700 lines
22 KiB
HTML
700 lines
22 KiB
HTML
<html>
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<head>
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<!-- This file has been generated by unroff 1.0, 03/21/96 19:29:17. -->
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<!-- Do not edit! -->
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<link rev="made" href="mailto:net@informatik.uni-bremen.de">
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<!-- $Revision: 1.16 $ -->
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<title>Manual page for unroff(1)</title>
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</head>
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<body>
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<h2>
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unroff - programmable, extensible troff translator
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<hr></h2>
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<h2>SYNOPSIS</h2>
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<b>unroff
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</b>[
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<b>-f</b><i>format
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</i>] [
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<b>-m</b><i>package
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</i>] [
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<b>-h</b><i>heapsize
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</i>] [
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<b>-C
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</b>]
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[
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<b>-t
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</b>] [
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<i>file</i> | <i>option...
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</i>]
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<h2>OVERVIEW</h2>
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<i>unroff
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</i>reads and parses documents with embedded troff markup
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and translates them to a different format--typically
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to a different markup language such as SGML.<tt> </tt>
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The actual output format is not hard-wired into
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<i>unroff</i>;
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instead, the translation is performed by a set of user-supplied rules
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and functions written in the
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<i>Scheme
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</i>programming language.<tt> </tt>
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<i>unroff
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</i>employs the Extension Language Kit
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<i>Elk
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</i>to achieve programmability based on the Scheme language:
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a fully-functional Scheme interpreter is embedded in the translator.<tt> </tt>
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<p>
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The documents that can be processed by
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<i>unroff
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</i>are not restricted to a specific troff macro set.<tt> </tt>
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Translation rules for a new macro package can be added by supplying
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a set of corresponding Scheme procedures (a ``back-end'').<tt> </tt>
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Predefined sets of such procedures exist for a number of combinations
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of target language and troff macro package:
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<i>unroff
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</i>1.0 supports translation to the ``Hypertext Markup Language''
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(HTML) version 2.0 for the
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<b>-man
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</b>and
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<b>-ms
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</b>macro packages as well as ``bare'' troff (see
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<b>unroff-html</b>(1),
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<b>unroff-html-man</b>(1),
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and
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<b>unroff-html-ms</b>(1)
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for a description).<tt> </tt>
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<p>
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Unlike conventional troff conversion tools,
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<i>unroff
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</i>includes a full troff parser and can therefore handle user-defined
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macros, strings, and number registers, nested if-else requests
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(with text blocks enclosed by `\{' and `\}' escape sequences), arbitrary
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fonts and font positions, troff ``copy mode'', low-level formatting
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requests such as `\l' and '\h', and the subtle
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differences between request and macro invocations that are inherent
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in the troff processing model.<tt> </tt>
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<i>unroff
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</i>has adopted a number of troff extensions introduced by
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<i>groff</i>,
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among them long names for macros, strings, number registers, and
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special characters, and the `\$@' and `\$*' escape sequences.<tt> </tt>
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<p>
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<i>unroff
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</i>interprets its input stream as a sequence of ``events''.<tt> </tt>
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Events include the invocation of a troff request or macro, the use of a
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troff escape sequence or special character, a troff string
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or number register reference, end of sentence, start
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of a new input file, and so on.<tt> </tt>
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For each event encountered
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<i>unroff
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</i>invokes a Scheme procedure associated with that event.<tt> </tt>
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Some types of events require a procedure that returns a string (or an
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object that can be coerced into a string),
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which is then interpolated into the input or output stream;
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for other types of events, the event procedures are just called
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for their side-effects.<tt> </tt>
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<p>
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The set of Scheme procedures to be used by
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<i>unroff
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</i>is determined by the output format and the name of the troff
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macro package.<tt> </tt>
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In addition, users can supply event procedures for their own macro
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definitions (or replace existing ones) in form of a simple Scheme
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program passed to
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<i>unroff
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</i>along with the troff input files; Scheme code can even be directly
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embedded in the troff input as described below.<tt> </tt>
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<p>
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The full capabilities of
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<i>unroff
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</i>and the Scheme primitives required to write extensions or support
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for new output formats are described in the
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<i>Unroff Programmer's Manual</i>.<tt> </tt>
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<h2>GENERIC OPTIONS</h2>
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<dl>
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<dt><b>-f</b><i>format
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</i><dd>
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Specifies the output format into which the troff input files are
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translated.<tt> </tt>
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If no
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<b>-f
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</b>option is given, a default output format is used (for
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<i>unroff
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</i>version 1.0 the default is
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<b>-f</b><i>html</i>).<tt> </tt>
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This default can be overridden by setting the
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<b>UNROFF_FORMAT
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</b>environment variable.<tt> </tt>
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<dt><b>-m</b><i>name
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</i><dd>
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Specifies the name of the macro package that would be used by ordinary
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troff to typeset the document.<tt> </tt>
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In contrast to troff
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<i>unroff
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</i>does not actually load the macro package.<tt> </tt>
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Instead, the specified name-in combination with the specified output
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format-selects a set of Scheme files providing the procedure definitions
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that control the translation process (see
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<b>FILES
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</b>below).<tt> </tt>
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Therefore a corresponding
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<b>tmac
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</b>file need not exist for a given
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<b>-m
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</b>option.<tt> </tt>
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<dt><b>-h</b><i>heapsize
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</i><dd>
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This option can be used to specify a non-standard heap size (in Kbytes)
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for the Scheme interpreter included in
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<i>unroff</i>;
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see
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<b>elk</b>(1).<tt> </tt>
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<dt><b>-C
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</b><dd>
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Enables troff compatibility mode.<tt> </tt>
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In compatibility mode certain
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<i>groff
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</i>extensions such as long names are not recognized.<tt> </tt>
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<dt><b>-t
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</b><dd>
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Enables test mode.<tt> </tt>
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Instead of processing troff input files,
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<i>unroff
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</i>enters an interactive Scheme top-level.<tt> </tt>
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This can be useful to interactively experiment with the Scheme
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primitives defined by
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<i>unroff
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</i>or to test or debug user-defined Scheme procedures.<tt> </tt>
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</dl>
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<h2>KEYWORD/VALUE OPTIONS</h2>
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In addition to the generic options, a set of output-format-specific
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options can be set from the command line and from within troff and
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Scheme input files.<tt> </tt>
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When specified on the command line, these options have the form
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<dl><dt><dd>
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<pre>
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<i>option</i>=<i>value</i>
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</pre>
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</dl>
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where the format of
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<i>value
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</i>depends on the
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<i>type
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</i>of the option.<tt> </tt>
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For example, most output formats defines an option
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<b>document
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</b>whose value is used as a prefix for all output files created during
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the translation.<tt> </tt>
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The option is assigned a value by specifying a token such as
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<dl><dt><dd>
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<pre>
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document=thesis
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</pre>
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</dl>
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on the command line.<tt> </tt>
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This option's value is interpreted as a plain string, i.e.
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its type is
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<b>string</b>.<tt> </tt>
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<p>
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The Scheme back-ends and user-supplied extensions can define their
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own option types, but at least the following types are recognized:
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<dl>
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<dt><b>integer
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</b><dd>
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the option value is composed of an optional sign and an (arbitrary)
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string of digits
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<dt><b>boolean
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</b><dd>
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the option value must either be the character 1 (true) or the
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character 0 (false)
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<dt><b>character
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</b><dd>
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a single character must be specified as the option value
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<dt><b>string
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</b><dd>
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an arbitrary string of characters can be specified
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<dt><b>dynstring
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</b><dd>
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``dynamic string''; the option value is either
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</dl>
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<dl><dt><dd>
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<dl>
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<dt><i>string
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</i><dd>
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to assign a string to the option in the normal way, or
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<dt><b>+</b><i>string
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</i><dd>
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to append the characters after the plus sign
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to the option's current value, or
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<dt><b>-</b><i>string
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</i><dd>
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to remove the characters after the minus sign from the
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option's current value.<tt> </tt>
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</dl>
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</dl>
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<p>
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These extension-specific options must appear after the generic
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<i>unroff
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</i>options and may be mixed with the file name arguments.<tt> </tt>
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As the option assignments and specified input files are processed in
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order, the value given for an option is in effect for all the input
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files that appear on the command line to the right of the option.<tt> </tt>
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<p>
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The exact set of keyword/value options is determined by the
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Scheme code loaded for a given combination of output format
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and macro package name and is described in the corresponding
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manuals.<tt> </tt>
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The following few options can always be set, regardless of the
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actual output format:
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<dl>
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<dt><b>include-files</b> (boolean)
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<dd>
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If true,
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<b>.so
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</b>requests are executed by
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<i>unroff
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</i>in the normal way (that is, the named input file is read and
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parsed), otherwise
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<b>.so
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</b>requests are ignored.<tt> </tt>
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The default value is 1.<tt> </tt>
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<dt><b>if-true</b> (dynstring)
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<dd>
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the specified characters are assigned to (appended to, removed from)
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the set of one-character conditions that are regarded as true
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by the
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<b>.if
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</b>and
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<b>.ie
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</b>requests.<tt> </tt>
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The default value is "to".<tt> </tt>
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<dt><b>if-false</b> (dynstring)
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<dd>
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like
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<b>if-true</b>;
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specifies the one-character conditions regarded as false.<tt> </tt>
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The default value is "ne".<tt> </tt>
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</dl>
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<h2>FILES</h2>
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<h3>INPUT FILES</h3>
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On startup,
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<i>unroff
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</i>loads the Scheme source files that control the translation process.<tt> </tt>
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All these files are loaded from subdirectories of a site-specific
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``library directory'', typically something like
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<b>/usr/local/lib/unroff</b>.<tt> </tt>
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The directory is usually chosen by the system administrator when
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installing the software and can be overridden by setting the
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<b>UNROFF_DIR
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</b>environment variable.<tt> </tt>
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The path names mentioned in the following are relative to this
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library directory.<tt> </tt>
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<p>
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The first Scheme file loaded is
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<b>scm/troff.scm
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</b>which contains basic definitions such as the built-in options
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and option types, implementations for troff requests that are
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not output-format specific, and utility functions to be used
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by the back-ends or by user-supplied extensions.<tt> </tt>
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Next, the file
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<b>scm/</b><i>format</i><b>/common.scm
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</b>is loaded, where
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<i>format
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</i>is the value of the option
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<b>-f
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</b>as given on the command line (or its default value).<tt> </tt>
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The file implements the translation of the basic troff
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requests, escape sequences, and special characters, etc.<tt> </tt>
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The code dealing with macro invocations is loaded from
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<b>scm/</b><i>format</i><b>/</b><i>package</i><b>.scm
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</b>where
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<i>package
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</i>is the value of the option
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<b>-m
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</b>with the letter `m' prepended.<tt> </tt>
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<p>
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Finally, the file
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<b>.unroff
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</b>is loaded from the caller's home directory if present.<tt> </tt>
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Arbitrary Scheme code can be placed in this initialization file.<tt> </tt>
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It is typically used to assign values to package-specific
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keyword/value options according to the user's preferences
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(by means of the
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<i>set-option!
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</i>Scheme primitive as explained in the Programmer's Manual).<tt> </tt>
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<p>
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When the initial files have been loaded, any troff input files specified
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in the command line are read and parsed.<tt> </tt>
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The special file name
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`<b>-</b>'
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can be used to indicate standard input (usually in combination with
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ordinary file names).<tt> </tt>
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If no file name is given,
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<i>unroff
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</i>reads from standard input.<tt> </tt>
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<p>
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In addition to troff input files, file containing Scheme code can
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be mentioned in the command line.<tt> </tt>
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Scheme files (which by convention end in
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<b>.scm</b>)
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are loaded into the Scheme interpreter and usually contain
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used-defined Scheme procedures to translate specific macros or
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to replace existing procedures, or other user-supplied extensions
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of any kind.<tt> </tt>
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Scheme files named in the command line (or loaded explicitly from
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within other files) are resolved against the directory
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<b>scm/misc/
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</b>which may hold site-specific extensions or other supplementary
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packages.<tt> </tt>
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troff files and Scheme files can be mixed freely in the command line.<tt> </tt>
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<h3>OUTPUT FILES</h3>
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Whether
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<i>unroff
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</i>sends its output to standard output or produces one or more output
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files is not hard-wired but determined by the combination of output
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format and macro package.<tt> </tt>
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Generally, if no troff input files are specified, output is directed
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to standard output, but this rule is not mandatory and may
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be overridden by specific back-ends.<tt> </tt>
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The
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<b>document
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</b>option is usually honored, although other rules may be employed to
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determine the names of output files (for example, the extension
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that implements
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<b>-man
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</b>for a given output format may derive the name of the output file
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for a manual page from the input file name; see
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<b>unroff-html-man</b>(1)).<tt> </tt>
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<p>
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If
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<i>unroff
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</i>is interrupted or quits early, any output files produced so far may be
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incomplete or may contain wrong or inconsistent data, because
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several passes may be required to complete an output file (for example,
|
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to resolve cross references between a set of files), or because
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an output file is not necessarily produced as a whole, but
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<i>unroff
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</i>may work on several files simultaneously.<tt> </tt>
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<h2>EXAMPLES</h2>
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<p>
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To translate a troff document composed of two files and written with the
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``ms'' macro package to HTML 2.0,
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<i>unroff
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</i>might be called like this:
|
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<dl><dt><dd>
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<pre>
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unroff -fhtml -ms doc.tr doc.tr
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</pre>
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</dl>
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Two options specific to the combination of
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<b>-fhtml
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</b>and
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<b>-ms
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</b>might be added to specify a prefix for output files and to have
|
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the resulting output split into separate files after each section
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(see
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<b>unroff-html-ms</b>(1)):
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<dl><dt><dd>
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<pre>
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unroff -fhtml -ms document=out/ split=1 doc.tr doc.tr
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</pre>
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</dl>
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Additional features may be loaded from Scheme files specified in the
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command line, e.g.
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<b>hyper.scm
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</b>which implements general Hypertext requests (and gets loaded from
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<b>scm/misc/</b>)
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and a user-supplied file in the current directory providing translation
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rules for user-defined troff macros:
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<dl><dt><dd>
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<pre>
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unroff -fhtml -ms document=out/ split=1 hyper.scm doc.scm\
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doc.tr doc.tr
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</pre>
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</dl>
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<h2>TROFF SUPPORT AND EXTENSIONS</h2>
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As
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<i>unroff
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</i>translates troff input into another language rather than typesetting
|
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the text in the usual way, its processing model necessarily differs
|
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from that of conventional troff.<tt> </tt>
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For a detailed description refer to the Programmer's Manual.<tt> </tt>
|
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<p>
|
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In brief,
|
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<i>unroff
|
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</i>copies characters from input to output, optionally performing
|
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target-language-specific character translations.<tt> </tt>
|
|
For each request or macro invocation, string or number register
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reference, special character, escape sequence, sentence end, or
|
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<b>eqn</b>(1)
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inline equation encountered in the input stream,
|
|
<i>unroff
|
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</i>checks whether an ``event value'' has been specified by
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the Scheme code (user-supplied or part of the back-end).<tt> </tt>
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|
An event value is either a plain string, which is then treated as
|
|
if it had been part of the input stream, or a Scheme procedure,
|
|
which is then invoked and must in turn return a string.<tt> </tt>
|
|
The Scheme procedures are passed arguments, e.g. the macro
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or request arguments in case of a procedure attached to a macro
|
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or request, or an escape sequence argument for functions such as
|
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`\f' or `\w'.<tt> </tt>
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<p>
|
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If no event value has been associated with a particular macro,
|
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string, or number register,
|
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<i>unroff
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</i>checks whether a definition has been supplied in the normal way,
|
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i.e. by means of
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<b>.de</b>,
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<b>.ds</b>,
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or
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<b>.nr</b>.<tt> </tt>
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In this case, the value of the macro, string, or register is
|
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interpolated as done by ordinary troff.<tt> </tt>
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If no definition can be found, a fallback definition is looked up
|
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as a last resort; and if everything fails, a warning is printed
|
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and the event is ignored.<tt> </tt>
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Similarly, event procedures are invoked at end of input line,
|
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when an input file is opened or closed, at program start and
|
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termination, and for each option specified in the command line;
|
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but these procedures are called solely for their side-effects
|
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(i.e. the return values are ignored).<tt> </tt>
|
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<p>
|
|
Most Scheme procedures just emit the target language's representation
|
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of the event with which they are associated.<tt> </tt>
|
|
Other procedures perform various kinds of bookkeeping; the procedure
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associated with the
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<b>.de
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</b>request, for example, puts the text following
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aside for later expansion, and the event procedures attached to
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the requests
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<b>.ds
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</b>and
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<b>.nr
|
|
</b>and to the escape sequences `\*' and `\n'
|
|
implement troff strings and number registers.<tt> </tt>
|
|
This way, even basic troff functions need not be hard-wired and can
|
|
be altered or replaced freely without recompiling
|
|
<i>unroff</i>.<tt> </tt>
|
|
<p>
|
|
The rule that an event value associated with a macro has precedence
|
|
over the actual macro definition accommodates higher-level,
|
|
structure-oriented target languages (such as SGML).<tt> </tt>
|
|
While the micro-formatting contained in a typical
|
|
<b>-ms
|
|
</b>macro definition, for example, makes sense to an ordinary typesetting
|
|
program, it is usually impossible to infer the macro's
|
|
<i>structural
|
|
</i>function from it (new paragraph, quotation, etc.).<tt> </tt>
|
|
On the other hand, troff documents often define a few additional,
|
|
simple macros that just serve as an abbreviation for a sequence
|
|
of predefined macros; in this case event procedures need not
|
|
specified, as
|
|
<i>unroff
|
|
</i>will then perform normal macro expansion.<tt> </tt>
|
|
<p>
|
|
<i>unroff
|
|
</i>usually takes care to not rescan the characters returned by event
|
|
procedures as if their results had been normal input, because
|
|
most event procedures already return code in the target language rather
|
|
than troff input that can be rescanned.<tt> </tt>
|
|
This, however, cannot always be avoided; for example, if a troff string
|
|
reference occurs at macro definition time (because `\*' is used rather
|
|
than `\\*'), the string value ends up in the macro body and will still
|
|
be rescanned when the macro is invoked.<tt> </tt>
|
|
A few other pitfalls caused by differences in the processing models of
|
|
troff and
|
|
<i>unroff
|
|
</i>are listed in the BUGS section below.<tt> </tt>
|
|
<p>
|
|
The scaling performed for the usual troff scale indicators
|
|
can be manipulated by a calling a Scheme primitive from within
|
|
the Scheme code implementing a particular back-end.<tt> </tt>
|
|
<h3>NEW TROFF REQUESTS</h3>
|
|
To aid transparent output of code in the target language and
|
|
evaluation of inline Scheme code,
|
|
<i>unroff
|
|
</i>supports two new requests and two extensions to the
|
|
<b>.ig
|
|
</b>(ignore input lines) troff request.<tt> </tt>
|
|
<p>
|
|
If
|
|
<b>.ig
|
|
</b>is called with the symbol
|
|
<b>>>
|
|
</b>as its first argument, all input lines up to (but not including)
|
|
the terminating
|
|
<b>.>>
|
|
</b>are sent to the current output file.<tt> </tt>
|
|
Example:
|
|
when translating to the Hypertext Markup Language, the construct
|
|
could be used to emit literal HTML code like this:
|
|
<dl><dt><dd>
|
|
<pre>
|
|
.ig >>
|
|
<address>
|
|
Bart Simpson<br>
|
|
Springfield
|
|
</address>
|
|
.>>
|
|
</pre>
|
|
</dl>
|
|
<p>
|
|
To produce a single line of output, the new request
|
|
<b>.>>
|
|
</b>can be used as in this HTML example:
|
|
<dl><dt><dd>
|
|
<pre>
|
|
.>> "<code>result = i+1;</code>"
|
|
</pre>
|
|
</dl>
|
|
<p>
|
|
If the
|
|
<b>.ig
|
|
</b>request is called with the argument
|
|
<b>##,
|
|
</b>everything up to the terminating
|
|
<b>.##
|
|
</b>is passed to the Scheme interpreter for evaluation.<tt> </tt>
|
|
This allows users to embed Scheme code in a troff document which
|
|
is executed when the document is processed by
|
|
<i>unroff</i>.<tt> </tt>
|
|
One use of this construct is to provide a Scheme event procedure
|
|
for a user-defined macro by placing the corresponding Scheme
|
|
definition in the same source file right below the troff macro definition.<tt> </tt>
|
|
Similarly, the request
|
|
<b>.##
|
|
</b>can be used to evaluate a short S-expression; all arguments to
|
|
the request are concatenated and then passed to the Scheme
|
|
interpreter.<tt> </tt>
|
|
<p>
|
|
Note that inline Scheme code is a potentially dangerous feature,
|
|
as a document received by someone else may contain embedded code
|
|
that does something unexpected when the file is processed by
|
|
<i>unroff
|
|
</i>(but it is probably not more dangerous than the standard troff
|
|
<b>.pi
|
|
</b>request or the
|
|
<b>.sy
|
|
</b>request of
|
|
<i>ditroff</i>).<tt> </tt>
|
|
<p>
|
|
<i>unroff
|
|
</i>defines the following new read-only number registers:
|
|
<dl>
|
|
<dt><b>.U
|
|
</b><dd>
|
|
This register always expand to 1.<tt> </tt>
|
|
It can be used by macros to determine whether the document is
|
|
being processed by
|
|
<i>unroff</i>.<tt> </tt>
|
|
<dt><b>.C
|
|
</b><dd>
|
|
Expands to 1 if troff compatibility mode has been enabled
|
|
by using the option
|
|
<b>-C</b>,
|
|
to 0 otherwise.<tt> </tt>
|
|
</dl>
|
|
<p>
|
|
The following new escape sequences are available in a macro
|
|
body during macro expansion:
|
|
<dl>
|
|
<dt><b>$0
|
|
</b><dd>
|
|
The name of the current macro.<tt> </tt>
|
|
<dt><b>$*
|
|
</b><dd>
|
|
The concatenation of all arguments, separated by spaces.<tt> </tt>
|
|
<dt><b>$@
|
|
</b><dd>
|
|
The concatenation of all arguments, separated by spaces, and
|
|
with each argument enclosed by double quotes.<tt> </tt>
|
|
</dl>
|
|
<p>
|
|
The names of strings, macros, number registers, and fonts may be of
|
|
any length.<tt> </tt>
|
|
As in
|
|
<i>groff</i>,
|
|
square brackets can be used for names of arbitrary length:
|
|
<dl><dt><dd>
|
|
<pre>
|
|
\f[font] \*[string] \n[numreg] ...
|
|
</pre>
|
|
</dl>
|
|
<p>
|
|
There is no limit on the number of macro arguments, and the following
|
|
syntax can be used to reference the 10th, 11th, etc. macro argument:
|
|
<dl><dt><dd>
|
|
<pre>
|
|
\$(12 \$[12] \$[123]
|
|
</pre>
|
|
</dl>
|
|
<p>
|
|
Unless troff compatibility mode has been enabled, the arguments to the
|
|
<i>groff</i>-specific
|
|
escape sequences `\A', `\C', '\L', '\N', '\R', '\V', '\Y',
|
|
and '\Z' are recognized and parsed, so that event procedures
|
|
can be implemented correctly for these escape sequences.<tt> </tt>
|
|
<h2>SEE ALSO</h2>
|
|
<b>unroff-html</b>(1),
|
|
<b>unroff-html-man</b>(1),
|
|
<b>unroff-html-ms</b>(1);
|
|
<br>
|
|
<b>troff</b>(1),
|
|
<b>groff</b>(1);
|
|
<b>elk</b>(1).<tt> </tt>
|
|
<p>
|
|
Unroff Programmer's Manual.<tt> </tt>
|
|
<p>
|
|
http://www.informatik.uni-bremen.de/~net/unroff
|
|
<h2>AUTHOR</h2>
|
|
Oliver Laumann, net@cs.tu-berlin.de
|
|
<h2>BUGS</h2>
|
|
A number of low-level formatting features of troff (such as the
|
|
absolute position indicator in numerical expressions)
|
|
are not yet supported by
|
|
<i>unroff
|
|
</i>version 1.0, which is not critical for higher-level,
|
|
structure-oriented target languages such as the Hypertext
|
|
Markup Language.<tt> </tt>
|
|
<p>
|
|
Diversions are not supported, although specific back-ends are
|
|
free to add this functionality.<tt> </tt>
|
|
<p>
|
|
Special characters are not treated right in certain contexts;
|
|
in particular, special characters may not be used in place
|
|
of plain characters where the characters act as some kind of
|
|
delimiter as in
|
|
<dl><dt><dd>
|
|
<pre>
|
|
.if \(bsfoo\(bsbar\(bs ...
|
|
</pre>
|
|
</dl>
|
|
<p>
|
|
Spaces in an
|
|
<b>.if
|
|
</b>condition do not work; e.g. the following fails:
|
|
<dl><dt><dd>
|
|
<pre>
|
|
.if ' ' ' ...
|
|
</pre>
|
|
</dl>
|
|
<p>
|
|
Conditional input is subject to string and number register
|
|
expansion even if the corresponding if-condition evaluates to false.<tt> </tt>
|
|
<p>
|
|
There are no number register formats, i.e. the request
|
|
<b>.af
|
|
</b>does not work.<tt> </tt>
|
|
<p>
|
|
The set of punctuation marks that indicate end of sentence
|
|
should be configurable.<tt> </tt>
|
|
<p>
|
|
Empty input lines and leading space should trigger a special
|
|
event, so that their break semantics can be implemented correctly.<tt> </tt>
|
|
<p>
|
|
A comment in a line by itself currently does not generate a
|
|
blank line.<tt> </tt>
|
|
<p><hr>
|
|
Markup created by <em>unroff</em> 1.0, <tt> </tt> <tt> </tt>March 21, 1996.
|
|
</body>
|
|
</html>
|