256 lines
9.1 KiB
Plaintext
256 lines
9.1 KiB
Plaintext
Scsh 0.6.0 Release notes -*- outline -*-
|
|
|
|
We are pleased to release scsh version 0.6.0. The new release is
|
|
based on a newer version of Scheme 48 than the previous releases. The
|
|
update of the underlying system is a massive switch and provides many
|
|
new features, most notably a sophisticated thread system. We tried to
|
|
make as less changes as possible to the API, see Section "API changes"
|
|
for details. Unfortunately, due to the number of changes that were
|
|
necessary to the internal structures, this release will probably
|
|
contain some bugs. Don't hesitate to report bugs, we rely on your feedback!
|
|
|
|
The text below gives a general description of scsh, instructions for obtaining
|
|
it, pointers to discussion forums, and a description of the new features in
|
|
release 0.6.0. (Emacs should display this document is in outline mode. Say
|
|
c-h m for instructions on how to move through it by sections (e.g., c-c c-n,
|
|
c-c c-p).)
|
|
|
|
* Contents
|
|
==========
|
|
What is scsh
|
|
Scsh as a scripting language
|
|
Scsh as a systems-programming language
|
|
Scsh is a portable programming environment
|
|
Obtaining and installing scsh
|
|
Getting in touch
|
|
The World-Wide What?
|
|
New in this release
|
|
Scsh is now based on Scheme 48 0.53
|
|
Interface to dot-locking, crypt and syslog
|
|
API changes
|
|
Bugfixes
|
|
Thanks
|
|
|
|
|
|
* What is scsh
|
|
==============
|
|
Scsh is a broad-spectrum systems-programming environment for Unix embedded
|
|
in R5RS Scheme. It has an open-source copyright, and runs on most major
|
|
Unix systems.
|
|
|
|
** Scsh as a scripting language
|
|
-------------------------------
|
|
Scsh has a high-level process notation for doing shell-script like tasks:
|
|
running programs, establishing pipelines and I/O redirection. For example, the
|
|
shell pipeline
|
|
|
|
gunzip < paper.tex.gz | detex | spell | lpr -Ppulp &
|
|
|
|
would be written in scsh as
|
|
|
|
(& (| (gunzip) (detex) (spell) (lpr -Ppulp)) ; Background a pipeline
|
|
(< paper.tex.gz)) ; with this redirection
|
|
|
|
Scsh embeds this process notation within a full Scheme implementation.
|
|
The process notation is realized as a set of macro definitions, and is
|
|
carefully designed to allow full integration with standard Scheme code.
|
|
Scsh isn't Scheme-like; it is Scheme.
|
|
|
|
At the scripting level, scsh also has an Awk design, also implemented
|
|
as a macro that can be embedded inside general Scheme code.
|
|
|
|
Scripts can be written as standalone Scheme source files, with a leading
|
|
#!/usr/local/bin/scsh -s
|
|
trigger line.
|
|
|
|
|
|
** Scsh as a systems-programming language
|
|
-----------------------------------------
|
|
Scsh additionally provides the low-level access to the operating system
|
|
normally associated with C. The current release provides full access to Posix,
|
|
plus important non-Posix extensions, such as complete sockets support.
|
|
"Complete Posix" means: fork, exec & wait, sockets, full read, write, open &
|
|
close, seek & tell, complete file-system access, including stat,
|
|
chmod/chgrp/chown, symlink, FIFO & directory access, tty & pty support, file
|
|
locking, pipes, select, file-name pattern-matching, time & date, environment
|
|
variables, signal handlers, and more.
|
|
|
|
In brief, you can now write Unix systems programs in Scheme instead of C.
|
|
For example, we have implemented an extensible HTTP server at MIT entirely
|
|
in scsh.
|
|
|
|
As important as full access to the OS is the manner in which it is provided.
|
|
Scsh integrates the OS support into Scheme in a manner which respects the
|
|
general structure of the language. The details of the design are discussed
|
|
in a joint MIT Lab for Computer Science/University of Hong Kong technical
|
|
report, "A Scheme Shell," also to appear in a revised format in the *Journal
|
|
of Lisp and Symbolic Computation." This paper is also available by ftp:
|
|
ftp://ftp-swiss.ai.mit.edu/pub/su/scsh/scsh-paper.ps
|
|
|
|
|
|
** Scsh is a portable programming environment
|
|
---------------------------------------------
|
|
Scsh is designed for portability. It is implemented on top of Scheme 48,
|
|
a byte-code-interpreter Scheme implementation. The Scheme 48 virtual machine
|
|
can be compiled on any system with a C compiler; the rest of Scheme 48 is
|
|
machine-independent across 32-bit processors. Scsh's OS interface is
|
|
also quite portable, providing a consistent interface across different
|
|
Unix platforms. We currently have scsh implementations for:
|
|
AIX
|
|
BSD/OS
|
|
CXUX
|
|
FreeBSD
|
|
HP-UX
|
|
IRIX
|
|
Linux
|
|
NetBSD
|
|
Solaris
|
|
SunOS
|
|
Ultrix
|
|
Win32
|
|
Darwin/Mac OS X
|
|
|
|
Scsh code should run without change across these systems.
|
|
Porting to new platforms is usually not difficult.
|
|
|
|
|
|
* Obtaining and installing scsh
|
|
===============================
|
|
You can get a copy of scsh via anonymous ftp, from
|
|
ftp://ftp-swiss.ai.mit.edu/pub/su/scsh/scsh.tar.gz
|
|
The tar file includes a detailed manual and a paper describing
|
|
the design of the system.
|
|
|
|
For the lazily curious, we also have the manual separately available as
|
|
ftp://ftp-swiss.ai.mit.edu/pub/su/scsh/scsh-manual.ps
|
|
Just click 'n view.
|
|
|
|
You *should* be able to build scsh on the standard platforms with exactly five
|
|
commands: gunzip, tar, cd, ./configure, and make. The configure script figures
|
|
out the special flags and switches needed to make the build work (thanks to
|
|
the GNU project for the autoconfig tool that makes this possible).
|
|
|
|
After doing the make, you can start up a Scheme shell and try it out
|
|
by saying
|
|
./go
|
|
See the manual for full details on the command-line switches.
|
|
|
|
If it's harder than this, and your system is standard, we'd like to know
|
|
about it.
|
|
|
|
|
|
* Getting in touch
|
|
==================
|
|
There are two main ways to join in scsh-related discussion: the mailing-list
|
|
scsh@zurich.ai.mit.edu
|
|
and the netnews group
|
|
comp.lang.scheme.scsh
|
|
These two forums should be equivalent, being bi-directionally gatewayed
|
|
at MIT, but due to technical problems it's better to read them both.
|
|
|
|
Bugs can be reported to
|
|
scsh-bugs@zurich.ai.mit.edu
|
|
or via the Scsh project's bugs section on SourceForge:
|
|
http://sourceforge.net/projects/scsh/
|
|
|
|
If you do not netnews hierarchy, or wish to join the mailing
|
|
list for other reasons, send mail to
|
|
scsh-request@zurich.ai.mit.edu
|
|
|
|
|
|
* The World-Wide What?
|
|
======================
|
|
We even have one of those dot-com cyberweb things:
|
|
http://www.scsh.net
|
|
We now manage the project using SourceForge:
|
|
http://sourceforge.net/projects/scsh/
|
|
|
|
* New in this release
|
|
====================
|
|
|
|
** Scsh is now based on Scheme 48 0.53
|
|
With the move from Scheme 48 version 0.36 to version 0.53 in this
|
|
release the underlying system received a massive update. The most
|
|
significant changes include:
|
|
User level threads
|
|
Advanced garbage collector
|
|
Improved foreign function interface to C
|
|
|
|
The most significant change for Scsh users is the addition of a
|
|
user-level thread system. Scsh provides various features to deal
|
|
with this new power in a system programming environment: An event
|
|
based interface to interrupts, thread local process state and
|
|
thread-safe system calls.
|
|
|
|
** A manual for Scheme 48 has been included
|
|
Richard Kelsey, the author of Scheme 48, has graciously allowed us
|
|
to retrofit the current Scheme 48 manual for inclusion in this scsh
|
|
release.
|
|
|
|
** Interface to dot-locking, crypt and syslog
|
|
Scsh now provides advisory file locking via the dot-locking scheme
|
|
and a direct binding to the crypt function. Furthermore we added
|
|
a complete, system-independent and thread-safe interface to syslog.
|
|
|
|
** API changes
|
|
Some features of the previous releases are currently not
|
|
supported as we did not have the time to implement them. Please tell
|
|
us, if you can't get along without them. Here is a listing of these
|
|
currently dereleased features:
|
|
select
|
|
select!
|
|
ODBC support
|
|
bufpol/line
|
|
|
|
The following procedures received new names in this release:
|
|
sleep (now process-sleep)
|
|
sleep-until (now process-sleep-until)
|
|
|
|
network-info, service-info and protocol-info now return #f on non-success.
|
|
|
|
The default directory for creating temporary files has changed: It's
|
|
now the value of $TMPDIR if set and /var/tmp otherwise.
|
|
|
|
The nth procedure is still there but is now officially obsolete. It
|
|
will go away in a future release.
|
|
|
|
** HTML version of the manual
|
|
There is now a HTML version of the scsh manual generated by tex2page
|
|
|
|
** Bugfixes
|
|
Most of the known bugs of version 0.5.3 have been fixed. See the
|
|
project page on SourceForge for a list of the remaining known bugs.
|
|
|
|
|
|
* Thanks
|
|
========
|
|
|
|
We would like to thank the members of local-resistance cells for the
|
|
Underground everywhere for bug reports, bug fixes, design review and comments
|
|
that were incorporated into this release. We really appreciate their help,
|
|
particularly in the task of porting scsh to new platforms.
|
|
Friedrich Dominicus
|
|
Jay Nietling
|
|
Tim Bradshaw
|
|
Robert Brown
|
|
Eric Marsden
|
|
Paul Emsley
|
|
Pawel Turnau
|
|
Hannu Koivisto
|
|
Andy Gaynor
|
|
Francisco Vides Fernandez
|
|
Tim Burgess
|
|
Brian Denheyer
|
|
Harvey Stein
|
|
Eric Hilsdale
|
|
Andreas Bernauer
|
|
Reini Urban
|
|
|
|
We'd like to thank everyone else for their patience; we are sorry that
|
|
it took more than two years from the start of the port to this release.
|
|
|
|
Brought to you by the Scheme Underground. Go forth and write elegant systems
|
|
programs.
|
|
-Olin Shivers, Brian Carlstrom, Martin Gasbichler & Mike Sperber
|
|
|