byte-code interpreter for good code density, portability
|
{\scm} uses a byte-code interpreter for good code density, portability
|
||||||
and medium efficiency. It is {\R4RS}. The version on top of which scsh is
|
and medium efficiency. It is {\R4RS}.
|
||||||
currently built (0.36) lacks floating point.
|
|
||||||
It also has a module system designed by Jonathan Rees.
|
It also has a module system designed by Jonathan Rees.
|
||||||
|
|
||||||
Scsh's design is not {\scm} specific, although the current implementation
|
Scsh's design is not {\scm} specific, although the current implementation
|
||||||
is necessarily so. Scsh is intended to be implementable in other {\Scheme}
|
is necessarily so.
|
||||||
implementations---although such a port may require some work.
|
Scsh is intended to be implementable in other {\Scheme} implementations.
|
||||||
The {\scm} vm that scsh uses is a specially modified version;
|
The {\scm} virtual machine that scsh uses is a specially modified version;
|
||||||
standard {\scm} virtual machines cannot be used with the scsh heap image.
|
standard {\scm} virtual machines cannot be used with the scsh heap image.
|
||||||
|
|
||||||
|
There are several different ways to invoke scsh.
|
||||||
|
You can run it as an interactive Scheme system, with a standard
|
||||||
|
read-eval-print interaction loop.
|
||||||
|
Scsh can also be invoked as the interpreter for a shell script by putting
|
||||||
|
a ``\verb|#!/usr/local/bin/scsh -s|'' line at the top of the shell script.
|
||||||
|
|
||||||
|
Descending a level, it is also possible to invoke the underlying virtual
|
||||||
|
machine byte-code interpreter directly on dumped heap images.
|
||||||
|
Scsh programs can be pre-compiled to byte-codes and dumped as raw,
|
||||||
|
binary heap images.
|
||||||
|
Writing heap images strips out unused portions of the scsh runtime
|
||||||
|
(such as the compiler, the debugger, and other complex subsystems),
|
||||||
|
reducing memory demands and saving loading and compilation times.
|
||||||
|
The heap image format allows for an initial \verb|#!/usr/local/lib/scsh/scshvm| trigger
|
||||||
|
on the first line of the image, making heap images directly executable as
|
||||||
|
another kind of shell script.
|
||||||
|
|
||||||
|
Finally, scsh's static linker system allows dumped heap images to be compiled
|
||||||
|
to a raw Unix a.out(5) format, which can be linked into the text section
|
||||||
|
of the vm binary.
|
||||||
|
This produces a true Unix executable binary file.
|
||||||
|
Since the byte codes comprising the program are in the file's text section,
|
||||||
|
they are not traced or copied by the garbage collector, do not occupy space
|
||||||
|
in the vm's heap, and do not need to be loaded and linked at startup time.
|
||||||
|
This reduces the program's startup time, memory requirements,
|
||||||
|
and paging overhead.
|
||||||
|
|
||||||
|
This chapter will cover these various ways of invoking scsh programs.
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
\section{Scsh command-line switches}
|
||||||
|
|
||||||
|
When the scsh top-level starts up, it scans the command line
|
||||||
|
for switches that control its behaviour.
|
||||||
|
These arguments are removed from the command line;
|
||||||
|
the remaining arguments can be accessed as the value of
|
||||||
|
the scsh variable \ex{command-line-arguments}.
|
||||||
|
|
||||||
|
\subsection{Scripts and programs}
|
||||||
|
|
||||||
|
The scsh command-line switches provide sophisticated support for
|
||||||
|
the authors of shell scripts and programs;
|
||||||
|
they also allow the programmer to write programs
|
||||||
|
that use the {\scm} module system.
|
||||||
|
|
||||||
|
There is a difference between a \emph{script}, which performs its action
|
||||||
|
\emph{as it is loaded}, and a \emph{program}, which is loaded/linked,
|
||||||
|
and then performs its action by having control transferred to an entry point
|
||||||
|
(\eg, the \ex{main()} function in C programs) that was defined by the
|
||||||
|
load/link operation.
|
||||||
|
|
||||||
|
A \emph{script}, by the above definition, cannot be compiled by the simple
|
||||||
|
mechanism of loading it into a scsh process and dumping out a heap image---it
|
||||||
|
executes as it loads. It does not have a top-level \ex{main()}-type entry
|
||||||
|
point.
|
||||||
|
|
||||||
|
It is more flexible and useful to implement a system
|
||||||
|
as a program than as a script.
|
||||||
|
Programs can be compiled straightforwardly;
|
||||||
|
they can also export procedural interfaces for use by other Scheme packages.
|
||||||
|
However, scsh supports both the script and the program style of programming.
|
||||||
|
|
||||||
|
\subsection{Inserting interpreter triggers into scsh programs}
|
||||||
|
When Unix tries to execute an executable file whose first 16 bits are
|
||||||
|
the character pair ``\ex{\#!}'', it treats the file not as machine-code
|
||||||
|
to be directly executed by the native processor, but as source code to
|
||||||
|
be executed by some interpreter.
|
||||||
|
The interpreter to use is specified immediately after the ``\ex{\#!}''
|
||||||
|
sequence on the first line of the source file
|
||||||
|
(along with one optional initial argument).
|
||||||
|
The kernel reads in the name of the interpreter, and executes that instead.
|
||||||
|
The interpreter is passed the source filename as its first argument, with
|
||||||
|
the original arguments following.
|
||||||
|
Consult the Unix man page for the \ex{exec} system call for more information.
|
||||||
|
|
||||||
|
Scsh allows Scheme programs to have these triggers placed on
|
||||||
|
their first line.
|
||||||
|
Scsh treats the character sequence ``\ex{\#!}'' as a block-comment sequence,%
|
||||||
|
\footnote{Why a block-comment instead of an end-of-line delimited comment?
|
||||||
|
See the section on meta-args.}
|
||||||
|
and skips all following characters until it reads the comment-terminating
|
||||||
|
sequence newline/exclamation-point/sharp-sign/newline (\ie, the
|
||||||
|
sequence ``\ex{!\#}'' occurring on its own line).
|
||||||
|
|
||||||
|
In this way, the programmer can arrange for an initial
|
||||||
|
\begin{code}
|
||||||
|
#!/usr/local/bin/scsh -s
|
||||||
|
!#\end{code}
|
||||||
|
header appearing in a Scheme program
|
||||||
|
to be ignored when the program is loaded into scsh.
|
||||||
|
|
||||||
|
\subsection{Module system}
|
||||||
|
Scsh uses the {\scm} module system, which defines
|
||||||
|
\emph{packages}, \emph{structures}, and \emph{interfaces}.
|
||||||
|
%
|
||||||
|
\begin{description}
|
||||||
|
|
||||||
|
\item [Package] A package is an environment---that is, a set of
|
||||||
|
variable/value bindings.
|
||||||
|
You can evaluate Scheme forms inside a package, or load a file into a package.
|
||||||
|
Packages export sets of bindings; these sets are called \emph{structures}.
|
||||||
|
|
||||||
|
\item [Structure] A structure is a named view on a package---a set of
|
||||||
|
bindings. Other packages can \emph{open} the structure, importing its
|
||||||
|
bindings into their environment. Packages can provide more than one
|
||||||
|
structure, revealing different portions of the package's environment.
|
||||||
|
|
||||||
|
\item [Interface] An interface is the ``type'' of a structure. An
|
||||||
|
interface is the set of names exported by a structure. These names
|
||||||
|
can also be marked with other static information (\eg, advisory type
|
||||||
|
declarations, or syntax information).
|
||||||
|
\end{description}
|
||||||
|
More information on the the {\scm} module system can be found in the
|
||||||
|
file \ex{module.ps} in the \ex{doc} directory of the {\scm} and scsh releases.
|
||||||
|
|
||||||
|
Programming Scheme with a module system is different from programming
|
||||||
|
in older Scheme implementations,
|
||||||
|
and the associated development problems are consequently different.
|
||||||
|
In Schemes that lack modular abstraction mechanisms,
|
||||||
|
everything is accessible; the major problem is preventing name-space conflicts.
|
||||||
|
In Scheme 48, name-space conflicts vanish; the major problem is that not
|
||||||
|
all bindings are accessible from every place.
|
||||||
|
It takes a little extra work to specify what packages export which values.
|
||||||
|
|
||||||
|
It may take you a little while to get used to the new style of program
|
||||||
|
development.
|
||||||
|
Although scsh can be used without referring to the module system at
|
||||||
|
all, we recommend taking the time to learn and use it.
|
||||||
|
The effort will pay off in the construction of modular, factorable programs.
|
||||||
|
|
||||||
|
\subsection{Switches}
|
||||||
|
\label{sec:scsh-switches}
|
||||||
|
The scsh top-level takes command-line switches in the following format:
|
||||||
|
%
|
||||||
|
\codex{scsh [\var{meta-arg}] [\vari{switch}i {\ldots}]
|
||||||
|
[\var{end-option} \vari{arg}1 {\ldots} \vari{arg}n]}
|
||||||
|
where
|
||||||
|
\begin{inset}
|
||||||
|
\begin{flushleft}
|
||||||
|
\begin{tabular}{ll@{\qquad}l}
|
||||||
|
\var{meta-arg:} & \verb|\| \var{script-file-name} \\
|
||||||
|
\\
|
||||||
|
\var{switch:} & \ex{-e} \var{entry-point}
|
||||||
|
& Specify top-level entry-point. \\
|
||||||
|
|
||||||
|
& \ex{-o} \var{structure}
|
||||||
|
& Open structure in current package. \\
|
||||||
|
|
||||||
|
& \ex{-m} \var{structure}
|
||||||
|
& Switch to package. \\
|
||||||
|
|
||||||
|
& \ex{-n} \var{new-package}
|
||||||
|
& Switch to new package. \\ \\
|
||||||
|
|
||||||
|
|
||||||
|
& \ex{-lm} \var{module-file-name}
|
||||||
|
& Load module into config package. \\
|
||||||
|
|
||||||
|
& \ex{-l} \var{file-name}
|
||||||
|
& Load file into current package. \\
|
||||||
|
|
||||||
|
|
||||||
|
& \ex{-dm} & Do script module. \\
|
||||||
|
& \ex{-ds} & Do script. \\
|
||||||
|
\\
|
||||||
|
\var{end-option:} & \ex{-s} \var{script} \\
|
||||||
|
& \ex{-c} \var{exp} \\
|
||||||
|
& \ex{--}
|
||||||
|
\end{tabular}
|
||||||
|
\end{flushleft}
|
||||||
|
\end{inset}
|
||||||
|
%
|
||||||
|
These command-line switches
|
||||||
|
essentially provide a little linker language for linking a shell script or a
|
||||||
|
program together with {\scm} modules.
|
||||||
|
The command-line processor serially opens structures and loads code into a
|
||||||
|
given package.
|
||||||
|
Switches that side-effect a package operate on a particular ``current''
|
||||||
|
package; there are switches to change this package.
|
||||||
|
(These switches provide functionality equivalent to the interactive
|
||||||
|
\ex{,open} \ex{,load} \ex{,in} and \ex{,new} commands.)
|
||||||
|
Except where indicated, switches specify actions that are executed in a
|
||||||
|
left-to-right order.
|
||||||
|
The initial current package is the user package, which is completely
|
||||||
|
empty and opens (imports the bindings of) the R4RS and scsh structures.
|
||||||
|
|
||||||
|
If the Scheme process is started up in an interactive mode, then the current
|
||||||
|
package in force at the end of switch scanning is the one inside which
|
||||||
|
the interactive read-eval-print loop is started.
|
||||||
|
|
||||||
|
The command-line switch processor works in two passes:
|
||||||
|
it first parses the switches, building a list of actions to perform,
|
||||||
|
then the actions are performed serially.
|
||||||
|
The switch list is terminated by one of the \var{end-option} switches.
|
||||||
|
The \vari{arg}{i} arguments occurring after an end-option switch are
|
||||||
|
passed to the scsh program as the value of \ex{command-line-arguments}
|
||||||
|
and the tail of the list returned by \ex{(command-line)}.
|
||||||
|
That is, an \var{end-option} switch separates switches that control
|
||||||
|
the scsh ``machine'' from the actual arguments being passed to the scsh
|
||||||
|
program that runs on that machine.
|
||||||
|
|
||||||
|
The following switches and end options are defined:
|
||||||
|
\begin{itemize}
|
||||||
|
\def\Item#1{\item{\ex{#1}}\\}
|
||||||
|
|
||||||
|
\Item{-o \var{struct}}
|
||||||
|
Open the structure in the current package.
|
||||||
|
|
||||||
|
\Item{-n \var{package}}
|
||||||
|
Make and enter a new package. The package has an associated structure
|
||||||
|
named \var{package} with an empty export list.
|
||||||
|
If \var{package} is the string ``\ex{\#f}'',
|
||||||
|
the new package is anonmyous, with no associated named structure.
|
||||||
|
|
||||||
|
The new package initially opens no other structures,
|
||||||
|
not even the R4RS bindings. You must follow a ``\ex{-n foo}''
|
||||||
|
switch with ``\ex{-o scheme}'' to access the standard identifiers such
|
||||||
|
as \ex{car} and \ex{define}.
|
||||||
|
|
||||||
|
\Item{-m \var{struct}}
|
||||||
|
Change the current package to the package underlying
|
||||||
|
structure \var{struct}.
|
||||||
|
(The \ex{-m} stands for ``module.'')
|
||||||
|
|
||||||
|
\Item{-lm \var{module-file-name}}
|
||||||
|
Load the specified file into scsh's config package --- the file
|
||||||
|
must contain source written in the Scheme 48 module language
|
||||||
|
(``load module''). Does not alter the current package.
|
||||||
|
|
||||||
|
\Item{-l \var{file-name}}
|
||||||
|
Load the specified file into the current package.
|
||||||
|
|
||||||
|
\Item{-c \var{exp}}
|
||||||
|
Evaluate expression \var{exp} in the current package and exit.
|
||||||
|
This is called \ex{-c} after a common shell convention (see sh and csh).
|
||||||
|
The expression is evaluated in the the current package (and hence is
|
||||||
|
affected by \ex{-m}'s and \ex{-n}'s.)
|
||||||
|
|
||||||
|
When the scsh top-level constructs the scsh command-line in this case,
|
||||||
|
it takes \ex{"scsh"} to be the program name.
|
||||||
|
This switch terminates argument scanning; following args become
|
||||||
|
the tail of the command-line list.
|
||||||
|
|
||||||
|
\Item{-e \var{entry-point}}
|
||||||
|
Specify an entry point for a program. The \var{entry-point} is
|
||||||
|
a variable that is taken from the current package in force at the end
|
||||||
|
of switch evaluation. The entry point does not have to be exported
|
||||||
|
by the package in a structure; it can be internal to the package.
|
||||||
|
The top level passes control to the entry point by applying it to
|
||||||
|
the command-line list (so programs executing in private
|
||||||
|
packages can reference their command-line arguments without opening
|
||||||
|
the \ex{scsh} package to access the \ex{(command-line)} procedure).
|
||||||
|
Note that, like the list returned by the \ex{(command-line)} procedure,
|
||||||
|
the list passed to the entry point includes the name
|
||||||
|
of the program being executed (as the first element of the list),
|
||||||
|
not just the arguments to the program.
|
||||||
|
|
||||||
|
A \ex{-e} switch can occur anywhere in the switch list, but it is the
|
||||||
|
\emph{last} action performed by switch scanning if it occurs.
|
||||||
|
(We violate ordering here as the shell-script \ex{\#!} mechanism
|
||||||
|
prevents you from putting the \emph{-e} switch last, where it belongs.)
|
||||||
|
|
||||||
|
\Item{-s \var{script}}
|
||||||
|
Specify a file to load.
|
||||||
|
A \ex{-ds} (do-script) or \ex{-dm} (do-module) switch occurring earlier in
|
||||||
|
the switch list gives the place where the script should be loaded. If
|
||||||
|
there is no \ex{-ds} or \ex{-dm} switch, then the script is loaded at the
|
||||||
|
end of switch scanning, into the module that is current at the end of
|
||||||
|
switch scanning.
|
||||||
|
|
||||||
|
We use the \ex{-ds} switch to violate left-to-right switch execution order
|
||||||
|
as the \ex{-s} switch is \emph{required} to be last
|
||||||
|
(because of the \ex{\#!} machinery),
|
||||||
|
independent of when/where in the switch-processing order
|
||||||
|
it should be loaded.
|
||||||
|
|
||||||
|
When the scsh top-level constructs the scsh command-line in this case,
|
||||||
|
it takes \var{script} to be the program name.
|
||||||
|
This switch terminates switch parsing; following args are ignored
|
||||||
|
by the switch-scanner and are passed through to the program as
|
||||||
|
the tail of the command-line list.
|
||||||
|
|
||||||
|
\Item{--}
|
||||||
|
Terminate argument scanning and start up scsh in interactive mode.
|
||||||
|
If the argument list just runs out, without either a terminating
|
||||||
|
\ex{-s} or \ex{--} arg, then scsh also starts up in interactive mode,
|
||||||
|
with an empty \ex{command-line-arguments} list
|
||||||
|
(for example, simply entering \ex{scsh} at a shell prompt with no
|
||||||
|
args at all).
|
||||||
|
|
||||||
|
When the scsh top-level constructs the scsh command-line in this case,
|
||||||
|
it takes \ex{"scsh"} to be the program name.
|
||||||
|
This switch terminates switch parsing; following args are ignored
|
||||||
|
by the switch-scanner and are passed through to the program as
|
||||||
|
the tail of the command-line list.
|
||||||
|
|
||||||
|
\Item{-ds}
|
||||||
|
Specify when to load the script (``do-script''). If this switch occurs,
|
||||||
|
the switch list \emph{must} be terminated by a \ex{-s \var{script}}
|
||||||
|
switch. The script is loaded into the package that is current at the
|
||||||
|
\ex{-ds} switch.
|
||||||
|
|
||||||
|
\Item{-dm}
|
||||||
|
As above, but the current module is ignored. The script is loaded into the
|
||||||
|
\ex{config} package (``do-module''), and hence must be written in the
|
||||||
|
{\scm} module language.
|
||||||
|
This switch doesn't affect the current module---after executing this
|
||||||
|
switch, the current module is the same as as it was before.
|
||||||
|
|
||||||
|
This switch is provided to make it easy to write shell scripts in the
|
||||||
|
{\scm} module language.
|
||||||
|
\end{itemize}
|
||||||
|
|
||||||
|
\subsection{The meta argument}
|
||||||
|
\label{sec:meta-arg}
|
||||||
|
The scsh switch parser takes a special command-line switch,
|
||||||
|
a single backslash called the ``meta-argument,'' which is useful for
|
||||||
|
shell scripts.
|
||||||
|
If the initial command-line argument is a ``\verb|\|''
|
||||||
|
argument, followed by a filename argument \var{fname}, scsh will open the file
|
||||||
|
\var{fname} and read more arguments from the second line of this file.
|
||||||
|
This list of arguments will then replace the ``\verb|\|'' argument---\ie,
|
||||||
|
the new arguments are inserted in front of \var{fname},
|
||||||
|
and the argument parser resumes argument scanning.
|
||||||
|
This is used to overcome a limitation of the \ex{\#!} feature:
|
||||||
|
the \ex{\#!} line can only specify a single argument after the interpreter.
|
||||||
|
For example, we might hope the following scsh script, \ex{ekko},
|
||||||
|
would implement a simple-minded version of the Unix \ex{echo} program:
|
||||||
|
\begin{code}
|
||||||
|
#!/usr/local/bin/scsh -e main -s
|
||||||
|
!#
|
||||||
|
(define (main args)
|
||||||
|
(map (\l{arg} (display arg) (display " "))
|
||||||
|
(cdr args))
|
||||||
|
(newline))\end{code}
|
||||||
|
%
|
||||||
|
The idea would be that the command
|
||||||
|
\codex{ekko Hi there.}
|
||||||
|
would by expanded by the \ex{exec(2)} kernel call into
|
||||||
|
%
|
||||||
|
\begin{code}
|
||||||
|
/usr/local/bin/scsh -e main -s ekko Hi there.\end{code}
|
||||||
|
%
|
||||||
|
In theory, this would cause scsh to start up, load in file \ex{ekko},
|
||||||
|
call the entry point on the command-line list
|
||||||
|
\codex{(main '("ekko" "Hi" "there."))}
|
||||||
|
and exit.
|
||||||
|
|
||||||
|
Unfortunately, the {\Unix} \ex{exec(2)} syscall's support for scripts is
|
||||||
|
not very general or well-designed.
|
||||||
|
It will not handle multiple arguments;
|
||||||
|
the \ex{\#!} line is usually required to contain no more than 32 characters;
|
||||||
|
it is not recursive.
|
||||||
|
If these restrictions are violated, most Unix systems will not provide accurate
|
||||||
|
error reporting, but either fail silently, or simply incorrectly implement
|
||||||
|
the desired functionality.
|
||||||
|
These are the facts of Unix life.
|
||||||
|
|
||||||
|
In the \ex{ekko} example above, our \ex{\#!} trigger line has three
|
||||||
|
arguments (``\ex{-e}'', ``\ex{main}'', and ``\ex{-s}''), so it will not
|
||||||
|
work.
|
||||||
|
The meta-argument is how we work around this problem.
|
||||||
|
We must instead invoke the scsh interpreter with the single \cd{\\} argument,
|
||||||
|
and put the rest of the arguments on line two of the program.
|
||||||
|
Here's the correct program:
|
||||||
|
%
|
||||||
|
\begin{code}
|
||||||
|
#!/usr/local/bin/scsh \\
|
||||||
|
-e main -s
|
||||||
|
!#
|
||||||
|
(define (main args)
|
||||||
|
(map (\l{arg} (display arg) (display " "))
|
||||||
|
(cdr args))
|
||||||
|
(newline))\end{code}
|
||||||
|
%
|
||||||
|
Now, the invocation starts as
|
||||||
|
\codex{ekko Hi there.}
|
||||||
|
and is expanded by exec(2) into
|
||||||
|
\begin{code}
|
||||||
|
/usr/local/bin/scsh \\ ekko Hi there.\end{code}
|
||||||
|
When scsh starts up, it expands the ``\cd{\\}'' argument into the arguments
|
||||||
|
read from line two of \ex{ekko}, producing this argument list:
|
||||||
|
\begin{code}\cddollar
|
||||||
|
\underline{-e main -s ekko} Hi there.
|
||||||
|
$\uparrow$
|
||||||
|
{\rm{}Expanded from} \cd{\\} ekko\end{code}
|
||||||
|
%
|
||||||
|
With this argument list, processing proceeds as we intended.
|
||||||
|
|
||||||
|
\subsubsection{Secondary argument syntax}
|
||||||
|
Scsh uses a very simple grammar to encode the extra arguments on
|
||||||
|
the second line of the scsh script.
|
||||||
|
The only special characters are space, tab, newline, and backslash.
|
||||||
|
\begin{itemize}
|
||||||
|
\item Each space character terminates an argument.
|
||||||
|
This means that two spaces in a row introduce an empty-string argument.
|
||||||
|
|
||||||
|
\item The tab character is not permitted
|
||||||
|
(unless you quote it with the backslash character described below).
|
||||||
|
This is to prevent the insidious bug where you believe you have
|
||||||
|
six space characters, but you really have a tab character,
|
||||||
|
and \emph{vice-versa}.
|
||||||
|
|
||||||
|
\item The newline character terminates the sequence of arguments,
|
||||||
|
and will also terminate a final non-empty argument.
|
||||||
|
(However, a newline following a space does not introduce a final
|
||||||
|
empty-string argument; it only terminates the argument list.)
|
||||||
|
|
||||||
|
\item The backslash character is the escape character.
|
||||||
|
It escapes backslash, space, tab, and newline, turning off their
|
||||||
|
special functions, and allowing them to be included in arguments.
|
||||||
|
The {\Ansi} C escape sequences, such as \verb|\n| and \verb|\t| are
|
||||||
|
also supported; these also produce argument-constituents---\verb|\n|
|
||||||
|
doesn't act like a terminating newline.
|
||||||
|
The escape sequence \verb|\|\emph{nnn} for \emph{exactly} three
|
||||||
|
octal digits reads as the character whose {\Ascii} code is \emph{nnn}.
|
||||||
|
It is an error if backslash is followed by just one or two octal digits:
|
||||||
|
\verb|\3Q| is an error.
|
||||||
|
Octal escapes are always constituent chars.
|
||||||
|
Backslash followed by other chars is not allowed
|
||||||
|
(so we can extend the escape-code space later if we like).
|
||||||
|
\end{itemize}
|
||||||
|
|
||||||
|
You have to construct these line-two argument lines carefully.
|
||||||
|
In particular, beware of trailing spaces at the end of the line---they'll
|
||||||
|
give you extra trailing empty-string arguments.
|
||||||
|
Here's an example:
|
||||||
|
%
|
||||||
|
\begin{inset}
|
||||||
|
\begin{verbatim}
|
||||||
|
#!/bin/interpreter \
|
||||||
|
foo bar quux\ yow\end{verbatim}
|
||||||
|
\end{inset}
|
||||||
|
%
|
||||||
|
would produce the arguments
|
||||||
|
%
|
||||||
|
\codex{("foo" "bar" "" "quux yow")}
|
||||||
|
|
||||||
|
\subsection{Examples}
|
||||||
|
|
||||||
|
\begin{itemize}
|
||||||
|
\def\Item#1{\item{\ex{#1}}\\}
|
||||||
|
\def\progItem#1{\item{Program \ex{#1}}\\}
|
||||||
|
|
||||||
|
\Item{scsh -dm -m myprog -e top -s myprog.scm}
|
||||||
|
Load \ex{myprog.scm} into the \ex{config} package, then shift to the
|
||||||
|
\ex{myprog} package and call \ex{(top '("myprog.scm"))}, then exit.
|
||||||
|
This sort of invocation is typically used in \ex{\#!} script lines
|
||||||
|
(see below).
|
||||||
|
|
||||||
|
\Item{scsh -c '(display "Hello, world.")'}
|
||||||
|
A simple program.
|
||||||
|
|
||||||
|
\Item{scsh -o bigscheme}
|
||||||
|
Start up interactively in the user package after opening
|
||||||
|
structure \ex{bigscheme}.
|
||||||
|
|
||||||
|
\Item{scsh -o bigscheme -- Three args passed}
|
||||||
|
Start up interactively in the user package after opening \ex{bigscheme}.
|
||||||
|
The \ex{command-line-args} variable in the scsh package is bound to the
|
||||||
|
list \ex{("Three" "args" "passed")}, and the \ex{(command-line)}
|
||||||
|
procedure returns the list \ex{("scsh" "Three" "args" "passed")}.
|
||||||
|
|
||||||
|
|
||||||
|
\progItem{ekko}
|
||||||
|
This shell script, called \ex{ekko}, implements a version of
|
||||||
|
the Unix \ex{echo} program:
|
||||||
|
\begin{code}
|
||||||
|
#!/usr/local/bin/scsh -s
|
||||||
|
!#
|
||||||
|
(for-each (\l{arg} (display arg) (display " "))
|
||||||
|
command-line-args)\end{code}
|
||||||
|
|
||||||
|
Note this short program is an example of a \emph{script}---it
|
||||||
|
executes as it loads.
|
||||||
|
The Unix rule for executing \ex{\#!} shell scripts causes
|
||||||
|
\codex{ekko Hello, world.}
|
||||||
|
to expand as
|
||||||
|
\codex{/usr/local/bin/scsh -s ekko Hello, world.}
|
||||||
|
|
||||||
|
\progItem{ekko}
|
||||||
|
This is the same program, \emph{not} as a script.
|
||||||
|
Writing it this way makes it possible to compile the program
|
||||||
|
(and then, for instance, dump it out as a heap image).
|
||||||
|
%
|
||||||
|
\begin{code}
|
||||||
|
#!/usr/local/bin/scsh \\
|
||||||
|
-e top -s
|
||||||
|
!#
|
||||||
|
(define (top args)
|
||||||
|
(for-each (\l{arg} (display arg) (display " "))
|
||||||
|
(cdr args)))\end{code}
|
||||||
|
%
|
||||||
|
The \ex{exec(2)} expansion of the \ex{\#!} line together with
|
||||||
|
the scsh expansion of the ``\verb|\ ekko|'' meta-argument
|
||||||
|
(see section~\ref{sec:meta-arg}) gives the following command-line expansion:
|
||||||
|
\begin{code}
|
||||||
|
ekko Hello, world.
|
||||||
|
{\evalto} /usr/local/bin/scsh \\ ekko Hello, world.
|
||||||
|
{\evalto} /usr/local/bin/scsh -e top -s ekko Hello, world.\end{code}
|
||||||
|
|
||||||
|
\progItem{sort}
|
||||||
|
This is a program to replace the Unix \ex{sort} utility---sorting lines
|
||||||
|
read from stdin, and printing the results on stdout.
|
||||||
|
Note that the source code defines a general sorting package,
|
||||||
|
which is useful (1) as a Scheme module exporting sort procedures
|
||||||
|
to other Scheme code, and (2) as a standalone program invoked from
|
||||||
|
the \ex{top} procedure.
|
||||||
|
\begin{code}
|
||||||
|
#!/usr/local/bin/scsh \\
|
||||||
|
-dm -m sort-toplevel -e top -s
|
||||||
|
!#
|
||||||
|
|
||||||
|
;;; This is a sorting module. TOP procedure exports
|
||||||
|
;;; the functionality as a Unix program akin to sort(1).
|
||||||
|
(define-structures ((sort-struct (export sort-list
|
||||||
|
sort-vector!))
|
||||||
|
(sort-toplevel (export top)))
|
||||||
|
(open scheme)
|
||||||
|
|
||||||
|
(begin (define (sort-list elts <=) {\ldots})
|
||||||
|
(define (sort-vec! vec <=) {\ldots})
|
||||||
|
|
||||||
|
;; Parse the command line and
|
||||||
|
;; sort stdin to stdout.
|
||||||
|
(define (top args)
|
||||||
|
{\ldots})))\end{code}
|
||||||
|
|
||||||
|
The expansion below shows how the command-line scanner
|
||||||
|
(1) loads the config file \ex{sort} (written in the {\scm} module language),
|
||||||
|
(2) switches to the package underlying the \ex{sort-toplevel} structure,
|
||||||
|
(3) calls \ex{(top '("sort" "foo" "bar"))} in the package, and finally
|
||||||
|
(4) exits.
|
||||||
|
%
|
||||||
|
{\small
|
||||||
|
\begin{centercode}
|
||||||
|
sort foo bar
|
||||||
|
{\evalto} /usr/local/bin/scsh \\ sort foo bar
|
||||||
|
{\evalto} /usr/local/bin/scsh -dm -m sort-toplevel -e top -s sort foo bar\end{centercode}}
|
||||||
|
|
||||||
|
An alternate method would have used a \ex{-n -o sort-toplevel}
|
||||||
|
sequence of switches to specify a top-level package.
|
||||||
|
|
||||||
|
\end{itemize}
|
||||||
|
|
||||||
|
Note that the sort example can be compiled into a Unix program by
|
||||||
|
loading the file into an scsh process, and dumping a heap with top-level
|
||||||
|
\ex{top}. Even if we don't want to export the sort's functionality as a
|
||||||
|
subroutine library, it is still useful to write the sort program with the
|
||||||
|
module language. The command line design allows us to run this program as
|
||||||
|
either an interpreted script (given the \ex{\#!} args in the header) or as a
|
||||||
|
compiled heap image.
|
||||||
|
|
||||||
|
\subsection{Process exit values}
|
||||||
|
Scsh ignores the value produced by its top-level computation when determining
|
||||||
|
its exit status code.
|
||||||
|
If the top-level computation completed with no errors,
|
||||||
|
scsh dies with exit code 0.
|
||||||
|
For example, a scsh process whose top-level is specified by a \ex{-c \var{exp}}
|
||||||
|
or a \ex{-e \var{entry}} entry point ignores the value produced
|
||||||
|
by evaluating \var{exp} and calling \var{entry}, respectively.
|
||||||
|
If these computations terminate with no errors, the scsh process
|
||||||
|
exits with an exit code of 0.
|
||||||
|
|
||||||
|
To return a specific exit status, use the \ex{exit} procedure explicitly, \eg,
|
||||||
|
\codex{scsh -c "(exit (run (| (fmt) (mail shivers@lcs.mit.edu))))"}
|
||||||
|
|
||||||
|
|
||||||
|
\section{The scsh virtual machine}
|
||||||
To run the {\scm} implementation of scsh, you run a specially modified
|
To run the {\scm} implementation of scsh, you run a specially modified
|
||||||
copy of the {\scm} virtual machine with a scsh heap image.
|
copy of the {\scm} virtual machine with a scsh heap image.
|
||||||
This command starts the vm up with a 1Mword heap (split into two semispaces):
|
The scsh binary is actually nothing but a small cover program that invokes the
|
||||||
\codex{scshvm -o scshvm -h 1000000 -i scsh.image arg1 arg2 \ldots}
|
byte-code interpreter on the scsh heap image for you.
|
||||||
The vm peels off initial vm arguments
|
|
||||||
up to the \ex{-i} heap image argument, which terminates vm argument parsing.
|
|
||||||
The rest of the arguments are passed off to the scsh top-level.
|
|
||||||
Scsh's top-level removes scsh arguments; the rest show up as the value
|
|
||||||
of \ex{command-line-arguments}.
|
|
||||||
|
|
||||||
Alternatively, you can run the scsh top-level binary.
|
|
||||||
This is nothing but a small cover program that invokes the
|
|
||||||
scsh vm on the scsh heap image for you.
|
|
||||||
This allows you to simply start up an interactive scsh from a command
|
This allows you to simply start up an interactive scsh from a command
|
||||||
line, as well as write shell scripts that begin with the simple trigger
|
line, as well as write shell scripts that begin with the simple trigger
|
||||||
\codex{\#!/usr/local/bin/scsh -s}
|
\codex{\#!/usr/local/bin/scsh -s}
|
||||||
|
|
||||||
\section{VM arguments}
|
You can also directly execute the virtual machine,
|
||||||
|
which takes its own set of command-line switches..
|
||||||
|
For example,
|
||||||
|
this command starts the vm up with a 1Mword heap (split into two semispaces):
|
||||||
|
\codex{scshvm -o scshvm -h 1000000 -i scsh.image arg1 arg2 \ldots}
|
||||||
|
The vm peels off initial vm arguments
|
||||||
|
up to the \ex{-i} heap image argument, which terminates vm argument parsing.
|
||||||
|
The rest of the arguments are passed off to the scsh top-level.
|
||||||
|
Scsh's top-level removes scsh switches, as discussed in the previous section;
|
||||||
|
the rest show up as the value of \ex{command-line-arguments}.
|
||||||
|
|
||||||
|
Directly executing the vm can be useful to specify non-standard switches, or
|
||||||
|
invoke the virtual machine on special heap images, which can contain
|
||||||
|
pre-compiled scsh programs with their own top-level procedures.
|
||||||
|
|
||||||
|
\subsection{VM arguments}
|
||||||
\label{sec:vm-args}
|
\label{sec:vm-args}
|
||||||
|
|
||||||
Scsh uses a special version of the {\scm} virtual machine.
|
The vm takes arguments in the following form:
|
||||||
It takes arguments in the following form:
|
|
||||||
\codex{scshvm [\var{meta-arg}] [\var{vm-options}\+] [\var{end-option} \var{scheme-args}]}
|
\codex{scshvm [\var{meta-arg}] [\var{vm-options}\+] [\var{end-option} \var{scheme-args}]}
|
||||||
where
|
where
|
||||||
\begin{inset}
|
\begin{inset}
|
||||||
\begin{tabular}{ll}
|
\begin{tabular}{ll}
|
||||||
\var{meta-arg:} & \verb|\ |\var{script} \\
|
\var{meta-arg:} & \verb|\ |\var{filename} \\
|
||||||
\\
|
\\
|
||||||
\var{vm-option}: & \ex{-h }\var{heap-size-in-words} \\
|
\var{vm-option}: & \ex{-h }\var{heap-size-in-words} \\
|
||||||
& \ex{-s }\var{stack-size-in-words} \\
|
& \ex{-s }\var{stack-size-in-words} \\
|
||||||
|
|
@ -52,156 +626,128 @@ where
|
||||||
\end{tabular}
|
\end{tabular}
|
||||||
\end{inset}
|
\end{inset}
|
||||||
|
|
||||||
\subsection{The meta argument}
|
The vm's meta-switch ``\verb|\ |\var{filename}'' is handled the same
|
||||||
The {\scm} vm takes a special command-line switch, a single backslash called
|
as scsh's meta-switch, and serves the same purpose.
|
||||||
the ``meta-switch,'' which is useful for shell scripts.
|
|
||||||
While parsing the command-line arguments, if the vm sees a ``\verb|\|''
|
|
||||||
argument, followed by a filename argument \var{fname}, it will open the file
|
|
||||||
\var{fname}, and read more arguments from the second line of this file.
|
|
||||||
This list of arguments will then replace the ``\verb|\|'' argument---\ie,
|
|
||||||
the new arguments are inserted in front of \var{fname},
|
|
||||||
and the argument parser resumes argument scanning.
|
|
||||||
This is used to overcome a limitation of the \ex{\#!} feature:
|
|
||||||
the \ex{\#!} line can only specify a single argument after the interpreter.
|
|
||||||
For example, we might hope the following scsh script, \ex{ekko},
|
|
||||||
would implement a simple-minded version of \ex{echo(1)}:
|
|
||||||
\begin{code}
|
|
||||||
#!/bin/scshvm -o /bin/scshvm -i /lib/scsh.image -s
|
|
||||||
!#
|
|
||||||
(map (\l{arg} (display arg) (display " "))
|
|
||||||
command-line-arguments)
|
|
||||||
(newline)\end{code}
|
|
||||||
%
|
|
||||||
The idea would be that the command
|
|
||||||
\codex{ekko Hi there.}
|
|
||||||
would by expanded by \ex{exec(2)} into
|
|
||||||
%
|
|
||||||
\begin{code}
|
|
||||||
/bin/scshvm -o /bin/scshvm -i /lib/scsh.image -s ekko Hi there.\end{code}
|
|
||||||
%
|
|
||||||
In theory, this would cause scsh to start up, set \ex{command-line-arguments}
|
|
||||||
to \ex{("Hi" "there.")}, load the source file \ex{ekko}, and exit.
|
|
||||||
|
|
||||||
However, the {\Unix} \ex{exec(2)} call will not handle multiple arguments
|
\subsubsection{VM options}
|
||||||
on the \ex{\#!} line, so this script won't work. We must instead invoke
|
|
||||||
the {\scm} vm with the single \cd{\\} argument, and put the rest of the
|
|
||||||
arguments on line two of the script. Here's the correct script:\footnote{
|
|
||||||
In fact, I'm playing fast and loose with the actual pathnames
|
|
||||||
used in this example: \ex{scshvm} is probably not going to be found in
|
|
||||||
\ex{/bin}. I've abbreviated things so the long argument lists will fit
|
|
||||||
into one line of text.
|
|
||||||
See the following sections for the full details.}
|
|
||||||
%
|
|
||||||
\begin{code}
|
|
||||||
#!/bin/scshvm \\
|
|
||||||
-o /bin/scshvm -i /lib/scsh.image -s
|
|
||||||
!#
|
|
||||||
(map (\l{arg} (display arg) (display " "))
|
|
||||||
command-line-arguments)
|
|
||||||
(newline)\end{code}
|
|
||||||
%
|
|
||||||
Now, the invocation starts as
|
|
||||||
\codex{ekko Hi there.}
|
|
||||||
and is expanded by exec(2) into
|
|
||||||
\begin{code}
|
|
||||||
/bin/scshvm \\ ekko Hi there.\end{code}
|
|
||||||
When scshvm starts up, it expands the ``\cd{\\}'' argument into the arguments
|
|
||||||
read from line two of \ex{ekko}, producing this argument list:
|
|
||||||
\begin{code}\cddollar
|
|
||||||
\underline{-o /bin/scshvm -i /lib/scsh.image -s ekko} Hi there.
|
|
||||||
$\uparrow$
|
|
||||||
{\rm{}Expanded from} \cd{\\} ekko\end{code}
|
|
||||||
%
|
|
||||||
With this argument list, processing proceeds as we intended.
|
|
||||||
|
|
||||||
\subsection{VM options}
|
|
||||||
The \ex{-o \var{object-file-name}} switch tells the vm where to find
|
The \ex{-o \var{object-file-name}} switch tells the vm where to find
|
||||||
relocation information for its foreign-function calls.
|
relocation information for its foreign-function calls.
|
||||||
Scsh will use a pre-compiled default if it is not specified.
|
Scsh will use a pre-compiled default if it is not specified.
|
||||||
Scsh must have this information to run,
|
Scsh \emph{must} have this information to run,
|
||||||
since scsh's syscall interfaces are done with foreign-function calls.
|
since scsh's syscall interfaces are done with foreign-function calls.
|
||||||
|
|
||||||
The \ex{-h} and \ex{-s} options tell the vm how much space to allocate
|
The \ex{-h} and \ex{-s} options tell the vm how much space to allocate
|
||||||
for the heap and stack.
|
for the heap and stack.
|
||||||
|
The heap size value is the total number of words allocated for the heap;
|
||||||
|
this space is then split into two semi-spaces for {\scm}'s stop-and-copy
|
||||||
|
collector.
|
||||||
|
|
||||||
\subsection{End options}
|
\subsubsection{End options}
|
||||||
End options terminate argument parsing.
|
End options terminate argument parsing.
|
||||||
The \ex{-i} switch is followed by the name of a heap image for the
|
The \ex{-i} switch is followed by the name of a heap image for the
|
||||||
vm to execute, and terminates vm argument parsing;
|
vm to execute.
|
||||||
following arguments are passed off to the heap image's top-level program.
|
The \var{image-file-name} string is also taken to be the name of the program
|
||||||
|
being executed by the VM; this name becomes the head of the argument
|
||||||
|
list passed to the heap image's top-level entry point.
|
||||||
|
The tail of the argument list is constructed from all following arguments.
|
||||||
|
|
||||||
The \ex{--} switch terminates argument parsing without giving
|
The \ex{--} switch terminates argument parsing without giving
|
||||||
a specific heap image; the vm will start up with using a default
|
a specific heap image; the vm will start up using a default
|
||||||
heap (whose location is compiled into the vm).
|
heap (whose location is compiled into the vm).
|
||||||
|
All the following arguments comprise the tail of the list passed off to
|
||||||
|
the heap image's top-level procedure.
|
||||||
|
|
||||||
Notice that you are not allowed to pass arguments to the heap image's
|
Notice that you are not allowed to pass arguments to the heap image's
|
||||||
top-level program (\eg, scsh) without delimiting them with \ex{-i}
|
top-level procedure (\eg, scsh) without delimiting them with \ex{-i}
|
||||||
or \ex{--} flags.
|
or \ex{--} flags.
|
||||||
|
|
||||||
\section{Scsh arguments}
|
\subsection{Inserting interpreter triggers into heap images}
|
||||||
\label{sec:scsh-args}
|
{\scm}'s heap image format allows for an informational header:
|
||||||
|
when the vm loads in a heap image, it ignores all data occurring before
|
||||||
|
the first control-L character (\textsc{Ascii} 12).
|
||||||
|
This means that you can insert a ``\ex{\#!}'' trigger line into a
|
||||||
|
heap image, making it a form of executable ``shell script.''
|
||||||
|
Since the vm requires multiple arguments to be given on the command
|
||||||
|
line, you must use the meta-switch.
|
||||||
|
Here's an example heap-image header:
|
||||||
|
\begin{code}
|
||||||
|
#!/usr/local/lib/scsh/scshvm \\
|
||||||
|
-o /usr/local/lib/scsh/scshvm -i
|
||||||
|
{\ldots} \textnormal{\emph{Your heap image goes here}} \ldots\end{code}
|
||||||
|
|
||||||
Scsh's top-level argument parser takes arguments in a simple
|
\subsection{Inserting a double-level trigger into Scheme programs}
|
||||||
format:
|
If you're a nerd, you may enjoy doing a double-level machine shift
|
||||||
\codex{scsh [\var{end-option} \vari{arg}1 {\ldots} \vari{arg}n]}
|
in the trigger line of your Scheme programs with the following magic:
|
||||||
where
|
\begin{code}\small
|
||||||
\begin{inset}
|
#!/usr/local/lib/scsh/scshvm \\
|
||||||
\begin{tabular}{ll}
|
-o /usr/local/lib/scsh/scshvm -i /usr/local/lib/scsh/scsh.image -s
|
||||||
\var{end-option:} & \ex{-s} \var{script} \\
|
!#
|
||||||
& \ex{--}
|
{\ldots} \textnormal{\emph{Your Scheme program goes here}} \ldots\end{code}
|
||||||
\end{tabular}
|
|
||||||
\end{inset}
|
|
||||||
The \ex{-s} argument causes scsh to load a script file and exit.
|
|
||||||
It also terminates argument parsing; following arguments are passed
|
|
||||||
to the scsh program as the value of \ex{command-line-arguments}.
|
|
||||||
|
|
||||||
If the \ex{-s} argument is not given, scsh runs in interactive mode,
|
\section{Compiling scsh programs}
|
||||||
with a standard {\scm} prompt-read-eval-print loop.
|
Scsh allows you to create a heap image with your own top-level procedure.
|
||||||
|
|
||||||
The \ex{--} switch terminates argument parsing without specifying a
|
|
||||||
script to load; it allows the user to pass arguments to an interactive scsh.
|
|
||||||
|
|
||||||
Shell scripts can be written and invoked with a \ex{\#!} initial line.
|
|
||||||
Scsh defines the sequence \ex{\#!} to be a read-macro similar
|
|
||||||
to the comment character \ex{;}.
|
|
||||||
The read-macro causes scsh to skip characters until it reads a newline,
|
|
||||||
\ex{!}, \ex{\#}, newline sequence.
|
|
||||||
So an initial \ex{\#!} line is ignored by scsh.
|
|
||||||
|
|
||||||
% Since there is no standalone scsh binary, scsh scripts must do a double
|
|
||||||
% level-shift, invoking the vm on the scsh heap image on the scsh script.
|
|
||||||
% The appropriate magic top three lines are:
|
|
||||||
% \begin{code}
|
|
||||||
% #!/usr/local/bin/scshvm \\
|
|
||||||
% -o /usr/local/bin/scshvm -i /usr/local/lib/scsh/scsh.image -s
|
|
||||||
% !#
|
|
||||||
% {\ldots} \textnormal{\emph{Your Scheme code goes here}} \ldots\end{code}
|
|
||||||
|
|
||||||
\section{Compiling shell scripts}
|
|
||||||
The {\Scheme} implementation of scsh allows you to create a heap image
|
|
||||||
with your own top-level procedure.
|
|
||||||
Adding the pair of lines
|
Adding the pair of lines
|
||||||
\begin{code}
|
\begin{code}
|
||||||
#!/usr/local/bin/scshvm \\\\
|
#!/usr/local/lib/scsh/scshvm \\
|
||||||
-o /usr/local/bin/scshvm -i
|
-o /usr/local/lib/scsh/scshvm -i\end{code}
|
||||||
\end{code}
|
|
||||||
to the top of the heap image will turn it into an executable {\Unix} file.
|
to the top of the heap image will turn it into an executable {\Unix} file.
|
||||||
|
|
||||||
|
You can create heap images with the following two procedures.
|
||||||
|
|
||||||
\defun{dump-scsh-program}{main fname}{\undefined}
|
\defun{dump-scsh-program}{main fname}{\undefined}
|
||||||
\begin{desc}
|
\begin{desc}
|
||||||
This procedure writes out a scsh heap image. When the
|
This procedure writes out a scsh heap image. When the
|
||||||
heap image is executed by the {\Scheme} vm, it will call
|
heap image is executed by the {\scm} vm, it will call
|
||||||
the \var{main} procedure on no arguments and then exit.
|
the \var{main} procedure, passing it the vm's argument list.
|
||||||
The {\Scheme} vm will parse command-line arguments as
|
When \ex{main} returns an integer value $i$, the vm exits with
|
||||||
described in section~\ref{sec:vm-args}, and bind remaining
|
exit status $i$.
|
||||||
arguments to the \ex{command-line-arguments} variable before
|
The {\Scheme} vm will parse command-line switches as
|
||||||
calling \ex{main}. Further argument parsing (as described for
|
described in section~\ref{sec:vm-args}; remaining arguments
|
||||||
scsh in section~\ref{sec:scsh-args} is not performed.
|
form the tail of the command-line list that is passed to \ex{main}.
|
||||||
|
(The head of the list is the name of the program being executed
|
||||||
|
by the vm.)
|
||||||
|
Further argument parsing
|
||||||
|
(as described for scsh in section~\ref{sec:scsh-switches})
|
||||||
|
is not performed.
|
||||||
|
|
||||||
The heap image created by \ex{dump-scsh-program} has unused
|
The heap image created by \ex{dump-scsh-program} has unused
|
||||||
code and data pruned out, so small programs compile to much smaller
|
code and data pruned out, so small programs compile to much smaller
|
||||||
heap images.
|
heap images.
|
||||||
\end{desc}
|
\end{desc}
|
||||||
|
|
||||||
|
\defun{dump-scsh}{fname}{\undefined}
|
||||||
|
\begin{desc}
|
||||||
|
This procedure writes out a heap image with the standard
|
||||||
|
scsh top-level.
|
||||||
|
When the image is resumed by the vm, it will parse and
|
||||||
|
execute scsh command-line switches as described in section
|
||||||
|
\ref{sec:scsh-switches}.
|
||||||
|
|
||||||
|
You can use this procedure to write out custom scsh heap images
|
||||||
|
that have specific packages preloaded and start up in specific
|
||||||
|
packages.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
Unfortunately, {\scm} does not support separate compilation of
|
||||||
|
Scheme files or Scheme modules.
|
||||||
|
The only way to compile is to load source and then dump out a
|
||||||
|
heap image.
|
||||||
|
One occasionally hears rumours that this is being addressed
|
||||||
|
by the {\scm} development team.
|
||||||
|
|
||||||
|
\section{Statically linking heap images}
|
||||||
|
Brian Carlstrom has written code to process {\scm} heap images
|
||||||
|
into \ex{.o} files that can be linked with a virtual machine
|
||||||
|
binary to produce a standalone machine-code executable.
|
||||||
|
|
||||||
|
The source code comes with the current distribution, but it has not been
|
||||||
|
integrated into the system or documented in time for this
|
||||||
|
release.
|
||||||
|
|
||||||
|
%Either he integrates it into the system and documents it for release
|
||||||
|
%0.4, or his body will soon be occupying a shallow grave behind Tech Square.
|
||||||
|
|
||||||
|
|
||||||
\section{Standard file locations}
|
\section{Standard file locations}
|
||||||
Because the scshvm binary is intended to be used for writing shell
|
Because the scshvm binary is intended to be used for writing shell
|
||||||
scripts, it is important that the binary be installed in a standard
|
scripts, it is important that the binary be installed in a standard
|
||||||
|
|
@ -219,6 +765,7 @@ with a symbolic link to it from
|
||||||
The {\scm} image format allows heap images to have \ex{\#!} triggers,
|
The {\scm} image format allows heap images to have \ex{\#!} triggers,
|
||||||
so \ex{scsh.image} should have a \ex{\#!} trigger of the following form:
|
so \ex{scsh.image} should have a \ex{\#!} trigger of the following form:
|
||||||
\begin{code}
|
\begin{code}
|
||||||
#!/usr/local/bin/scshvm \\
|
#!/usr/local/lib/scsh/scshvm \\
|
||||||
-o /usr/local/bin/scshvm -i
|
-o /usr/local/lib/scsh/scshvm -i
|
||||||
{\ldots} \textnormal{\emph{heap image goes here}} \ldots\end{code}
|
{\ldots} \textnormal{\emph{heap image goes here}} \ldots\end{code}
|
||||||
|
|
||||||
|
|
|
||||||
|
|
@ -1,11 +1,12 @@
|
||||||
|
% -*- latex -*-
|
||||||
\chapter{Strings and characters}
|
\chapter{Strings and characters}
|
||||||
|
|
||||||
Scsh provides a set of procedures for processing strings and characters.
|
Scsh provides a set of procedures for processing strings and characters.
|
||||||
The procedures provided match regular expressions, search strings,
|
The procedures provided match regular expressions, search strings,
|
||||||
parse file-names, and manipulate sets of characters.
|
parse file-names, and manipulate sets of characters.
|
||||||
|
|
||||||
Also see chapter \ref{chapt:fr-awk} on record I/O, field parsing,
|
Also see chapters \ref{chapt:rdelim} and \ref{chapt:fr-awk}
|
||||||
and the awk loop.
|
on record I/O, field parsing, and the awk loop.
|
||||||
The procedures documented there allow you to read character-delimited
|
The procedures documented there allow you to read character-delimited
|
||||||
records from ports, use regular expressions to split the records into fields
|
records from ports, use regular expressions to split the records into fields
|
||||||
(for example, splitting a string at every occurrence of colon or white-space),
|
(for example, splitting a string at every occurrence of colon or white-space),
|
||||||
|
|
@ -35,7 +36,7 @@ The code uses Henry Spencer's regular expression package.
|
||||||
\end{defundesc}
|
\end{defundesc}
|
||||||
|
|
||||||
\begin{defundesc} {match:start} {match [match-number]} \fixnum
|
\begin{defundesc} {match:start} {match [match-number]} \fixnum
|
||||||
Returns the start position of the match denoted by \var{match-number}
|
Returns the start position of the match denoted by \var{match-number}.
|
||||||
The whole regexp is 0. Each further number represents positions
|
The whole regexp is 0. Each further number represents positions
|
||||||
enclosed by \ex{(\ldots)} sections. \var{Match-number} defaults to 0.
|
enclosed by \ex{(\ldots)} sections. \var{Match-number} defaults to 0.
|
||||||
\end{defundesc}
|
\end{defundesc}
|
||||||
|
|
@ -50,10 +51,9 @@ The code uses Henry Spencer's regular expression package.
|
||||||
\var{Match-number} defaults to 0 (the whole match).
|
\var{Match-number} defaults to 0 (the whole match).
|
||||||
\end{defundesc}
|
\end{defundesc}
|
||||||
|
|
||||||
\remark{
|
\oops{Scsh regex matching doesn't currently flag un-matched subexpressions
|
||||||
What do these guys do when there is no match corresponding to
|
in the \ex{match:begin}, \ex{match:end}, and \ex{match:substring} functions.
|
||||||
\var{match-number}?
|
This needs to be fixed.}
|
||||||
Return {\sharpf} or signal error? {\sharpf} probably best.}
|
|
||||||
|
|
||||||
Regular expression matching compiles patterns into special data
|
Regular expression matching compiles patterns into special data
|
||||||
structures which can be efficiently used to match against strings.
|
structures which can be efficiently used to match against strings.
|
||||||
|
|
@ -95,13 +95,9 @@ In other words, it quotes the regular expression, prepending backslashes
|
||||||
to all the special regexp characters in \var{str}.
|
to all the special regexp characters in \var{str}.
|
||||||
\begin{code}
|
\begin{code}
|
||||||
(regexp-quote "*Hello* world.")
|
(regexp-quote "*Hello* world.")
|
||||||
{\evalto}"\\*Hello\\* world\\."\end{code}
|
{\evalto}"\\\\*Hello\\\\* world\\\\."\end{code}
|
||||||
\end{desc}
|
\end{desc}
|
||||||
|
|
||||||
\oops{Scsh regex matching doesn't currently flag un-matched subexpressions
|
|
||||||
in the \ex{match:begin}, \ex{match:end}, and \ex{match:substring} functions.
|
|
||||||
This needs to be fixed.}
|
|
||||||
|
|
||||||
\subsection{Other string manipulation facilities}
|
\subsection{Other string manipulation facilities}
|
||||||
|
|
||||||
\defun {index} {string char [start]} {{\fixnum} or false}
|
\defun {index} {string char [start]} {{\fixnum} or false}
|
||||||
|
|
@ -191,8 +187,8 @@ slashes to a single slash.
|
||||||
|
|
||||||
A file-name in \emph{directory form} is either a file-name terminated by
|
A file-name in \emph{directory form} is either a file-name terminated by
|
||||||
a slash, \eg, ``\ex{/src/des/}'', or the empty string, ``''.
|
a slash, \eg, ``\ex{/src/des/}'', or the empty string, ``''.
|
||||||
The empty string corresponds to the current working directory, who's
|
The empty string corresponds to the current working directory,
|
||||||
file-name is dot (``\ex{.}'').
|
whose file-name is dot (``\ex{.}'').
|
||||||
Working backwards from the append-a-slash rule,
|
Working backwards from the append-a-slash rule,
|
||||||
we extend the syntax of {\Posix} file-names to define the empty string
|
we extend the syntax of {\Posix} file-names to define the empty string
|
||||||
to be a file-name form of the root directory ``\ex{/}''.
|
to be a file-name form of the root directory ``\ex{/}''.
|
||||||
|
|
@ -223,6 +219,27 @@ interpreted in file-name form, \ie, as root.
|
||||||
|
|
||||||
\subsubsection{Procedures}
|
\subsubsection{Procedures}
|
||||||
|
|
||||||
|
\defun {file-name-directory?} {fname} \boolean
|
||||||
|
\defunx {file-name-non-directory?} {fname} \boolean
|
||||||
|
\begin{desc}
|
||||||
|
These predicates return true if the string is in directory form, or
|
||||||
|
file-name form (see the above discussion of these two forms).
|
||||||
|
Note that they both return true on the ambiguous case of empty string,
|
||||||
|
which is both a directory (current working directory), and a file name
|
||||||
|
(the file-system root).
|
||||||
|
\begin{center}
|
||||||
|
\begin{tabular}{lll}
|
||||||
|
File name & \ex{\ldots-directory?} & \ex{\ldots-non-directory?} \\
|
||||||
|
\hline
|
||||||
|
\ex{"src/des"} & \ex{\sharpf} & \ex{\sharpt} \\
|
||||||
|
\ex{"src/des/"} & \ex{\sharpt} & \ex{\sharpf} \\
|
||||||
|
\ex{"/"} & \ex{\sharpt} & \ex{\sharpf} \\
|
||||||
|
\ex{"."} & \ex{\sharpf} & \ex{\sharpt} \\
|
||||||
|
\ex{""} & \ex{\sharpt} & \ex{\sharpt}
|
||||||
|
\end{tabular}
|
||||||
|
\end{center}
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
\begin{defundesc} {file-name-as-directory} {fname} \str
|
\begin{defundesc} {file-name-as-directory} {fname} \str
|
||||||
Convert a file-name to directory form.
|
Convert a file-name to directory form.
|
||||||
Basically, add a trailing slash if needed:
|
Basically, add a trailing slash if needed:
|
||||||
|
|
@ -465,14 +482,14 @@ is also frequently useful for expanding file-names.
|
||||||
\label{sec:char-sets}
|
\label{sec:char-sets}
|
||||||
|
|
||||||
Scsh provides a \ex{char-set} type for expressing sets of characters.
|
Scsh provides a \ex{char-set} type for expressing sets of characters.
|
||||||
These sets are used by some of the delimited input procedures
|
These sets are used by some of the delimited-input procedures
|
||||||
(section~\ref{sec:field-reader}).
|
(section~\ref{sec:field-reader}).
|
||||||
The character set package that scsh uses was taken from Project Mac's
|
The character set package that scsh uses was taken from Project Mac's
|
||||||
MIT Scheme.
|
MIT Scheme.
|
||||||
|
|
||||||
\defun{char-set?}{x}\boolean
|
\defun{char-set?}{x}\boolean
|
||||||
\begin{desc}
|
\begin{desc}
|
||||||
Returns true if the object \ex{x} is a character set.
|
Returns true if the object \var{x} is a character set.
|
||||||
\end{desc}
|
\end{desc}
|
||||||
|
|
||||||
\subsection{Creating character sets}
|
\subsection{Creating character sets}
|
||||||
|
|
@ -501,7 +518,7 @@ Returns a character set containing every character \var{c} such that
|
||||||
\defun{ascii-range->char-set}{lower upper}{char-set}
|
\defun{ascii-range->char-set}{lower upper}{char-set}
|
||||||
\begin{desc}
|
\begin{desc}
|
||||||
Returns a character set containing every character whose {\Ascii}
|
Returns a character set containing every character whose {\Ascii}
|
||||||
code lies in the range $[\var{lower},\var{upper}]$ inclusive.
|
code lies in the half-open range $[\var{lower},\var{upper})$.
|
||||||
\end{desc}
|
\end{desc}
|
||||||
|
|
||||||
\subsection{Querying character sets}
|
\subsection{Querying character sets}
|
||||||
|
|
@ -510,9 +527,19 @@ code lies in the range $[\var{lower},\var{upper}]$ inclusive.
|
||||||
This procedure returns a list of the members of \var{char-set}.
|
This procedure returns a list of the members of \var{char-set}.
|
||||||
\end{desc}
|
\end{desc}
|
||||||
|
|
||||||
\defunx{char-set-member?}{char char-set}\boolean
|
\defunx{char-set-contains?}{char-set char}\boolean
|
||||||
\begin{desc}
|
\begin{desc}
|
||||||
This procedure tests \var{char} for membership in set \var{char-set}.
|
This procedure tests \var{char} for membership in set \var{char-set}.
|
||||||
|
\remark{Previous releases of scsh called this procedure \ex{char-set-member?},
|
||||||
|
reversing the order of the arguments.
|
||||||
|
This made sense, but was unfortunately the reverse order in which the
|
||||||
|
arguments appear in MIT Scheme.
|
||||||
|
A reasonable argument order was not backwards-compatible with MIT Scheme;
|
||||||
|
on the other hand, the MIT Scheme argument order was counter-intuitive
|
||||||
|
and at odds with common mathematical notation and the \ex{member} family
|
||||||
|
of R4RS procedures.
|
||||||
|
|
||||||
|
We sought to escape the dilemma by shifting to a new name.}
|
||||||
\end{desc}
|
\end{desc}
|
||||||
|
|
||||||
\subsection{Character set algebra}
|
\subsection{Character set algebra}
|
||||||
|
|
|
||||||
File diff suppressed because it is too large
Load Diff
|
|
@ -0,0 +1,17 @@
|
||||||
|
%&latex -*- latex -*-
|
||||||
|
|
||||||
|
\documentclass[twoside]{report}
|
||||||
|
\usepackage{code,boxedminipage,draftfooters,palatino,ct,makeidx,
|
||||||
|
headings,mantitle,array,matter,mysize10}
|
||||||
|
|
||||||
|
\parskip = 3pt plus 3pt
|
||||||
|
\sloppy
|
||||||
|
|
||||||
|
\input{decls}
|
||||||
|
%%% End preamble
|
||||||
|
|
||||||
|
\begin{document}
|
||||||
|
|
||||||
|
\include{args}
|
||||||
|
|
||||||
|
\end{document}
|
||||||
|
|
@ -1,14 +1,31 @@
|
||||||
%&latex -*- latex -*-
|
>%&latex -*- latex -*-
|
||||||
|
|
||||||
\chapter{Todo}
|
\chapter{Todo}
|
||||||
{\parindent 0pt
|
{\parindent 0pt
|
||||||
|
|
||||||
The {\LaTeX} hackery needs yet another serious pass. Most importantly,
|
We'd love to have have people implement these subsystems and
|
||||||
|
fold them into the scsh release:
|
||||||
|
\begin{itemize}
|
||||||
|
\item More network protocols. Telnet and ftp would be the most important.
|
||||||
|
\item An ILU interface.
|
||||||
|
\item An RPC system, with ``tail-recursion.''
|
||||||
|
\item Interfaces to relational db's. This would be quite useful for
|
||||||
|
Web servers.
|
||||||
|
\end{itemize}
|
||||||
|
|
||||||
|
Manual hacking:
|
||||||
|
\begin{itemize}
|
||||||
|
\item The {\LaTeX} hackery needs yet another serious pass. Most importantly,
|
||||||
long procedure ``declarations'' need to be broken across two lines.
|
long procedure ``declarations'' need to be broken across two lines.
|
||||||
|
|
||||||
Fix up 0-or-more and 1-or-more parameter typesetting, with subscripts.
|
\item Fix up 0-or-more and 1-or-more parameter typesetting, with subscripts.
|
||||||
|
|
||||||
Parameter subscripts need to be made real subscripts.
|
\item Parameter subscripts need to be made real subscripts.
|
||||||
|
|
||||||
|
\item Soup up the markup processor, and redo manual in markup. Generate
|
||||||
|
LaTeX, HTML, and info versions. Alternatively, persuade some kind
|
||||||
|
soul to hand-port manual to HTML or info.
|
||||||
|
\end{itemize}
|
||||||
|
|
||||||
Job control, after \ex{jcontrol.scm}
|
Job control, after \ex{jcontrol.scm}
|
||||||
|
|
||||||
|
|
@ -21,11 +38,7 @@ Interrupt system.
|
||||||
Make it all coexist with S48 threads as well as can be done for Unix.
|
Make it all coexist with S48 threads as well as can be done for Unix.
|
||||||
The DEC SRC tech report gives a good discussion of the issues.
|
The DEC SRC tech report gives a good discussion of the issues.
|
||||||
|
|
||||||
Support for file locking: \ex{(lock-file fd op)}, \ex{with-file-locked}, \ldots
|
Testing broken symlinks---new value for \var{chase?} flag?
|
||||||
|
|
||||||
Testing broken symlinks -- new value for \var{chase?} flag?
|
|
||||||
|
|
||||||
Interactive flag machinery
|
|
||||||
|
|
||||||
Rename and release \ex{ensure-file-name-is-\{non,\}directory}.
|
Rename and release \ex{ensure-file-name-is-\{non,\}directory}.
|
||||||
|
|
||||||
|
|
@ -35,18 +48,7 @@ Other things should be available: hash tables, sort, list utils, pattern
|
||||||
matchers. But things start to overload. The module system is the appropriate
|
matchers. But things start to overload. The module system is the appropriate
|
||||||
way to use these.
|
way to use these.
|
||||||
|
|
||||||
Support for writing scripts that use the module language.
|
|
||||||
|
|
||||||
Need calls to control port i/o buffering.
|
|
||||||
|
|
||||||
Need to do file-control (\ie, \ex{fcntl()}).
|
Need to do file-control (\ie, \ex{fcntl()}).
|
||||||
\ex{fcntl} is ugly.
|
\ex{fcntl} is ugly.
|
||||||
Better to have a procedure for each different operation.
|
Better to have a procedure for each different operation.
|
||||||
|
|
||||||
Tty stuff and control tty.
|
|
||||||
|
|
||||||
More documentation for the \ex{wait()} machinery.
|
|
||||||
|
|
||||||
We need a general time/date parser, that can convert strings like
|
|
||||||
``Thursday after Christmas'' into date records.
|
|
||||||
}
|
}
|
||||||
|
|
|
||||||
|
|
@ -0,0 +1,707 @@
|
||||||
|
%&latex -*- latex -*-
|
||||||
|
% Fix OXTABS footnote bug
|
||||||
|
% Figures should be dumped out earlier? Pack two to a page?
|
||||||
|
|
||||||
|
\section{Terminal device control}
|
||||||
|
\label{sect:tty}
|
||||||
|
|
||||||
|
\newcommand{\fr}[1]{\makebox[0pt][r]{#1}}
|
||||||
|
|
||||||
|
% \ex{#1} and also generates an index entry.
|
||||||
|
\newcommand{\exi}[1]{\index{#1@\texttt{#1}}\ex{#1}}
|
||||||
|
\newcommand{\indextt}[1]{\index{#1@\texttt{#1}}}
|
||||||
|
|
||||||
|
Scsh provides a complete set of routines for manipulating terminal
|
||||||
|
devices---putting them in ``raw'' mode, changing and querying their
|
||||||
|
special characters, modifying their i/o speeds, and so forth.
|
||||||
|
The scsh interface is designed both for generality and portability
|
||||||
|
across different Unix platforms, so you don't have to rewrite your
|
||||||
|
program each time you move to a new system.
|
||||||
|
We've also made an effort to use reasonable, Scheme-like names for
|
||||||
|
the multitudinous named constants involved, so when you are reading
|
||||||
|
code, you'll have less likelihood of getting lost in a bewildering
|
||||||
|
maze of obfuscatory constants named \ex{ICRNL}, \ex{INPCK}, \ex{IUCLC},
|
||||||
|
and \ex{ONOCR}.
|
||||||
|
|
||||||
|
This section can only lay out the basic functionality of the terminal
|
||||||
|
device interface.
|
||||||
|
For further details, see the termios(3) man page on your system,
|
||||||
|
or consult one of the standard {\Unix} texts.
|
||||||
|
|
||||||
|
\subsection{Portability across OS variants}
|
||||||
|
Terminal-control software is inescapably complex, ugly, and low-level.
|
||||||
|
Unix variants each provide their own way of controlling terminal
|
||||||
|
devices, making it difficult to provide interfaces that are
|
||||||
|
portable across different Unix systems.
|
||||||
|
Scsh's terminal support is based primarily upon the {\Posix} termios
|
||||||
|
interface.
|
||||||
|
Programs that can be written using only the {\Posix} interface are likely
|
||||||
|
to be widely portable.
|
||||||
|
|
||||||
|
The bulk of the documentation that follows consists of several pages worth
|
||||||
|
of tables defining different named constants that enable and disable different
|
||||||
|
features of the terminal driver.
|
||||||
|
Some of these flags are {\Posix}; others are taken from the two common
|
||||||
|
branches of Unix development, SVR4 and 4.3+ Berkeley.
|
||||||
|
Scsh guarantees that the non-{\Posix} constants will be bound identifiers.
|
||||||
|
\begin{itemize}
|
||||||
|
\item If your OS supports a particular non-{\Posix} flag,
|
||||||
|
its named constant will be bound to the flag's value.
|
||||||
|
\item If your OS doesn't support the flag, its named constant
|
||||||
|
will be present, but bound to \sharpf.
|
||||||
|
\end{itemize}
|
||||||
|
This means that if you want to use SVR4 or Berkeley features in a program,
|
||||||
|
your program can portably test the values of the flags before using
|
||||||
|
them---the flags can reliably be referenced without producing OS-dependent
|
||||||
|
``unbound variable'' errors.
|
||||||
|
|
||||||
|
Finally, note that although {\Posix}, SVR4, and Berkeley cover the lion's
|
||||||
|
share of the terminal-driver functionality,
|
||||||
|
each operating system inevitably has non-standard extensions.
|
||||||
|
While a particular scsh implementation may provide these extensions,
|
||||||
|
they are not portable, and so are not documented here.
|
||||||
|
|
||||||
|
\subsection{The tty-info record type}
|
||||||
|
|
||||||
|
The primary data-structure that describes a terminal's mode is
|
||||||
|
a \ex{tty-info} record, defined as follows:
|
||||||
|
\index{tty-info record type}
|
||||||
|
\indextt{tty-info:control-chars}
|
||||||
|
\indextt{tty-info:input-flags}
|
||||||
|
\indextt{tty-info:output-flags}
|
||||||
|
\indextt{tty-info:control-flags}
|
||||||
|
\indextt{tty-info:local-flags}
|
||||||
|
\indextt{tty-info:input-speed}
|
||||||
|
\indextt{tty-info:output-speed}
|
||||||
|
\indextt{tty-info:min}
|
||||||
|
\indextt{tty-info:time}
|
||||||
|
\indextt{tty-info?}
|
||||||
|
\begin{code}
|
||||||
|
(define-record tty-info
|
||||||
|
control-chars ; String: Magic input chars
|
||||||
|
input-flags ; Int: Input processing
|
||||||
|
output-flags ; Int: Output processing
|
||||||
|
control-flags ; Int: Serial-line control
|
||||||
|
local-flags ; Int: Line-editting UI
|
||||||
|
input-speed ; Int: Code for input speed
|
||||||
|
output-speed ; Int: Code for output speed
|
||||||
|
min ; Int: Raw-mode input policy
|
||||||
|
time) ; Int: Raw-mode input policy\end{code}
|
||||||
|
|
||||||
|
\subsubsection{The control-characters string}
|
||||||
|
The \ex{control-chars} field is a character string;
|
||||||
|
its characters may be indexed by integer values taken from
|
||||||
|
table~\ref{table:ttychars}.
|
||||||
|
|
||||||
|
As discussed above,
|
||||||
|
only the {\Posix} entries in table~\ref{table:ttychars} are guaranteed
|
||||||
|
to be legal, integer indices.
|
||||||
|
A program can reliably test the OS to see if the non-{\Posix}
|
||||||
|
characters are supported by checking the index constants.
|
||||||
|
If the control-character function is supported by the terminal driver,
|
||||||
|
then the corresponding index will be bound to an integer;
|
||||||
|
if it is not supported, the index will be bound to \sharpf.
|
||||||
|
|
||||||
|
To disable a given control-character function, set its corresponding
|
||||||
|
entry in the \ex{tty-info:control-chars} string to the
|
||||||
|
special character \exi{disable-tty-char}
|
||||||
|
(and then use the \ex{(set-tty-info \var{fd/port} \var{info})} procedure
|
||||||
|
to update the terminal's state).
|
||||||
|
|
||||||
|
\subsubsection{The flag fields}
|
||||||
|
The \ex{tty-info} record's \ex{input-flags}, \ex{output-flags},
|
||||||
|
\ex{control-flags}, and \ex{local-flags} fields are all bit sets
|
||||||
|
represented as two's-complement integers.
|
||||||
|
Their values are composed by or'ing together values taken from
|
||||||
|
the named constants listed in tables~\ref{table:ttyin}
|
||||||
|
through \ref{table:ttylocal}.
|
||||||
|
|
||||||
|
As discussed above,
|
||||||
|
only the {\Posix} entries listed in these tables are guaranteed
|
||||||
|
to be legal, integer flag values.
|
||||||
|
A program can reliably test the OS to see if the non-{\Posix}
|
||||||
|
flags are supported by checking the named constants.
|
||||||
|
If the feature is supported by the terminal driver,
|
||||||
|
then the corresponding flag will be bound to an integer;
|
||||||
|
if it is not supported, the flag will be bound to \sharpf.
|
||||||
|
|
||||||
|
%%%%% I managed to squeeze this into the DEFINE-RECORD's comments.
|
||||||
|
% Here is a small table classifying the four flag fields by
|
||||||
|
% the kind of features they determine:
|
||||||
|
% \begin{center}
|
||||||
|
% \begin{tabular}{|ll|}\hline
|
||||||
|
% Field & Affects \\ \hline \hline
|
||||||
|
% \ex{input-flags} & Processing of input chars \\
|
||||||
|
% \ex{output-flags} & Processing of output chars \\
|
||||||
|
% \ex{control-flags} & Controlling of terminal's serial line \\
|
||||||
|
% \ex{local-flags} & Details of the line-editting user interface \\
|
||||||
|
% \hline
|
||||||
|
% \end{tabular}
|
||||||
|
% \end{center}
|
||||||
|
|
||||||
|
%%%
|
||||||
|
%%% The figures used to go here.
|
||||||
|
%%%
|
||||||
|
|
||||||
|
\subsubsection{The speed fields}
|
||||||
|
The \ex{input-speed} and \ex{output-speed} fields determine the
|
||||||
|
I/O rate of the terminal's line.
|
||||||
|
The value of these fields is an integer giving the speed
|
||||||
|
in bits-per-second.
|
||||||
|
The following speeds are supported by {\Posix}:
|
||||||
|
\begin{center}
|
||||||
|
\begin{tabular}{rrrr}
|
||||||
|
0 & 134 & 600 & 4800 \\
|
||||||
|
50 & 150 & 1200 & 9600 \\
|
||||||
|
75 & 200 & 1800 & 19200 \\
|
||||||
|
110 & 300 & 2400 & 38400 \\
|
||||||
|
\end{tabular}
|
||||||
|
\end{center}
|
||||||
|
Your OS may accept others; it may also allow the special symbols
|
||||||
|
\ex{'exta} and \ex{'extb}.
|
||||||
|
|
||||||
|
\subsubsection{The min and time fields}
|
||||||
|
The integer \ex{min} and \ex{time} fields determine input blocking
|
||||||
|
behaviour during non-canonical (raw) input; otherwise, they are ignored.
|
||||||
|
See the termios(3) man page for further details.
|
||||||
|
|
||||||
|
Be warned that {\Posix} allows the base system call's representation
|
||||||
|
of the \ex{tty-info} record to share storage for the \ex{min} field
|
||||||
|
and the \ex{ttychar/eof} element of the control-characters string,
|
||||||
|
and for the \ex{time} field and the \ex{ttychar/eol} element
|
||||||
|
of the control-characters string.
|
||||||
|
Many implementations in fact do this.
|
||||||
|
|
||||||
|
To stay out of trouble, set the \ex{min} and \ex{time} fields only
|
||||||
|
if you are putting the terminal into raw mode;
|
||||||
|
set the eof and eol control-characters only if you are putting
|
||||||
|
the terminal into canonical mode.
|
||||||
|
It's ugly, but it's {\Unix}.
|
||||||
|
|
||||||
|
\subsection{Using tty-info records}
|
||||||
|
|
||||||
|
\defun{make-tty-info}{if of cf lf ispeed ospeed min time}
|
||||||
|
{tty-info-record}
|
||||||
|
\defunx{copy-tty-info}{tty-info-record}{tty-info-record}
|
||||||
|
\begin{desc}
|
||||||
|
These procedures make it possible to create new \ex{tty-info} records.
|
||||||
|
The typical method for creating a new record is to copy one retrieved
|
||||||
|
by a call to the \ex{tty-info} procedure, then modify the copy as desired.
|
||||||
|
Note that the \ex{make-tty-info} procedure does not take a parameter
|
||||||
|
to define the new record's control characters.\footnote{
|
||||||
|
Why? Because the length of the string varies from Unix to Unix.
|
||||||
|
For example, the word-erase control character (typically control-w)
|
||||||
|
is provided by most Unixes, but not part of the {\Posix} spec.}
|
||||||
|
Instead, it simply returns a \ex{tty-info} record whose control-character
|
||||||
|
string has all elements initialised to {\Ascii} nul.
|
||||||
|
You may then install the special characters by assigning to the string.
|
||||||
|
Similarly, the control-character string in the record produced by
|
||||||
|
\ex{copy-tty-info} does not share structure with the string in the record
|
||||||
|
being copied, so you may mutate it freely.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
|
||||||
|
\defun{tty-info}{fd/port}{tty-info-record}
|
||||||
|
\begin{desc}
|
||||||
|
The \var{fd/port} parameter is an integer file descriptor or Scheme I/O port
|
||||||
|
opened on a terminal device.
|
||||||
|
This procedure returns a \ex{tty-info} record describing the terminal's
|
||||||
|
current mode.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
\defun {set-tty-info/now} {fd/port info}{no-value}
|
||||||
|
\defunx{set-tty-info/drain}{fd/port info}{no-value}
|
||||||
|
\defunx{set-tty-info/flush}{fd/port info}{no-value}
|
||||||
|
\begin{desc}
|
||||||
|
The \var{fd/port} parameter is an integer file descriptor or Scheme I/O port
|
||||||
|
opened on a terminal device.
|
||||||
|
The procedure chosen determines when and how the terminal's mode is altered:
|
||||||
|
\begin{center}
|
||||||
|
\begin{tabular}{|ll|} \hline
|
||||||
|
Procedure & Meaning \\ \hline \hline
|
||||||
|
\ex{set-tty-info/now} & Make change immediately. \\
|
||||||
|
\ex{set-tty-info/drain} & Drain output, then change. \\
|
||||||
|
\ex{set-tty-info/flush} & Drain output, flush input, then change. \\ \hline
|
||||||
|
\end{tabular}
|
||||||
|
\end{center}
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
\subsection{Other terminal-device procedures}
|
||||||
|
\defun{send-tty-break}{fd/port [duration]}{no-value}
|
||||||
|
\begin{desc}
|
||||||
|
Send a break signal on the terminal associated with file descriptor
|
||||||
|
or Scheme I/O port \var{fd/port}.
|
||||||
|
A break signal is a sequence of continuous zeros on the terminal's transmission
|
||||||
|
line.
|
||||||
|
|
||||||
|
The \var{duration} argument determines the length of the break signal.
|
||||||
|
A zero value (the default) causes a break of between
|
||||||
|
0.25 and 0.5 seconds to be sent;
|
||||||
|
other values determine a period in a manner that will depend upon local
|
||||||
|
community standards.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
\defun{drain-tty}{fd/port}{no-value}
|
||||||
|
\begin{desc}
|
||||||
|
This procedure waits until all the output written to the
|
||||||
|
terminal device has been transmitted to the device.
|
||||||
|
If \var{fd/port} is an output port with buffered I/O
|
||||||
|
enabled, then the port's buffered characters are flushed before
|
||||||
|
waiting for the device to drain.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
\defun {flush-tty/input} {fd/port}{no-value}
|
||||||
|
\defunx{flush-tty/output}{fd/port}{no-value}
|
||||||
|
\defunx{flush-tty/both} {fd/port}{no-value}
|
||||||
|
\begin{desc}
|
||||||
|
These procedures discard the unread input chars or unwritten
|
||||||
|
output chars in the tty's kernel buffers.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
\defun {start-tty-output}{fd/port} {no-value}
|
||||||
|
\defunx{stop-tty-output} {fd/port} {no-value}
|
||||||
|
\defunx{start-tty-input} {fd/port} {no-value}
|
||||||
|
\defunx{stop-tty-input} {fd/port} {no-value}
|
||||||
|
\begin{desc}
|
||||||
|
These procedures can be used to control a terminal's input and output flow.
|
||||||
|
The \ex{stop-tty-output} and \ex{start-tty-output} procedures suspend
|
||||||
|
and resume output from a terminal device.
|
||||||
|
The \ex{stop-tty-input} and \ex{start-tty-input} procedures transmit
|
||||||
|
the special STOP and START characters to the terminal with the intention
|
||||||
|
of stopping and starting terminal input flow.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
% \defun {encode-baud-rate}{speed}{code}
|
||||||
|
% \defunx{decode-baud-rate}{code}{speed}
|
||||||
|
% \begin{desc}
|
||||||
|
% These procedures can be used to map between the special codes
|
||||||
|
% that are legal values for the \ex{tty-info:input-speed} and
|
||||||
|
% \ex{tty-info:output-speed} fields, and actual integer bits-per-second speeds.
|
||||||
|
% The codes are the values bound to the
|
||||||
|
% \ex{baud/4800}, \ex{baud/9600}, and other named constants defined above.
|
||||||
|
% For example:
|
||||||
|
% \begin{code}
|
||||||
|
% (decode-baud-rate baud/9600) {\evalto} 9600
|
||||||
|
%
|
||||||
|
% ;;; These two expressions are identical:
|
||||||
|
% (set-tty-info:input-speed ti baud/14400)
|
||||||
|
% (set-tty-info:input-speed ti (encode-baud-rate 14400))\end{code}
|
||||||
|
% \end{desc}
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
\subsection{Control terminals, sessions, and terminal process groups}
|
||||||
|
|
||||||
|
\defun{open-control-tty}{tty-name [flags]}{port}
|
||||||
|
\begin{desc}
|
||||||
|
This procedure opens terminal device \var{tty-name} as the process'
|
||||||
|
control terminal
|
||||||
|
(see the \ex{termios} man page for more information on control terminals).
|
||||||
|
The \var{tty-name} argument is a file-name such as \ex{/dev/ttya}.
|
||||||
|
The \var{flags} argument is a value suitable as the second argument
|
||||||
|
to the \ex{open-file} call; it defaults to \ex{open/read+write}, causing
|
||||||
|
the terminal to be opened for both input and output.
|
||||||
|
|
||||||
|
The port returned is an input port if the \var{flags} permit it,
|
||||||
|
otherwise an output port.
|
||||||
|
\R4RS/\scm/scsh do not have input/output ports,
|
||||||
|
so it's one or the other.
|
||||||
|
However, you can get both read and write ports open on a terminal
|
||||||
|
by opening it read/write, taking the result input port,
|
||||||
|
and duping it to an output port with \ex{dup->outport}.
|
||||||
|
|
||||||
|
This procedure guarantees to make the opened terminal the
|
||||||
|
process' control terminal only if the process does not have
|
||||||
|
an assigned control terminal at the time of the call.
|
||||||
|
If the scsh process already has a control terminal, the results are undefined.
|
||||||
|
|
||||||
|
To arrange for the process to have no control terminal prior to calling
|
||||||
|
this procedure, use the \ex{become-session-leader} procedure.
|
||||||
|
|
||||||
|
\oops{The control terminal code was added just before release time
|
||||||
|
for scsh release 0.4. Control terminals are one of the less-standardised
|
||||||
|
elements of Unix. We can't guarantee that the terminal is definitely
|
||||||
|
attached as a control terminal; we were only able to test this out
|
||||||
|
on HP-UX. If you intend to use this feature on your OS, you should
|
||||||
|
test it out first. If your OS requires the use of the \ex{TIOCSCTTY}
|
||||||
|
\ex{ioctl}, uncomment the appropriate few lines of code in the
|
||||||
|
file \ex{tty1.c} and send us email.}
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
\defun{become-session-leader}{}{\integer}
|
||||||
|
\begin{desc}
|
||||||
|
This is the C \ex{setsid()} call.
|
||||||
|
{\Posix} job-control has a three-level hierarchy:
|
||||||
|
session/process-group/process.
|
||||||
|
Every session has an associated control terminal.
|
||||||
|
This procedure places the current process into a brand new session,
|
||||||
|
and disassociates the process from any previous control terminal.
|
||||||
|
You may subsequently use \ex{open-control-tty} to open a new control
|
||||||
|
terminal.
|
||||||
|
|
||||||
|
It is an error to call this procedure if the current process is already
|
||||||
|
a process-group leader.
|
||||||
|
One way to guarantee this is not the case is only to call this procedure
|
||||||
|
after forking.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
|
||||||
|
\defun {tty-process-group}{fd/port}{\integer}
|
||||||
|
\defunx{set-tty-process-group}{fd/port pgrp}{\undefined}
|
||||||
|
\begin{desc}
|
||||||
|
This pair of procedures gets and sets the process group of a given
|
||||||
|
terminal.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
\subsection{Pseudo-terminals}
|
||||||
|
Scsh implements an interface to Berkeley-style pseudo-terminals.
|
||||||
|
|
||||||
|
\defun{fork-pty-session}{thunk}{[process pty-in pty-out tty-name]}
|
||||||
|
\begin{desc}
|
||||||
|
This procedure gives a convenient high-level interface to pseudo-terminals.
|
||||||
|
It first allocates a pty/tty pair of devices, and then forks a child
|
||||||
|
to execute procedure \var{thunk}.
|
||||||
|
In the child process
|
||||||
|
\begin{itemize}
|
||||||
|
\item Stdio and the current I/O ports are bound to the terminal device.
|
||||||
|
\item The child is placed in its own, new session
|
||||||
|
(see \ex{become\=session\=leader}).
|
||||||
|
\item The terminal device becomes the new session's controlling terminal
|
||||||
|
(see \ex{open-control-tty}).
|
||||||
|
\item The \ex{(error-output-port)} is unbuffered.
|
||||||
|
\end{itemize}
|
||||||
|
|
||||||
|
The \ex{fork-pty-session} procedure returns four values:
|
||||||
|
the child's process object, two ports open on the controlling pty device,
|
||||||
|
and the name of the child's corresponding terminal device.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
\defun{open-pty}{}{pty-inport tty-name}
|
||||||
|
\begin{desc}
|
||||||
|
This procedure finds a free pty/tty pair, and opens the pty device
|
||||||
|
with read/write access.
|
||||||
|
It returns a port on the pty,
|
||||||
|
and the name of the corresponding terminal device.
|
||||||
|
|
||||||
|
The port returned is an input port---Scheme doesn't allow input/output
|
||||||
|
ports.
|
||||||
|
However, you can easily use \ex{(dup->outport \var{pty-inport})}
|
||||||
|
to produce a matching output port.
|
||||||
|
You may wish to turn off I/O buffering for this output port.
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
|
||||||
|
\defun {pty-name->tty-name}{pty-name}{tty-name}
|
||||||
|
\defunx{tty-name->pty-name}{tty-name}{pty-name}
|
||||||
|
\begin{desc}
|
||||||
|
These two procedures map between corresponding terminal and pty controller
|
||||||
|
names.
|
||||||
|
For example,
|
||||||
|
\begin{code}
|
||||||
|
(pty-name->tty-name "/dev/ptyq3") {\evalto} "/dev/ttyq3"
|
||||||
|
(tty-name->pty-name "/dev/ttyrc") {\evalto} "/dev/ptyrc"\end{code}
|
||||||
|
|
||||||
|
\remark{This is rather Berkeley-specific. SVR4 ptys are rare enough that
|
||||||
|
I've no real idea if it generalises across the Unix gap. Experts
|
||||||
|
are invited to advise. Users feel free to not worry---the predominance
|
||||||
|
of current popular Unix systems use Berkeley ptys.}
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
\defunx{make-pty-generator}{}{\proc}
|
||||||
|
\begin{desc}
|
||||||
|
This procedure returns a generator of candidate pty names.
|
||||||
|
Each time the returned procedure is called, it produces a
|
||||||
|
new candidate.
|
||||||
|
Software that wishes to search through the set of available ptys
|
||||||
|
can use a pty generator to iterate over them.
|
||||||
|
After producing all the possible ptys, a generator returns {\sharpf}
|
||||||
|
every time it is called.
|
||||||
|
Example:
|
||||||
|
\begin{code}
|
||||||
|
(define pg (make-pty-generator))
|
||||||
|
(pg) {\evalto} "/dev/ptyp0"
|
||||||
|
(pg) {\evalto} "/dev/ptyp1"
|
||||||
|
\vdots
|
||||||
|
(pg) {\evalto} "/dev/ptyqe"
|
||||||
|
(pg) {\evalto} "/dev/ptyqf" \textit{(Last one)}
|
||||||
|
(pg) {\evalto} {\sharpf}
|
||||||
|
(pg) {\evalto} {\sharpf}
|
||||||
|
\vdots\end{code}
|
||||||
|
\end{desc}
|
||||||
|
|
||||||
|
|
||||||
|
% Flag tables
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
|
||||||
|
% Control-chars indices
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
\begin{table}[p]
|
||||||
|
\begin{center}
|
||||||
|
\begin{tabular}{|lll|} \hline
|
||||||
|
Scsh & C & Typical char \\
|
||||||
|
\hline\hline
|
||||||
|
{\Posix} & & \\
|
||||||
|
\exi{ttychar/delete-char} & \ex{ERASE} & del \\
|
||||||
|
\exi{ttychar/delete-line} & \ex{KILL} & \verb|^U| \\
|
||||||
|
\exi{ttychar/eof} & \ex{EOF} & \verb|^D| \\
|
||||||
|
\exi{ttychar/eol} & \ex{EOL} & \\
|
||||||
|
\exi{ttychar/interrupt} & \ex{INTR} & \verb|^C| \\
|
||||||
|
\exi{ttychar/quit} & \ex{QUIT} & \verb|^\| \\
|
||||||
|
\exi{ttychar/suspend} & \ex{SUSP} & \verb|^Z| \\
|
||||||
|
\exi{ttychar/start} & \ex{START} & \verb|^Q| \\
|
||||||
|
\exi{ttychar/stop} & \ex{STOP} & \verb|^S| \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
{SVR4 and 4.3+BSD} & & \\
|
||||||
|
\exi{ttychar/delayed-suspend} & \ex{DSUSP} & \verb|^Y| \\
|
||||||
|
\exi{ttychar/delete-word} & \ex{WERASE} & \verb|^W| \\
|
||||||
|
\exi{ttychar/discard} & \ex{DISCARD} & \verb|^O| \\
|
||||||
|
\exi{ttychar/eol2} & \ex{EOL2} & \\
|
||||||
|
\exi{ttychar/literal-next} & \ex{LNEXT} & \verb|^V| \\
|
||||||
|
\exi{ttychar/reprint} & \ex{REPRINT} & \verb|^R| \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
{4.3+BSD} & & \\
|
||||||
|
\exi{ttychar/status} & \ex{STATUS} & \verb|^T| \\
|
||||||
|
\hline
|
||||||
|
\end{tabular}
|
||||||
|
\end{center}
|
||||||
|
\caption{Indices into the \protect\ex{tty-info} record's
|
||||||
|
\protect\var{control-chars} string,
|
||||||
|
and the character traditionally found at each index.
|
||||||
|
Only the indices for the {\Posix} entries are guaranteed to
|
||||||
|
be non-\sharpf.}
|
||||||
|
\label{table:ttychars}
|
||||||
|
\end{table}
|
||||||
|
|
||||||
|
% Input flags
|
||||||
|
%%%%%%%%%%%%%
|
||||||
|
\begin{table}[p]
|
||||||
|
\begin{center}\small
|
||||||
|
\begin{tabular}{|lll|} \hline
|
||||||
|
Scsh & C & Meaning \\
|
||||||
|
\hline\hline
|
||||||
|
\Posix & & \\
|
||||||
|
\exi{ttyin/check-parity}
|
||||||
|
& \ex{INPCK} & Check parity. \\
|
||||||
|
\exi{ttyin/ignore-bad-parity-chars}
|
||||||
|
& \ex{IGNPAR} & Ignore chars with parity errors. \\
|
||||||
|
\exi{ttyin/mark-parity-errors}
|
||||||
|
& \ex{PARMRK} & Insert chars to mark parity errors.\\
|
||||||
|
\exi{ttyin/ignore-break}
|
||||||
|
& \ex{IGNBRK} & Ignore breaks. \\
|
||||||
|
\exi{ttyin/interrupt-on-break}
|
||||||
|
& \ex{BRKINT} & Signal on breaks. \\
|
||||||
|
\exi{ttyin/7bits}
|
||||||
|
& \ex{ISTRIP} & Strip char to seven bits. \\
|
||||||
|
\exi{ttyin/cr->nl}
|
||||||
|
& \ex{ICRNL} & Map carriage-return to newline. \\
|
||||||
|
\exi{ttyin/ignore-cr}
|
||||||
|
& \ex{IGNCR} & Ignore carriage-returns. \\
|
||||||
|
\exi{ttyin/nl->cr}
|
||||||
|
& \ex{INLCR} & Map newline to carriage-return. \\
|
||||||
|
\exi{ttyin/input-flow-ctl}
|
||||||
|
& \ex{IXOFF} & Enable input flow control. \\
|
||||||
|
\exi{ttyin/output-flow-ctl}
|
||||||
|
& \ex{IXON} & Enable output flow control. \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
{SVR4 and 4.3+BSD} & & \\
|
||||||
|
\exi{ttyin/xon-any} & \ex{IXANY} & Any char restarts after stop. \\
|
||||||
|
\exi{ttyin/beep-on-overflow} & \ex{IMAXBEL} & Ring bell when queue full. \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
{SVR4} & & \\
|
||||||
|
\exi{ttyin/lowercase} & \ex{IUCLC} & Map upper case to lower case. \\
|
||||||
|
\hline
|
||||||
|
\end{tabular}
|
||||||
|
\end{center}
|
||||||
|
\caption{Input-flags. These are the named flags for the \protect\ex{tty-info}
|
||||||
|
record's \protect\var{input-flags} field.
|
||||||
|
These flags generally control the processing of input chars.
|
||||||
|
Only the {\Posix} entries are guaranteed to be non-\sharpf.
|
||||||
|
}
|
||||||
|
\label{table:ttyin}
|
||||||
|
\end{table}
|
||||||
|
|
||||||
|
% Output flags
|
||||||
|
%%%%%%%%%%%%%%
|
||||||
|
\begin{table}[p]
|
||||||
|
\begin{center}%\small
|
||||||
|
\begin{tabular}{|lll|} \hline
|
||||||
|
Scsh & C & Meaning \\ \hline\hline
|
||||||
|
|
||||||
|
\multicolumn{3}{|l|}{\Posix} \\
|
||||||
|
\exi{ttyout/enable} & \ex{OPOST} & Enable output processing. \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
\multicolumn{3}{|l|}{SVR4 and 4.3+BSD} \\
|
||||||
|
\exi{ttyout/nl->crnl} & \ex{ONLCR} & Map nl to cr-nl. \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
\multicolumn{3}{|l|}{4.3+BSD} \\
|
||||||
|
\exi{ttyout/discard-eot} & \ex{ONOEOT} & Discard EOT chars. \\
|
||||||
|
\exi{ttyout/expand-tabs} & \ex{OXTABS}\footnote{
|
||||||
|
Note this is distinct from the SVR4-equivalent
|
||||||
|
\ex{ttyout/tab-delayx} flag defined in
|
||||||
|
table~\ref{table:ttydelays}.}
|
||||||
|
& Expand tabs. \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
\multicolumn{3}{|l|}{SVR4} \\
|
||||||
|
\exi{ttyout/cr->nl} & \ex{OCRNL} & Map cr to nl. \\
|
||||||
|
\exi{ttyout/nl-does-cr} & \ex{ONLRET}& Nl performs cr as well. \\
|
||||||
|
\exi{ttyout/no-col0-cr} & \ex{ONOCR} & No cr output in column 0. \\
|
||||||
|
\exi{ttyout/delay-w/fill-char} & \ex{OFILL} & Send fill char to delay. \\
|
||||||
|
\exi{ttyout/fill-w/del} & \ex{OFDEL} & Fill char is {\Ascii} DEL. \\
|
||||||
|
\exi{ttyout/uppercase} & \ex{OLCUC} & Map lower to upper case. \\
|
||||||
|
\hline
|
||||||
|
\end{tabular}
|
||||||
|
\end{center}
|
||||||
|
\caption{Output-flags. These are the named flags for the \protect\ex{tty-info}
|
||||||
|
record's \protect\var{output-flags} field.
|
||||||
|
These flags generally control the processing of output chars.
|
||||||
|
Only the {\Posix} entries are guaranteed to be non-\sharpf.}
|
||||||
|
\label{table:ttyout}
|
||||||
|
\end{table}
|
||||||
|
|
||||||
|
% Delay flags
|
||||||
|
%%%%%%%%%%%%%
|
||||||
|
\begin{table}[p]
|
||||||
|
\begin{tabular}{r|ll|} \cline{2-3}
|
||||||
|
& Value & Comment \\ \cline{2-3}
|
||||||
|
{Backspace delay} & \exi{ttyout/bs-delay} & Bit-field mask \\
|
||||||
|
& \exi{ttyout/bs-delay0} & \\
|
||||||
|
& \exi{ttyout/bs-delay1} & \\
|
||||||
|
|
||||||
|
\cline{2-3}
|
||||||
|
{Carriage-return delay} & \exi{ttyout/cr-delay} & Bit-field mask \\
|
||||||
|
& \exi{ttyout/cr-delay0} & \\
|
||||||
|
& \exi{ttyout/cr-delay1} & \\
|
||||||
|
& \exi{ttyout/cr-delay2} & \\
|
||||||
|
& \exi{ttyout/cr-delay3} & \\
|
||||||
|
|
||||||
|
\cline{2-3}
|
||||||
|
{Form-feed delay} & \exi{ttyout/ff-delay} & Bit-field mask \\
|
||||||
|
& \exi{ttyout/ff-delay0} & \\
|
||||||
|
& \exi{ttyout/ff-delay1} & \\
|
||||||
|
|
||||||
|
\cline{2-3}
|
||||||
|
{Horizontal-tab delay} & \exi{ttyout/tab-delay} & Bit-field mask \\
|
||||||
|
& \exi{ttyout/tab-delay0} & \\
|
||||||
|
& \exi{ttyout/tab-delay1} & \\
|
||||||
|
& \exi{ttyout/tab-delay2} & \\
|
||||||
|
& \exi{ttyout/tab-delayx} & Expand tabs \\
|
||||||
|
|
||||||
|
\cline{2-3}
|
||||||
|
{Newline delay} & \exi{ttyout/nl-delay} & Bit-field mask \\
|
||||||
|
& \exi{ttyout/nl-delay0} & \\
|
||||||
|
& \exi{ttyout/nl-delay1} & \\
|
||||||
|
|
||||||
|
\cline{2-3}
|
||||||
|
{Vertical tab delay} & \exi{ttyout/vtab-delay} & Bit-field mask \\
|
||||||
|
& \exi{ttyout/vtab-delay0} & \\
|
||||||
|
& \exi{ttyout/vtab-delay1} & \\
|
||||||
|
|
||||||
|
\cline{2-3}
|
||||||
|
{All} & \exi{ttyout/all-delay} & Total bit-field mask \\
|
||||||
|
\cline{2-3}
|
||||||
|
\end{tabular}
|
||||||
|
|
||||||
|
\caption{Delay constants. These are the named flags for the
|
||||||
|
\protect\ex{tty-info} record's \protect\var{output-flags} field.
|
||||||
|
These flags control the output delays associated with printing
|
||||||
|
special characters.
|
||||||
|
They are non-{\Posix}, and have non-{\sharpf} values
|
||||||
|
only on SVR4 systems.}
|
||||||
|
\label{table:ttydelays}
|
||||||
|
\end{table}
|
||||||
|
|
||||||
|
% Control flags
|
||||||
|
%%%%%%%%%%%%%%%
|
||||||
|
\begin{table}[p]
|
||||||
|
\begin{center}%\small
|
||||||
|
\begin{tabular}{|lll|} \hline
|
||||||
|
Scsh & C & Meaning \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
\multicolumn{3}{|l|}{\Posix} \\
|
||||||
|
\exi{ttyc/char-size} & \ex{CSIZE} & Character size mask \\
|
||||||
|
\exi{ttyc/char-size5} & \ex{CS5} & 5 bits \\
|
||||||
|
\exi{ttyc/char-size6} & \ex{CS6} & 6 bits \\
|
||||||
|
\exi{ttyc/char-size7} & \ex{CS7} & 7 bits \\
|
||||||
|
\exi{ttyc/char-size8} & \ex{CS8} & 8 bits \\
|
||||||
|
\exi{ttyc/enable-parity}& \ex{PARENB} & Generate and detect parity. \\
|
||||||
|
\exi{ttyc/odd-parity} & \ex{PARODD} & Odd parity. \\
|
||||||
|
\exi{ttyc/enable-read} & \ex{CREAD} & Enable reception of chars. \\
|
||||||
|
\exi{ttyc/hup-on-close} & \ex{HUPCL} & Hang up on last close. \\
|
||||||
|
\exi{ttyc/no-modem-sync}& \ex{LOCAL} & Ignore modem lines. \\
|
||||||
|
\exi{ttyc/2-stop-bits} & \ex{CSTOPB} & Send two stop bits. \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
\multicolumn{3}{|l|}{4.3+BSD} \\
|
||||||
|
\exi{ttyc/ignore-flags} & \ex{CIGNORE} & Ignore control flags. \\
|
||||||
|
\exi{ttyc/CTS-output-flow-ctl} & \verb|CCTS_OFLOW| & CTS flow control of output \\
|
||||||
|
\exi{ttyc/RTS-input-flow-ctl} & \verb|CRTS_IFLOW| & RTS flow control of input \\
|
||||||
|
\exi{ttyc/carrier-flow-ctl} & \ex{MDMBUF} & \\
|
||||||
|
\hline
|
||||||
|
\end{tabular}
|
||||||
|
\end{center}
|
||||||
|
|
||||||
|
\caption{Control-flags. These are the named flags for the \protect\ex{tty-info}
|
||||||
|
record's \protect\var{control-flags} field.
|
||||||
|
These flags generally control the details of the terminal's
|
||||||
|
serial line.
|
||||||
|
Only the {\Posix} entries are guaranteed to be non-\sharpf.}
|
||||||
|
\label{table:ttyctl}
|
||||||
|
\end{table}
|
||||||
|
|
||||||
|
% Local flags
|
||||||
|
%%%%%%%%%%%%%
|
||||||
|
\begin{table}[p]
|
||||||
|
\begin{center}\small
|
||||||
|
\begin{tabular}{|lll|} \hline
|
||||||
|
Scsh & C & Meaning \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
\multicolumn{3}{|l|}{\Posix} \\
|
||||||
|
\exi{ttyl/canonical} & \ex{ICANON} & Canonical input processing. \\
|
||||||
|
\exi{ttyl/echo} & \ex{ECHO} & Enable echoing. \\
|
||||||
|
\exi{ttyl/echo-delete-line} & \ex{ECHOK} & Echo newline after line kill. \\
|
||||||
|
\exi{ttyl/echo-nl} & \ex{ECHONL} & Echo newline even if echo is off. \\
|
||||||
|
\exi{ttyl/visual-delete}& \ex{ECHOE} & Visually erase chars. \\
|
||||||
|
\exi{ttyl/enable-signals} & \ex{ISIG} & Enable \verb|^|C, \verb|^|Z signalling. \\
|
||||||
|
\exi{ttyl/extended} & \ex{IEXTEN} & Enable extensions. \\
|
||||||
|
\exi{ttyl/no-flush-on-interrupt}
|
||||||
|
& \ex{NOFLSH} & Don't flush after interrupt. \\
|
||||||
|
\exi{ttyl/ttou-signal} & \ex{ITOSTOP} & \ex{SIGTTOU} on background output. \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
\multicolumn{3}{|l|}{SVR4 and 4.3+BSD} \\
|
||||||
|
\exi{ttyl/echo-ctl} & \ex{ECHOCTL}
|
||||||
|
& Echo control chars as ``\verb|^X|''. \\
|
||||||
|
\exi{ttyl/flush-output} & \ex{FLUSHO} & Output is being flushed. \\
|
||||||
|
\exi{ttyl/hardcopy-delete} & \ex{ECHOPRT} & Visual erase for hardcopy. \\
|
||||||
|
\exi{ttyl/reprint-unread-chars} & \ex{PENDIN} & Retype pending input. \\
|
||||||
|
\exi{ttyl/visual-delete-line} & \ex{ECHOKE} & Visually erase a line-kill. \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
\multicolumn{3}{|l|}{4.3+BSD} \\
|
||||||
|
\exi{ttyl/alt-delete-word} & \ex{ALTWERASE} & Alternate word erase algorithm \\
|
||||||
|
\exi{ttyl/no-kernel-status} & \ex{NOKERNINFO} & No kernel status on \verb|^T|. \\
|
||||||
|
|
||||||
|
\hline\hline
|
||||||
|
\multicolumn{3}{|l|}{SVR4} \\
|
||||||
|
\exi{ttyl/case-map} & \ex{XCASE} & Canonical case presentation \\
|
||||||
|
\hline
|
||||||
|
\end{tabular}
|
||||||
|
\end{center}
|
||||||
|
|
||||||
|
\caption{Local-flags. These are the named flags for the \protect\ex{tty-info}
|
||||||
|
record's \protect\var{local-flags} field.
|
||||||
|
These flags generally control the details of the line-editting
|
||||||
|
user interface.
|
||||||
|
Only the {\Posix} entries are guaranteed to be non-\sharpf.}
|
||||||
|
\label{table:ttylocal}
|
||||||
|
\end{table}
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
|
@ -0,0 +1,38 @@
|
||||||
|
%&latex -*- latex -*-
|
||||||
|
|
||||||
|
% This is the reference manual for the Scheme Shell.
|
||||||
|
|
||||||
|
\documentclass[twoside]{report}
|
||||||
|
\usepackage{code,boxedminipage,draftfooters,makeidx,palatino,ct,
|
||||||
|
headings,mantitle,array,matter,mysize10,a4wide}
|
||||||
|
|
||||||
|
% Style issues
|
||||||
|
\parskip = 3pt plus 3pt
|
||||||
|
\sloppy
|
||||||
|
|
||||||
|
\input{decls}
|
||||||
|
\makeindex
|
||||||
|
%%% End preamble
|
||||||
|
|
||||||
|
\begin{document}
|
||||||
|
|
||||||
|
\frontmatter
|
||||||
|
\include{front}
|
||||||
|
|
||||||
|
\mainmatter
|
||||||
|
\include{intro}
|
||||||
|
\include{procnotation}
|
||||||
|
\include{syscalls}
|
||||||
|
\include{network}
|
||||||
|
\include{strings}
|
||||||
|
\include{rdelim}
|
||||||
|
\include{awk}
|
||||||
|
\include{miscprocs}
|
||||||
|
\include{running}
|
||||||
|
\include{changes}
|
||||||
|
\include{todo}
|
||||||
|
|
||||||
|
\backmatter
|
||||||
|
\printindex
|
||||||
|
|
||||||
|
\end{document}
|
||||||
Loading…
Reference in New Issue