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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:44:05 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:44:05 +0000 |
| commit | d318611dd6f23fcfedd50e9b9e24620b102ba96a (patch) | |
| tree | 8b9eef82ca40fdd5a8deeabf07572074c236095d /doc/groff.html.node/groff.html_fot.html | |
| parent | Initial commit. (diff) | |
| download | groff-upstream.tar.xz groff-upstream.zip | |
Adding upstream version 1.23.0.upstream/1.23.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'doc/groff.html.node/groff.html_fot.html')
| -rw-r--r-- | doc/groff.html.node/groff.html_fot.html | 525 |
1 files changed, 525 insertions, 0 deletions
diff --git a/doc/groff.html.node/groff.html_fot.html b/doc/groff.html.node/groff.html_fot.html new file mode 100644 index 0000000..1230044 --- /dev/null +++ b/doc/groff.html.node/groff.html_fot.html @@ -0,0 +1,525 @@ +<!DOCTYPE html> +<html> +<!-- Created by GNU Texinfo 7.0.3, https://www.gnu.org/software/texinfo/ --> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> +<!-- This manual documents GNU troff version 1.23.0. + +Copyright © 1994-2023 Free Software Foundation, Inc. + +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.3 or +any later version published by the Free Software Foundation; with no +Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A +copy of the license is included in the section entitled "GNU Free +Documentation License". --> +<title>Footnotes (The GNU Troff Manual)</title> + +<meta name="description" content="Footnotes (The GNU Troff Manual)"> +<meta name="keywords" content="Footnotes (The GNU Troff Manual)"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="makeinfo"> +<meta name="viewport" content="width=device-width,initial-scale=1"> + +<link href="index.html" rel="start" title="Top"> +<link href="Request-Index.html" rel="index" title="Request Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<style type="text/css"> +<!-- +kbd.key {font-style: normal} +span.r {font-family: initial; font-weight: normal; font-style: normal} +--> +</style> + + +</head> + +<body lang="en"> +<div class="element-footnotes" id="SEC_Footnotes"> +<div class="nav-panel"> +<p> + [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Request-Index.html" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<h4 class="footnotes-heading">Footnotes</h4> + +<h5 class="footnote-body-heading"><a id="FOOT1" href="Preprocessor-Intro.html#DOCF1">(1)</a></h5> +<p>The ‘<samp class="samp">g</samp>’ prefix is +not used on all systems; see <a class="ref" href="Invoking-groff.html">Invoking <code class="code">groff</code></a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT2" href="Conventions-Used-in-This-Manual.html#DOCF2">(2)</a></h5> +<p>Unix and related operating systems distinguish +standard output and standard error streams <em class="emph">because</em> of +<code class="code">troff</code>: +<a class="uref" href="https://minnie.tuhs.org/pipermail/tuhs/2013-December/006113.html">https://minnie.tuhs.org/pipermail/tuhs/2013-December/006113.html</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT3" href="Conventions-Used-in-This-Manual.html#DOCF3">(3)</a></h5> +<p>See <a class="xref" href="Line-Layout.html">Line Layout</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT4" href="Invoking-groff.html#DOCF4">(4)</a></h5> +<p>Besides <code class="code">groff</code>, <code class="code">neatroff</code> is an +exception.</p> +<h5 class="footnote-body-heading"><a id="FOOT5" href="Macro-Directories.html#DOCF5">(5)</a></h5> +<p>The +<code class="code">mso</code> request does not have these limitations. See <a class="xref" href="I_002fO.html">I/O</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT6" href="Basics.html#DOCF6">(6)</a></h5> +<p>The remainder of this chapter is based on +<cite class="cite">Writing Papers with nroff using -me</cite> by Eric P. Allman, +which is distributed with <code class="code">groff</code> as <samp class="file">meintro.me</samp>.</p> +<h5 class="footnote-body-heading"><a id="FOOT7" href="ms-Introduction.html#DOCF7">(7)</a></h5> +<p>While manual <em class="emph">pages</em> are older, early ones used +macros supplanted by the <samp class="file">man</samp> package of Seventh Edition Unix +(1979). <samp class="file">ms</samp> shipped with Sixth Edition (1975) and was documented +by Mike Lesk in a Bell Labs internal memorandum.</p> +<h5 class="footnote-body-heading"><a id="FOOT8" href="ms-Document-Control-Settings.html#DOCF8">(8)</a></h5> +<p>defined in <a class="ref" href="ms-Footnotes.html">Footnotes</a></p> +<h5 class="footnote-body-heading"><a id="FOOT9" href="ms-Document-Description-Macros.html#DOCF9">(9)</a></h5> +<p>Distinguish a +document title from “titles”, which are what <code class="code">roff</code> systems call +headers and footers collectively.</p> +<h5 class="footnote-body-heading"><a id="FOOT10" href="Typeface-and-decoration.html#DOCF10">(10)</a></h5> +<p>This idiosyncrasy arose through +feature accretion; for example, the <code class="code">B</code> macro in Version 6 +Unix <samp class="file">ms</samp> (1975) accepted only one argument, the text to be set in +boldface. By Version 7 (1979) it recognized a second argument; in +1990, <code class="code">groff</code> <samp class="file">ms</samp> added a “pre” argument, placing it third +to avoid breaking support for older documents.</p> +<h5 class="footnote-body-heading"><a id="FOOT11" href="ms-Footnotes.html#DOCF11">(11)</a></h5> +<p>“Portable Document Format Publishing with GNU +Troff”, <samp class="file">pdfmark.ms</samp> in the <code class="code">groff</code> distribution, uses this +technique.</p> +<h5 class="footnote-body-heading"><a id="FOOT12" href="ms-Footnotes.html#DOCF12">(12)</a></h5> +<p>Unix Version 7 <samp class="file">ms</samp>, its descendants, and GNU +<samp class="file">ms</samp> prior to <code class="code">groff</code> version 1.23.0</p> +<h5 class="footnote-body-heading"><a id="FOOT13" href="ms-Footnotes.html#DOCF13">(13)</a></h5> +<p>You could reset it +after each call to <code class="code">.1C</code>, <code class="code">.2C</code>, or <code class="code">.MC</code>.</p> +<h5 class="footnote-body-heading"><a id="FOOT14" href="Differences-from-AT_0026T-ms.html#DOCF14">(14)</a></h5> +<p><cite class="cite">Typing Documents on the UNIX System: Using the +-ms Macros with Troff and Nroff</cite>, M. E. Lesk, Bell Laboratories, +1978</p> +<h5 class="footnote-body-heading"><a id="FOOT15" href="Differences-from-AT_0026T-ms.html#DOCF15">(15)</a></h5> +<p>Register values are converted to and stored as +basic units. See <a class="xref" href="Measurements.html">Measurements</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT16" href="Differences-from-AT_0026T-ms.html#DOCF16">(16)</a></h5> +<p>If you redefine the <samp class="file">ms</samp> <code class="code">PT</code> macro +and desire special treatment of certain page numbers (like ‘<samp class="samp">1</samp>’), +you may need to handle a non-Arabic page number format, as <code class="code">groff</code> +<samp class="file">ms</samp>’s <code class="code">PT</code> does; see the macro package source. <code class="code">groff</code> +<samp class="file">ms</samp> aliases the <code class="code">PN</code> register to <code class="code">%</code>.</p> +<h5 class="footnote-body-heading"><a id="FOOT17" href="Missing-Unix-Version-7-ms-Macros.html#DOCF17">(17)</a></h5> +<p>The removal beforehand is necessary +because <code class="code">groff</code> <samp class="file">ms</samp> aliases these macros to a diagnostic +macro, and you want to redefine the aliased name, not its target.</p> +<h5 class="footnote-body-heading"><a id="FOOT18" href="Filling.html#DOCF18">(18)</a></h5> +<p>See <a class="xref" href="Device-and-Font-Description-Files.html">Device and Font Description Files</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT19" href="Filling.html#DOCF19">(19)</a></h5> +<p><i class="slanted">Tabs</i> and <i class="slanted">leaders</i> also separate +words. <i class="slanted">Escape sequences</i> can function as word characters, word +separators, or neither—the last simply have no effect on GNU +<code class="code">troff</code>’s idea of whether an input character is within a word. +We’ll discuss all of these in due course.</p> +<h5 class="footnote-body-heading"><a id="FOOT20" href="Sentences.html#DOCF20">(20)</a></h5> +<p>A +well-researched jeremiad appreciated by <code class="code">groff</code> contributors on +both sides of the sentence-spacing debate can be found at +<a class="uref" href="https://web.archive.org/web/20171217060354/http://www.heracliteanriver.com/?p=324">https://web.archive.org/web/20171217060354/http://www.heracliteanriver.com/?p=324</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT21" href="Sentences.html#DOCF21">(21)</a></h5> +<p>This statement oversimplifies; there are +escape sequences whose purpose is precisely to produce glyphs on the +output device, and input characters that <em class="emph">aren’t</em> part of escape +sequences can undergo a great deal of processing before getting to the +output.</p> +<h5 class="footnote-body-heading"><a id="FOOT22" href="Sentences.html#DOCF22">(22)</a></h5> +<p>The mnemonics for the special +characters shown here are “dagger”, “double dagger”, “right +(double) quote”, and “closing (single) quote”. See the +<cite class="cite">groff_char<span class="r">(7)</span></cite> man page.</p> +<h5 class="footnote-body-heading"><a id="FOOT23" href="Breaking.html#DOCF23">(23)</a></h5> +<p>“Text lines” are defined in <a class="ref" href="Requests-and-Macros.html">Requests and Macros</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT24" href="Tabs-and-Leaders.html#DOCF24">(24)</a></h5> +<p>“Tab” +is short for “tabulation”, revealing the term’s origin as a spacing +mechanism for table arrangement.</p> +<h5 class="footnote-body-heading"><a id="FOOT25" href="Requests-and-Macros.html#DOCF25">(25)</a></h5> +<p>The <code class="code">\<kbd class="key">RET</kbd></code> escape sequence can alter how an +input line is classified; see <a class="ref" href="Line-Continuation.html">Line Continuation</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT26" href="Requests-and-Macros.html#DOCF26">(26)</a></h5> +<p>Argument handling in +macros is more flexible but also more complex. See <a class="xref" href="Calling-Macros.html">Calling Macros</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT27" href="Requests-and-Macros.html#DOCF27">(27)</a></h5> +<p>Some escape sequences undergo +interpolation as well.</p> +<h5 class="footnote-body-heading"><a id="FOOT28" href="Requests-and-Macros.html#DOCF28">(28)</a></h5> +<p>GNU <code class="code">troff</code> offers additional ones. See <a class="xref" href="Writing-Macros.html">Writing Macros</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT29" href="Macro-Packages.html#DOCF29">(29)</a></h5> +<p>Macro files and packages +frequently define registers and strings as well.</p> +<h5 class="footnote-body-heading"><a id="FOOT30" href="Input-Encodings.html#DOCF30">(30)</a></h5> +<p>The +<em class="emph">semantics</em> of certain punctuation code points have gotten stricter +with the successive standards, a cause of some frustration among man +page writers; see the <cite class="cite">groff_char<span class="r">(7)</span></cite> man page.</p> +<h5 class="footnote-body-heading"><a id="FOOT31" href="Input-Encodings.html#DOCF31">(31)</a></h5> +<p>The +DVI output device defaults to using the Computer Modern (CM) fonts; +<samp class="file">ec.tmac</samp> loads the EC fonts instead, which provide Euro +‘<samp class="samp">\[Eu]</samp>’ and per mille ‘<samp class="samp">\[%0]</samp>’ glyphs.</p> +<h5 class="footnote-body-heading"><a id="FOOT32" href="Input-Conventions.html#DOCF32">(32)</a></h5> +<p>Emacs: <code class="code">fill-column: 72</code>; Vim: <code class="code">textwidth=72</code></p> +<h5 class="footnote-body-heading"><a id="FOOT33" href="Page-Geometry.html#DOCF33">(33)</a></h5> +<p><code class="code">groff</code> does not yet support right-to-left +scripts.</p> +<h5 class="footnote-body-heading"><a id="FOOT34" href="Page-Geometry.html#DOCF34">(34)</a></h5> +<p><code class="code">groff</code>’s terminal output devices have page +offsets of zero.</p> +<h5 class="footnote-body-heading"><a id="FOOT35" href="Numeric-Expressions.html#DOCF35">(35)</a></h5> +<p>Provision is made for interpreting and +reporting decimal fractions in certain cases.</p> +<h5 class="footnote-body-heading"><a id="FOOT36" href="Numeric-Expressions.html#DOCF36">(36)</a></h5> +<p>If that’s not enough, see the <cite class="cite">groff_tmac<span class="r">(5)</span></cite> +man page for the <samp class="file">62bit.tmac</samp> macro package.</p> +<h5 class="footnote-body-heading"><a id="FOOT37" href="Numeric-Expressions.html#DOCF37">(37)</a></h5> +<p>See <a class="xref" href="Conditionals-and-Loops.html">Conditionals and Loops</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT38" href="Numeric-Expressions.html#DOCF38">(38)</a></h5> +<p>Control structure syntax +creates an exception to this rule, but is designed to remain useful: +recalling our example, ‘<samp class="samp">.if 1 .Underline this</samp>’ would underline only +“this”, precisely. See <a class="xref" href="Conditionals-and-Loops.html">Conditionals and Loops</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT39" href="Numeric-Expressions.html#DOCF39">(39)</a></h5> +<p>See <a class="xref" href="Diversions.html">Diversions</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT40" href="Identifiers.html#DOCF40">(40)</a></h5> +<p>Historically, control characters like +ASCII STX, ETX, and BEL (<kbd class="key">Control+B</kbd>, <kbd class="key">Control+C</kbd>, and +<kbd class="key">Control+G</kbd>) have been observed in <code class="code">roff</code> documents, +particularly in macro packages employing them as delimiters with the +output comparison operator to try to avoid collisions with the content +of arbitrary user-supplied parameters (see <a class="pxref" href="Operators-in-Conditionals.html">Operators in Conditionals</a>). We discourage this expedient; in GNU <code class="code">troff</code> it is +unnecessary (outside of compatibility mode) because delimited arguments +are parsed at a different input level than the surrounding context. +See <a class="xref" href="Implementation-Differences.html">Implementation Differences</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT41" href="Identifiers.html#DOCF41">(41)</a></h5> +<p>Consider what happens when a C1 control +<code class="code">0x80</code>–<code class="code">0x9F</code> is necessary as a continuation byte in a UTF-8 +sequence.</p> +<h5 class="footnote-body-heading"><a id="FOOT42" href="Control-Characters.html#DOCF42">(42)</a></h5> +<p>Recall <a class="ref" href="Identifiers.html">Identifiers</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT43" href="Invoking-Requests.html#DOCF43">(43)</a></h5> +<p>In compatibility +mode, a space is not necessary after a request or macro name of two +characters’ length. Also, Plan 9 <code class="code">troff</code> allows tabs to +separate arguments.</p> +<h5 class="footnote-body-heading"><a id="FOOT44" href="Calling-Macros.html#DOCF44">(44)</a></h5> +<p><code class="code">\~</code> is fairly +portable; see <a class="ref" href="Other-Differences.html">Other Differences</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT45" href="Calling-Macros.html#DOCF45">(45)</a></h5> +<p>Strictly, you can neglect to +close the last quoted macro argument, relying on the end of the control +line to do so. We consider this lethargic practice poor style.</p> +<h5 class="footnote-body-heading"><a id="FOOT46" href="Using-Escape-Sequences.html#DOCF46">(46)</a></h5> +<p>The omission of spaces before the comment +escape sequences is necessary; see <a class="ref" href="Strings.html">Strings</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT47" href="Using-Escape-Sequences.html#DOCF47">(47)</a></h5> +<p>TeX does have such a mechanism.</p> +<h5 class="footnote-body-heading"><a id="FOOT48" href="Comments.html#DOCF48">(48)</a></h5> +<p>This claim may be more aspirational than descriptive.</p> +<h5 class="footnote-body-heading"><a id="FOOT49" href="Comments.html#DOCF49">(49)</a></h5> +<p>See <a class="xref" href="Conditional-Blocks.html">Conditional Blocks</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT50" href="Comments.html#DOCF50">(50)</a></h5> +<p>Exception: auto-incrementing registers defined outside +the ignored region <em class="emph">will</em> be modified if interpolated with +<code class="code">\n±</code> inside it. See <a class="xref" href="Auto_002dincrement.html">Auto-increment</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT51" href="Auto_002dincrement.html#DOCF51">(51)</a></h5> +<p>A negative auto-increment can be +considered an “auto-decrement”.</p> +<h5 class="footnote-body-heading"><a id="FOOT52" href="Built_002din-Registers.html#DOCF52">(52)</a></h5> +<p>GNU <code class="code">troff</code> dynamically allocates memory for +as many registers as required.</p> +<h5 class="footnote-body-heading"><a id="FOOT53" href="Manipulating-Filling-and-Adjustment.html#DOCF53">(53)</a></h5> +<p>unless diverted; see <a class="ref" href="Diversions.html">Diversions</a></p> +<h5 class="footnote-body-heading"><a id="FOOT54" href="Manipulating-Filling-and-Adjustment.html#DOCF54">(54)</a></h5> +<p>See <a class="xref" href="Line-Continuation.html">Line Continuation</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT55" href="Manipulating-Filling-and-Adjustment.html#DOCF55">(55)</a></h5> +<p>Recall <a class="ref" href="Filling.html">Filling</a> and <a class="ref" href="Sentences.html">Sentences</a> for the +definitions of word and sentence boundaries, respectively.</p> +<h5 class="footnote-body-heading"><a id="FOOT56" href="Manipulating-Hyphenation.html#DOCF56">(56)</a></h5> +<p>Whether a perfect algorithm for this application is +even possible is an unsolved problem in computer science: +<a class="url" href="https://tug.org/docs/liang/liang-thesis.pdf">https://tug.org/docs/liang/liang-thesis.pdf</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT57" href="Manipulating-Hyphenation.html#DOCF57">(57)</a></h5> +<p><code class="code">\%</code> itself stops marking +hyphenation points but still produces no output glyph.</p> +<h5 class="footnote-body-heading"><a id="FOOT58" href="Manipulating-Hyphenation.html#DOCF58">(58)</a></h5> +<p>“Soft” because it appears in output +only where a hyphenation break is performed; a “hard” hyphen, as in +“long-term”, always appears.</p> +<h5 class="footnote-body-heading"><a id="FOOT59" href="Manipulating-Hyphenation.html#DOCF59">(59)</a></h5> +<p>The mode is a vector of Booleans encoded as an integer. +To a programmer, this fact is easily deduced from the exclusive use of +powers of two for the configuration parameters; they are computationally +easy to “mask off” and compare to zero. To almost everyone else, the +arrangement seems recondite and unfriendly.</p> +<h5 class="footnote-body-heading"><a id="FOOT60" href="Manipulating-Hyphenation.html#DOCF60">(60)</a></h5> +<p>Hyphenation is +prevented if the next page location trap is closer to the vertical +drawing position than the next text baseline would be. See <a class="xref" href="Page-Location-Traps.html">Page Location Traps</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT61" href="Manipulating-Hyphenation.html#DOCF61">(61)</a></h5> +<p>For more on localization, see the +<cite class="cite">groff_tmac<span class="r">(5)</span></cite> man page.</p> +<h5 class="footnote-body-heading"><a id="FOOT62" href="Manipulating-Spacing.html#DOCF62">(62)</a></h5> +<p>See <a class="xref" href="Page-Location-Traps.html">Page Location Traps</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT63" href="Manipulating-Spacing.html#DOCF63">(63)</a></h5> +<p>See <a class="xref" href="Drawing-Geometric-Objects.html">Drawing Geometric Objects</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT64" href="Manipulating-Spacing.html#DOCF64">(64)</a></h5> +<p>or geometric objects; see <a class="ref" href="Drawing-Geometric-Objects.html">Drawing Geometric Objects</a></p> +<h5 class="footnote-body-heading"><a id="FOOT65" href="Manipulating-Spacing.html#DOCF65">(65)</a></h5> +<p>to the top-level diversion; +see <a class="ref" href="Diversions.html">Diversions</a></p> +<h5 class="footnote-body-heading"><a id="FOOT66" href="Tabs-and-Fields.html#DOCF66">(66)</a></h5> +<p>Plan 9 <code class="code">troff</code> +uses the register <code class="code">.S</code> for this purpose.</p> +<h5 class="footnote-body-heading"><a id="FOOT67" href="Leaders.html#DOCF67">(67)</a></h5> +<p>This is pronounced to rhyme with “feeder”, and +refers to how the glyphs “lead” the eye across the page to the +corresponding page number or other datum.</p> +<h5 class="footnote-body-heading"><a id="FOOT68" href="troff-and-nroff-Modes.html#DOCF68">(68)</a></h5> +<p>A +GNU <code class="command">nroff</code> program is available for convenience; it calls GNU +<code class="code">troff</code> to perform the formatting.</p> +<h5 class="footnote-body-heading"><a id="FOOT69" href="Line-Continuation.html#DOCF69">(69)</a></h5> +<p>Historically, the <code class="code">\c</code> +escape sequence has proven challenging to characterize. Some sources +say it “connects the next input text” (to the input line on which it +appears); others describe it as “interrupting” text, on the grounds +that a text line is interrupted without breaking, perhaps to inject a +request invocation or macro call.</p> +<h5 class="footnote-body-heading"><a id="FOOT70" href="Page-Layout.html#DOCF70">(70)</a></h5> +<p>See <a class="xref" href="Traps.html">Traps</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT71" href="Page-Control.html#DOCF71">(71)</a></h5> +<p>See <a class="xref" href="Diversions.html">Diversions</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT72" href="Using-Fonts.html#DOCF72">(72)</a></h5> +<p>Terminals and some output devices have fonts that render +at only one or two sizes. As examples of the latter, take the +<code class="code">groff</code> <code class="code">lj4</code> device’s Lineprinter, and <code class="code">lbp</code>’s Courier +and Elite faces.</p> +<h5 class="footnote-body-heading"><a id="FOOT73" href="Using-Fonts.html#DOCF73">(73)</a></h5> +<p>Font designers prepare families such that the styles +share esthetic properties.</p> +<h5 class="footnote-body-heading"><a id="FOOT74" href="Using-Fonts.html#DOCF74">(74)</a></h5> +<p>Historically, the fonts +<code class="code">troff</code>s dealt with were not Free Software or, as with the Graphic +Systems C/A/T, did not even exist in the digital domain.</p> +<h5 class="footnote-body-heading"><a id="FOOT75" href="Using-Fonts.html#DOCF75">(75)</a></h5> +<p>See <a class="xref" href="Font-Description-File-Format.html">Font Description File Format</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT76" href="Font-Families.html#DOCF76">(76)</a></h5> +<p>See <a class="xref" href="DESC-File-Format.html"><samp class="file">DESC</samp> File Format</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT77" href="Using-Symbols.html#DOCF77">(77)</a></h5> +<p>Not all versions of the <code class="code">man</code> program +support the <samp class="option">-T</samp> option; use the subsequent example for an +alternative.</p> +<h5 class="footnote-body-heading"><a id="FOOT78" href="Using-Symbols.html#DOCF78">(78)</a></h5> +<p>This is “Normalization Form D” +as documented in Unicode Standard Annex #15 +(<a class="uref" href="https://unicode.org/reports/tr15/">https://unicode.org/reports/tr15/</a>).</p> +<h5 class="footnote-body-heading"><a id="FOOT79" href="Using-Symbols.html#DOCF79">(79)</a></h5> +<p>See <a class="xref" href="Compatibility-Mode.html">Compatibility Mode</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT80" href="Using-Symbols.html#DOCF80">(80)</a></h5> +<p>Output glyphs +don’t—to GNU <code class="code">troff</code>, a glyph is simply a box with an index into +a font, a given height above and depth below the baseline, and a width.</p> +<h5 class="footnote-body-heading"><a id="FOOT81" href="Dummy-Characters.html#DOCF81">(81)</a></h5> +<p>Opinions of this escape sequence’s name abound. +“Zero-width space” is a popular misnomer: <code class="code">roff</code> formatters do +not treat it like a space. Ossanna called it a “non-printing, +zero-width character”, but the character causes <em class="emph">output</em> even +though it does not “print”. If no output line is pending, the dummy +character starts one. Contrast an empty input document with one +containing only <code class="code">\&</code>. The former produces no output; the latter, a +blank page.</p> +<h5 class="footnote-body-heading"><a id="FOOT82" href="Manipulating-Type-Size-and-Vertical-Spacing.html#DOCF82">(82)</a></h5> +<p>In text fonts, the tallest glyphs are typically +parentheses. Unfortunately, in many cases the actual dimensions of the +glyphs in a font do not closely match its declared type size! For +example, in the standard PostScript font families, 10-point Times sets +better with 9-point Helvetica and 11-point Courier than if all three +were used at 10 points.</p> +<h5 class="footnote-body-heading"><a id="FOOT83" href="Manipulating-Type-Size-and-Vertical-Spacing.html#DOCF83">(83)</a></h5> +<p>Rhyme with “sledding”; mechanical typography +used lead metal (Latin <em class="emph">plumbum</em>).</p> +<h5 class="footnote-body-heading"><a id="FOOT84" href="Changing-the-Type-Size.html#DOCF84">(84)</a></h5> +<p>The claim appears to have been true of Ossanna +<code class="code">troff</code> for the C/A/T device; Kernighan made device-independent +<code class="code">troff</code> more flexible.</p> +<h5 class="footnote-body-heading"><a id="FOOT85" href="Using-Fractional-Type-Sizes.html#DOCF85">(85)</a></h5> +<p>See <a class="xref" href="Device-and-Font-Description-Files.html">Device and Font Description Files</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT86" href="Colors.html#DOCF86">(86)</a></h5> +<p>also +known vulgarly as “ANSI colors”</p> +<h5 class="footnote-body-heading"><a id="FOOT87" href="Strings.html#DOCF87">(87)</a></h5> +<p>See <a class="xref" href="Copy-Mode.html">Copy Mode</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT88" href="Operators-in-Conditionals.html#DOCF88">(88)</a></h5> +<p>This refers to +<code class="code">vtroff</code>, a translator that would convert the C/A/T output from +early-vintage <abbr class="acronym">AT&T</abbr> <code class="code">troff</code> to a form suitable for +Versatec and Benson-Varian plotters.</p> +<h5 class="footnote-body-heading"><a id="FOOT89" href="Operators-in-Conditionals.html#DOCF89">(89)</a></h5> +<p>Strictly, letters not otherwise recognized <em class="emph">are</em> treated +as output comparison delimiters. For portability, it is wise to avoid +using letters not in the list above; for example, Plan 9 +<code class="code">troff</code> uses ‘<samp class="samp">h</samp>’ to test a mode it calls <code class="code">htmlroff</code>, and +GNU <code class="code">troff</code> may provide additional operators in the future.</p> +<h5 class="footnote-body-heading"><a id="FOOT90" href="Operators-in-Conditionals.html#DOCF90">(90)</a></h5> +<p>Because formatting of the comparands takes place +in a dummy environment, vertical motions within them cannot spring +traps.</p> +<h5 class="footnote-body-heading"><a id="FOOT91" href="Operators-in-Conditionals.html#DOCF91">(91)</a></h5> +<p>All +of this is to say that the lists of output nodes created by formatting +<var class="var">xxx</var> and <var class="var">yyy</var> must be identical. See <a class="xref" href="Gtroff-Internals.html"><code class="code">gtroff</code> Internals</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT92" href="Operators-in-Conditionals.html#DOCF92">(92)</a></h5> +<p>This bizarre behavior maintains compatibility with +<abbr class="acronym">AT&T</abbr> <code class="code">troff</code>.</p> +<h5 class="footnote-body-heading"><a id="FOOT93" href="Conditional-Blocks.html#DOCF93">(93)</a></h5> +<p>See <a class="xref" href="while.html">while</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT94" href="while.html#DOCF94">(94)</a></h5> +<p>See <a class="xref" href="Copy-Mode.html">Copy Mode</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT95" href="while.html#DOCF95">(95)</a></h5> +<p>unless you redefine it</p> +<h5 class="footnote-body-heading"><a id="FOOT96" href="while.html#DOCF96">(96)</a></h5> +<p>“somewhat less” because +things other than macro calls can be on the input stack</p> +<h5 class="footnote-body-heading"><a id="FOOT97" href="Writing-Macros.html#DOCF97">(97)</a></h5> +<p>See <a class="xref" href="Copy-Mode.html">Copy Mode</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT98" href="Writing-Macros.html#DOCF98">(98)</a></h5> +<p>While it is possible to define and +call a macro ‘<samp class="samp">.</samp>’, you can’t use it as an end macro: during a macro +definition, ‘<samp class="samp">..</samp>’ is never handled as calling ‘<samp class="samp">.</samp>’, even if +‘<samp class="samp">.de <var class="var">name</var> .</samp>’ explicitly precedes it.</p> +<h5 class="footnote-body-heading"><a id="FOOT99" href="Writing-Macros.html#DOCF99">(99)</a></h5> +<p>Its structure is +adapted from, and isomorphic to, part of a solution by Tadziu Hoffman to +the problem of reflowing text multiple times to find an optimal +configuration for it. +<a class="uref" href="https://lists.gnu.org/archive/html/groff/2008-12/msg00006.html">https://lists.gnu.org/archive/html/groff/2008-12/msg00006.html</a></p> +<h5 class="footnote-body-heading"><a id="FOOT100" href="Parameters.html#DOCF100">(100)</a></h5> +<p>If they were not, +parameter interpolations would be similar to command-line +parameters—fixed for the entire duration of a <code class="code">roff</code> program’s +run. The advantage of interpolating <code class="code">\$</code> escape sequences even in +copy mode is that they can interpolate different contents from one call +to the next, like function parameters in a procedural language. The +additional escape character is the price of this power.</p> +<h5 class="footnote-body-heading"><a id="FOOT101" href="Copy-Mode.html#DOCF101">(101)</a></h5> +<p>Compare this to the <code class="code">\def</code> and <code class="code">\edef</code> +commands in TeX.</p> +<h5 class="footnote-body-heading"><a id="FOOT102" href="Copy-Mode.html#DOCF102">(102)</a></h5> +<p>These are lightly adapted from the <code class="code">groff</code> +implementation of the <samp class="file">ms</samp> macros.</p> +<h5 class="footnote-body-heading"><a id="FOOT103" href="Page-Motions.html#DOCF103">(103)</a></h5> +<p>At the +<code class="code">grops</code> defaults of 10-point type on 12-point vertical spacing, the +difference between half a vee and half an em can be subtle: large +spacings like ‘<samp class="samp">.vs .5i</samp>’ make it obvious.</p> +<h5 class="footnote-body-heading"><a id="FOOT104" href="Page-Motions.html#DOCF104">(104)</a></h5> +<p>See <a class="xref" href="Strings.html">Strings</a>, for an explanation of the trailing +‘<samp class="samp">\"</samp>’.</p> +<h5 class="footnote-body-heading"><a id="FOOT105" href="Drawing-Geometric-Objects.html#DOCF105">(105)</a></h5> +<p>(<var class="var">hc</var>, <var class="var">vc</var>) is adjusted to the point nearest +the perpendicular bisector of the arc’s chord.</p> +<h5 class="footnote-body-heading"><a id="FOOT106" href="Page-Location-Traps.html#DOCF106">(106)</a></h5> +<p>See <a class="xref" href="The-Implicit-Page-Trap.html">The Implicit Page Trap</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT107" href="Page-Location-Traps.html#DOCF107">(107)</a></h5> +<p>A trap planted at ‘<samp class="samp">20i</samp>’ or +‘<samp class="samp">-30i</samp>’ will not be sprung on a page of length ‘<samp class="samp">11i</samp>’.</p> +<h5 class="footnote-body-heading"><a id="FOOT108" href="Page-Location-Traps.html#DOCF108">(108)</a></h5> +<p>It may help to think of each trap location as +maintaining a queue; <code class="code">wh</code> operates on the head of the queue, and +<code class="code">ch</code> operates on its tail. Only the trap at the head of the queue +is visible.</p> +<h5 class="footnote-body-heading"><a id="FOOT109" href="The-Implicit-Page-Trap.html#DOCF109">(109)</a></h5> +<p>See <a class="xref" href="Debugging.html">Debugging</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT110" href="The-Implicit-Page-Trap.html#DOCF110">(110)</a></h5> +<p>See <a class="xref" href="Diversions.html">Diversions</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT111" href="End_002dof_002dinput-Traps.html#DOCF111">(111)</a></h5> +<p>While processing an +end-of-input macro, the formatter assumes that the next page break must +be the last; it goes into “sudden death overtime”.</p> +<h5 class="footnote-body-heading"><a id="FOOT112" href="End_002dof_002dinput-Traps.html#DOCF112">(112)</a></h5> +<p>Another, taken by the <code class="code">groff</code> <code class="code">man</code> macros, is +to intercept <code class="code">ne</code> requests and wrap <code class="code">bp</code> ones.</p> +<h5 class="footnote-body-heading"><a id="FOOT113" href="Diversions.html#DOCF113">(113)</a></h5> +<p>Thus, the “water” +gets “higher” proceeding <em class="emph">down</em> the page.</p> +<h5 class="footnote-body-heading"><a id="FOOT114" href="Punning-Names.html#DOCF114">(114)</a></h5> +<p>The backslash is doubled. See <a class="xref" href="Copy-Mode.html">Copy Mode</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT115" href="Postprocessor-Access.html#DOCF115">(115)</a></h5> +<p>that is, ISO 646:1991-IRV or, +popularly, “US-ASCII”</p> +<h5 class="footnote-body-heading"><a id="FOOT116" href="Postprocessor-Access.html#DOCF116">(116)</a></h5> +<p>They are bypassed because these parameters are not +rendered as glyphs in the output; instead, they remain abstract +characters—in a PDF bookmark or a URL, for example.</p> +<h5 class="footnote-body-heading"><a id="FOOT117" href="Miscellaneous.html#DOCF117">(117)</a></h5> +<p>Recall <a class="ref" href="Line-Layout.html">Line Layout</a>.</p> +<h5 class="footnote-body-heading"><a id="FOOT118" href="Miscellaneous.html#DOCF118">(118)</a></h5> +<p>Historically, +tools named <code class="command">nrchbar</code> and <code class="command">changebar</code> were developed for +marking changes with margin characters and could be found in archives of +the <code class="code">comp.sources.unix</code> <abbr class="acronym">USENET</abbr> group. Some proprietary +Unices also offer(ed) a <code class="command">diffmk</code> program.</p> +<h5 class="footnote-body-heading"><a id="FOOT119" href="Gtroff-Internals.html#DOCF119">(119)</a></h5> +<p>Except the +escape sequences <code class="code">\f</code>, <code class="code">\F</code>, <code class="code">\H</code>, <code class="code">\m</code>, <code class="code">\M</code>, +<code class="code">\R</code>, <code class="code">\s</code>, and <code class="code">\S</code>, which are processed immediately if +not in copy mode.</p> +<h5 class="footnote-body-heading"><a id="FOOT120" href="Compatibility-Mode.html#DOCF120">(120)</a></h5> +<p>The +Graphic Systems C/A/T phototypesetter (the original device target for +<abbr class="acronym">AT&T</abbr> <code class="code">troff</code>) supported only a few discrete type sizes +in the range 6–36 points, so Ossanna contrived a special case in the +parser to do what the user must have meant. Kernighan warned of this in +the 1992 revision of CSTR #54 (§2.3), and more recently, McIlroy +referred to it as a “living fossil”.</p> +<h5 class="footnote-body-heading"><a id="FOOT121" href="Other-Differences.html#DOCF121">(121)</a></h5> +<p>DWB 3.3, Solaris, Heirloom Doctools, and +Plan 9 <code class="code">troff</code> all support it.</p> +<h5 class="footnote-body-heading"><a id="FOOT122" href="Other-Differences.html#DOCF122">(122)</a></h5> +<p>Naturally, if you’ve changed +the escape character, you need to prefix the <code class="code">e</code> with whatever it +is—and you’ll likely get something other than a backslash in the +output.</p> +<h5 class="footnote-body-heading"><a id="FOOT123" href="Other-Differences.html#DOCF123">(123)</a></h5> +<p>The <code class="code">rs</code> special character identifier was not +defined in <abbr class="acronym">AT&T</abbr> <code class="code">troff</code>’s font description files, but is +in those of its lineal descendant, Heirloom Doctools <code class="code">troff</code>, as of +the latter’s 060716 release (July 2006).</p> +<h5 class="footnote-body-heading"><a id="FOOT124" href="gtroff-Output.html#DOCF124">(124)</a></h5> +<p>The parser +and postprocessor for intermediate output can be found in the file<br> +<samp class="file"><var class="var">groff-source-dir</var>/src/libs/libdriver/input.cpp</samp>.</p> +<h5 class="footnote-body-heading"><a id="FOOT125" href="Device-and-Font-Description-Files.html#DOCF125">(125)</a></h5> +<p>Plan 9 <code class="code">troff</code> has also abandoned the binary +format.</p> +<h5 class="footnote-body-heading"><a id="FOOT126" href="Font-Description-File-Format.html#DOCF126">(126)</a></h5> +<p>800-point type +is not practical for most purposes, but using it enables the quantities +in the font description files to be expressed as integers.</p> +<h5 class="footnote-body-heading"><a id="FOOT127" href="Font-Description-File-Format.html#DOCF127">(127)</a></h5> +<p><code class="code">groff</code> requests and escape sequences +interpret non-negative font names as mounting positions instead. +Further, a font named ‘<samp class="samp">0</samp>’ cannot be automatically mounted by the +<code class="code">fonts</code> directive of a <samp class="file">DESC</samp> file.</p> +<h5 class="footnote-body-heading"><a id="FOOT128" href="Font-Description-File-Format.html#DOCF128">(128)</a></h5> +<p>For typesetter devices, this directive is misnamed +since it starts a list of glyphs, not characters.</p> +<h5 class="footnote-body-heading"><a id="FOOT129" href="Font-Description-File-Format.html#DOCF129">(129)</a></h5> +<p>that is, any integer parsable by the C +standard library’s <cite class="cite">strtol<span class="r">(3)</span></cite> function</p> +</div><hr> +<div class="nav-panel"> +<p> + [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Request-Index.html" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |