5 Last update: 6 Jan 2002
7 This file is part of groff, the GNU roff type-setting system.
9 Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
10 written by Bernd Warken <bwarken@mayn.de>
11 maintained by Werner Lemberg <wl@gnu.org>
13 Permission is granted to copy, distribute and/or modify this document
14 under the terms of the GNU Free Documentation License, Version 1.1 or
15 any later version published by the Free Software Foundation; with the
16 Invariant Sections being this .ig-section and AUTHORS, with no
17 Front-Cover Texts, and with no Back-Cover Texts.
19 A copy of the Free Documentation License is included as a file called
20 FDL in the main directory of the groff source package.
23 .\" --------------------------------------------------------------------
25 .\" --------------------------------------------------------------------
41 .\" --------------------------------------------------------------------
42 .\" start of macro definitions
51 .c ---------------------------------------------------------------------
54 .c All arguments are printed as text.
59 .c ---------------------------------------------------------------------
60 .c .ExecFF macro font1 font2 text1 text2 text1 text2 ...
62 .c Concat text arguments using alternating fonts and feed into macro.
63 .c For a trailing punctuation, terminate the call with \c.
78 . as @s \f[\*[@f1]]\*[@a]\f[P]\"
83 . as @s \f[\*[@f2]]\*[@a]\f[P]\"
87 . ft P \" to make \c happy
95 .c --------- command line option ---------
102 .c --------- characters ---------
105 . ExecFF Text CB R \$*
110 . ExecFF Text R CB \[oq] \*[@1] "\[cq]\$*"
116 . ExecFF Text R CB \[lq] \*[@1] "\[rq]\$*"
119 .c --------- requests ---------
121 .c synopsis of a request
127 . ie (\n[.$] = 0) \{\
129 . Text \f[CB]\*[@1]\f[P]
133 . Text \f[CB]\*[@1]\~\f[P]\f[I]\$*\f[P]
137 .c reference of a request
142 .c --------- numerical elements ---------
144 .c number with a trailing unit
146 . Text \$1\^\f[CB]\$2\f[P]\$3\f[R]
150 .c representation of units within the text
152 . Text \f[CB]\$1\f[P]\$2\f[R]
156 .c representation of mathematical operators within the text
162 .c --------- escape sequences ---------
164 .c ---------------------------------------------------------------------
167 .c Synopsis of an escape sequence, optionally with argument
168 .c Args : 1 or 2; `name' obligatory, `arg' optional
169 .c name : suitable name for an escape sequence (c, (xy, [long])
170 .c arg : arbitrary word
171 .c Result : prints \namearg, where `name' is in CB, `arg' in I
175 . ab .ESC needs 1 or 2 arguments.
176 . ExecFF IP CB I "\[rs]\$1" "\,\$2\/"
178 .c ---------------------------------------------------------------------
181 .c Synopsis for escape sequence with a bracketed long argument
182 .c Args : 2 obligatory
183 .c name : suitable name for an escape sequence (c, (xy, [long])
184 .c arg : arbitrary text
185 .c Result : prints \name[arg], where `name' is in CB, `arg' in I
189 . ab .ESC[] needs exactly 2 arguments.
190 . ExecFF IP CB I "\[rs]\$1\[lB]" "\h'-0.2m'\$2\h'-0.15m'" \[rB]
192 .c ---------------------------------------------------------------------
195 .c Synopsis for escape sequence with a bracketed long argument
196 .c Args : 2 obligatory
197 .c name : suitable name for an escape sequence (c, (xy, [long])
198 .c arg : arbitrary text
199 .c Result : prints \name'arg', where `name' is in CB, `arg' in I
203 . ab .ESCq needs exactly 2 argument.
204 . ExecFF IP CB I "\[rs]\$1\[cq]" "\h'-0.3m'\$2" \[cq]
206 .c ---------------------------------------------------------------------
209 .c Synopsis for escape sequence with a bracketed long argument
210 .c Args : 1 obligatory
211 .c arg : arbitrary text
212 .c Result : prints `\?arg?', where the `?' are in CB, `arg' in I
216 . ab .ESC? needs exactly 1 arguments.
217 . ExecFF IP CB I \[rs]? "\$1" ?
219 .c ---------------------------------------------------------------------
222 .c Reference of an escape sequence (no args), possibly punctuation
223 .c Args : 1 obligatory
224 .c name : suitable name for an escape sequence (c, (xy, [long])
226 .c Result : prints \name, where `name' is in B, `punct' in R
230 . ab .esc needs 1 or 2 arguments.
233 .c ---------------------------------------------------------------------
234 .c .escarg name arg [punct]
236 .c Reference of an escape sequence (no args)
237 .c Args : 1 obligatory, 1 optional
238 .c name : suitable name for an escape sequence (c, (xy, [long])
239 .c arg : arbitrary word
240 .c Result : prints \namearg, where
241 .c `name' is in B, `arg' in I
245 . ab .esc needs 2 or 3 arguments.
246 . Text \f[B]\[rs]\$1\f[P]\f[I]\$2\f[P]\$3
248 .c ---------------------------------------------------------------------
249 .c .esc[] name arg [punct]
251 .c Reference for escape sequence with a bracketed long argument
252 .c Args : 2 obligatory
253 .c name : suitable name for an escape sequence (c, (xy, [long])
254 .c arg : arbitrary text
255 .c Result : prints \name[arg], where `name' is in CB, `arg' in CI
259 . ab .esc[] needs 2 or 3 arguments.
260 . Text \f[B]\[rs]\$1\[lB]\f[P]\f[I]\$2\f[P]\f[B]\[rB]\f[P]\$3
263 .c ---------------------------------------------------------------------
266 .c Reference for escape sequence with a bracketed long argument
267 .c Args : 2 obligatory
268 .c name : suitable name for an escape sequence (c, (xy, [long])
269 .c arg : arbitrary text
270 .c Result : prints \name'arg', where `name' is in CB, `arg' in CI
274 . ab .escq needs 2 arguments.
275 . Text \f[B]\[rs]\$1\[cq]\f[P]\f[I]\$2\f[P]\f[B]\[cq]\f[P]\$3
278 .c --------- strings ---------
280 .c synopsis for string, with \*[]
285 . ExecFF Text R CB \[rs]*[ \*[@1]\f[P]\f[R]] \$*
288 .c synopsis for a long string
292 . Text \f[CB]\[rs]*\[lB]\$1\[rB]\f[P]\$2
296 .c --------- registers ---------
298 .c synopsis for registers, with \n[]
303 . ExecFF Text R CB \[rs]n[ \*[@1]\f[P]\f[R]] \$*
306 .c reference of a register, without decoration
313 .\" end of macro definitions
316 .\" --------------------------------------------------------------------
318 .\" --------------------------------------------------------------------
320 .TH GROFF @MAN7EXT@ "@MDATE@" "Groff Version @VERSION@"
322 groff \- a short reference for the GNU roff language
325 .\" --------------------------------------------------------------------
327 .\" --------------------------------------------------------------------
333 and is the free implementation of the roff type-setting system.
337 for a survey and the background of the groff system.
340 This document gives only short descriptions of the predefined roff
341 language elements as used in groff.
343 Both the classical features and the groff extensions are provided.
351 is compatible with the classical system and provides proper
359 could be used as synonyms.
363 slightly tends to refer more to the classical aspects, whereas
365 emphasizes the GNU extensions, and
367 is the general term for the language.
370 This file is only a short version of the complete documentation that
374 file, which contains more detailed, actual, and concise information.
377 The general syntax for writing groff documents is relatively easy, but
378 writing extensions to the roff language can be a bit harder.
381 The roff language is line-oriented.
383 There are only two kinds of lines, control lines and text lines.
385 The control lines start with a control character, by default a period
389 all other lines are text lines.
393 represent commands, optionally with arguments.
395 They have the following syntax.
397 The leading control character can be followed by a command name;
398 arguments, if any, are separated by blanks from the command name and
399 among themselves, for example,
403 .Text .command_name arg1 arg2
407 For indentation, any number of space or tab characters can be inserted
408 between the leading control character and the command name, but the
409 control character must be on the first position of the line.
413 represent the parts that will be printed.
414 They can be modified by escape sequences, which are recognized by a
416 .squoted_char \[rs] .
417 These are in-line or even in-word formatting elements or functions.
419 Some of these take arguments separated by single quotes
421 others are regulated by a length encoding introduced by an open
424 or enclosed in brackets
430 The roff language provides flexible instruments for writing language
431 extension, such as macros.
433 When interpreting macro definitions, the roff system enters a special
434 operating mode, called the
438 The copy mode behavior can be quite tricky, but there are some rules
439 that ensure a safe usage.
442 Printable backslashes must be denoted as
446 represents the current escape character.
448 To get a backslash glyph, use
453 Double all backslashes.
455 Begin all text lines with the special non-spacing character
459 This does not produce the most efficient code, but it should work as a
462 For better strategies, see the groff info file and
463 .BR groff_tmac (@MAN5EXT@).
466 Reading roff source files is easier, just reduce all double backslashes
467 to a single one in all macro definitions.
470 .\" --------------------------------------------------------------------
472 .\" --------------------------------------------------------------------
474 The roff language elements add formatting information to a text file.
476 The fundamental elements are predefined commands and variables that
477 make roff a full-blown programming language.
480 There are two kinds of roff commands, possibly with arguments.
482 are written on a line of their own starting with a dot
488 are in-line functions and in-word formatting elements starting with a
490 .squoted_char \[rs] .
493 The user can define her own formatting commands using the
497 These commands are called
499 but they are used exactly like requests.
501 Macro packages are pre-defined sets of macros written in the groff
504 A user's possibilities to create escape sequences herself is very
505 limited, only special characters can be mapped.
508 The groff language provides several kinds of variables with
509 different interfaces.
511 There are pre-defined variables, but the user can define her own
516 variables store character sequences.
518 They are set with the
520 request and retrieved by the
526 variables can store numerical values, numbers with a scale unit, and
527 occasionally string-like objects.
529 They are set with the
531 request and retrieved by the
537 allow the user to temporarily store global formatting parameters like
538 line length, font size, etc.\& for later reuse.
546 are identified either by a name or by an internal number.
548 The current font is chosen by the
554 Each device has special fonts, but the following fonts are available
557 is the standard font Roman.
567 is everywhere available, but on text devices, it is displayed as an
568 underlined Roman font.
570 For the graphical output devices, there exist constant-width pendants
576 On text devices, all characters have a constant width anyway.
579 Moreover, there are some advanced roff elements.
583 stores information into a macro for later usage.
587 is a positional condition like a certain number of lines from page top
588 or in a diversion or in the input.
590 Some action can be prescribed to be run automatically when the
594 More detailed information and examples can be found in the groff info
598 .\" --------------------------------------------------------------------
599 .SH "CONTROL CHARACTERS"
600 .\" --------------------------------------------------------------------
602 There is a small set of characters that have a special controlling
603 task in certain conditions.
607 A dot is only special at the beginning of a line or after the
608 condition in the requests
614 There it is the control character that introduces a request (or macro).
616 The special behavior can be delayed by using the
622 request, the control character can be set to a different character,
625 a non-special character.
627 In all other positions, it just means a dot character.
629 In text paragraphs, it is advantageous to start each sentence at a
634 The single quote has two controlling tasks.
636 At the beginning of a line and in the conditional requests it is the
637 non-breaking control character.
639 That means that it introduces a request like the dot, but with the
640 additional property that this request doesn't cause a linebreak.
644 request, the non-break control character can be set to a different
648 As a second task, it is the most commonly used argument separator in
649 some functional escape sequences (but any pair of characters not part
650 of the argument will work).
652 In all other positions, it denotes the single quote or apostrophe
655 Groff provides a printable representation with the
661 The double quote is used to enclose arguments in requests and macros.
666 requests, a leading double quote in the argument will be stripped off,
667 making everything else afterwards the string to be defined (enabling
670 The escaped double quote
672 introduces a comment.
674 Otherwise, it is not special.
676 Groff provides a printable representation with the
682 The backslash usually introduces an escape sequence (this can be
687 A printed version of the escape character is the
689 escape; a backslash glyph can be obtained by
693 The open parenthesis is only special in escape sequences when
694 introducing an escape name or argument consisting of exactly two
697 In groff, this behavior can be replaced by the \f[CB][]\f[P] construct.
700 The opening bracket is only special in groff escape sequences; there
701 it is used to introduce a long escape name or long escape argument.
703 Otherwise, it is non-special, e.g.\& in macro calls.
706 The closing bracket is only special in groff escape sequences; there
707 it terminates a long escape name or long escape argument.
709 Otherwise, it is non-special.
712 Space characters are only functional characters.
714 They separate the arguments in requests or macros, and the words in
717 They are subject to groff's horizontal spacing calculations.
719 To get a defined space width, escape sequences like
720 .squoted_char "\[rs]\ "
721 (this is the escape character followed by a space),
728 .IP \f[CI]newline\f[P]
729 In text paragraphs, newlines mostly behave like space characters.
731 Continuation lines can be specified by an escaped newline, i.e., by
732 specifying a backslash
734 as the last character of a line.
736 If a tab character occurs during text the interpreter makes a
737 horizontal jump to the next pre-defined tab position.
739 There is a sophisticated interface for handling tab positions.
742 .\" --------------------------------------------------------------------
743 .SH "NUMERICAL EXPRESSIONS"
744 .\" --------------------------------------------------------------------
748 is a signed or unsigned integer or float with or without an appended
753 is a one-character abbreviation for a unit of measurement.
755 A number followed by a scale indicator signifies a size value.
757 By default, numerical values do not have a scale indicator, i.e., they
763 language defines the following scale indicators.
780 Pica\ \[eq]\ 1/6\ inch
784 Point\ \[eq]\ 1/72\ inch
788 Em\ \[eq]\ \f[R]the font size in points (width of letter `\f[CR]m\f[R]')
792 100\^th \f[R]of an \f[CR]Em
800 Basic unit for actual output device
804 Vertical line space in basic units
805 scaled point\ \[eq]\ 1/\f[CI]sizescale\f[R] of a point (defined in
806 font \f[I]DESC\f[P] file)
815 .B Numerical expressions
816 are combinations of the numerical values defined above with the
817 following arithmetical operators already defined in classical troff.
881 Grouping of expressions
885 Close current grouping
893 added the following operators for numerical expressions:
900 .ExecFF Text I CB e1 >? e2
907 .ExecFF Text I CB e1 <? e2
914 .ExecFF Text CB I ( c ; e )
919 as the default scaling indicator.
925 For details see the groff info file.
928 .\" --------------------------------------------------------------------
930 .\" --------------------------------------------------------------------
933 occur in tests raised by the
940 The following table characterizes the different types of conditions.
948 A numerical expression
950 yields true if its value is greater than\~0.
962 is identical to string\~\c
969 is not identical to string\~\c
974 True if there is a character\~\c
980 True if there is a string, macro, diversion, or request called
985 Current page number is even.
989 Current page number is odd.
993 True if there is a color called
1003 True if there is a register named
1015 .\" --------------------------------------------------------------------
1017 .\" --------------------------------------------------------------------
1019 This section provides a short reference for the predefined requests.
1021 In groff, request and macro names can be arbitrarily long.
1023 No bracketing or marking of long names is needed.
1026 Most requests take one or more arguments.
1028 The arguments are separated by space characters (no tabs!); there is
1029 no inherent limit for their length or number.
1031 An argument can be enclosed by a pair of double quotes.
1033 This is very handy if an argument contains space characters, e.g.,
1034 .RI \[dq] "arg with space" \[dq]
1035 denotes a single argument.
1038 Some requests have optional arguments with a different behaviour.
1040 Not all of these details are outlined here.
1042 Refer to the groff info file and
1043 .BR groff_diff (@MAN7EXT@)
1047 In the following request specifications, most argument names were
1048 chosen to be descriptive.
1050 Only the following denotations need clarification.
1058 denotes a single character.
1062 a font either specified as a font name or a font number.
1066 all characters up to the end of the line or within
1073 is a numerical expression that evaluates to an integer value.
1077 is an arbitrary numerical expression, signed or unsigned.
1081 has three meanings depending on its sign, described below.
1087 If an expression defined as
1091 sign the resulting value of the expression will be added to an already
1092 existing value inherent to the related request, e.g.\& adding to a number
1095 If the expression starts with a
1097 the value of the expression will be subtracted from the request value.
1102 replaces the existing value directly.
1104 To assign a negative number either prepend\~0 or enclose the negative
1105 number in parentheses.
1108 .\" --------------------------------------------------------------------
1109 .SS "Request Short Reference"
1110 .\" --------------------------------------------------------------------
1115 Empty line, ignored.
1117 Useful for structuring documents.
1119 .REQ .\[rs]\[dq] anything
1120 Complete line is a comment.
1125 on standard error, exit program.
1128 Begin line adjustment for output lines in current adjust mode.
1131 Start line adjustment in mode
1133 (\f[CI]c\f[P]\f[CR]\|\^\[eq]\|l,r,b,n\f[P]).
1140 (\f[CI]c\f[P]\f[CR]\|\^\[eq]\|l,i,I,a,A\f[P]).
1142 .REQ .aln alias register
1143 Create alias name for
1146 .REQ .als alias object
1147 Create alias name for request, string, macro, or diversion
1167 but with compatibility mode switched off during macro expansion.
1172 but with compatibility mode switched off during macro expansion.
1174 .REQ .as stringvar anything
1180 .REQ .asciify diversion
1181 Unformat ASCII characters, spaces, and some escape sequences in
1185 Print a backtrace of the input on stderr.
1195 Embolden Special Font
1197 when current font is
1201 Unset the blank line macro.
1204 Set the blank line macro to
1208 End current diversion.
1213 omitting a partially filled line.
1216 End current diversion.
1219 Divert and append to
1221 omitting a partially filled line.
1224 Eject current page and begin new page.
1227 Eject current page; next page number
1234 Break and spread output line.
1239 Break out of a while loop.
1242 Reset no-break control character to
1246 Set no-break control character to
1250 Reset control character to
1254 Set control character to
1258 Center the next input line.
1266 Copy contents of file
1268 unprocessed to stdout or to the diversion.
1270 .REQ .cflags mode c1 c2 .\|.\|.\&
1286 .REQ .char c anything
1293 Chop the last character off macro, string, or diversion
1301 Finish the current iteration of a while loop.
1304 Enable compatibility mode.
1309 is zero disable compatibility mode, otherwise enable it.
1312 Set constant character width mode for
1320 Continuous underline in nroff, like
1325 End current diversion.
1328 Divert and append to
1348 but with compatibility mode switched off during macro expansion.
1353 but with compatibility mode switched off during macro expansion.
1355 .REQ .defcolor color scheme component
1356 Define or redefine a color with name
1367 can be single components specified as fractions in the range 0 to 1
1368 (default scale indicator\~\c
1369 .scaleindicator f ),
1370 as a string of two-digit hexadecimal color components with a leading
1372 or as a string of four-digit hexadecimal components with two leading
1376 Define or redefine a macro whose name is contained in the string register
1383 Define or redefine a macro indirectly.
1387 are string registers whose contents are interpolated for the macro name
1388 and the end macro, respectively.
1391 End current diversion.
1400 with compatibility mode disabled.
1402 .REQ .ds stringvar anything
1409 Set diversion trap to position
1411 (default scale indicator\~\c
1412 .scaleindicator v ).
1415 Reset escape character to
1416 .squoted_char \[rs] .
1419 Set escape character to
1423 Restore escape character saved with
1427 Save current escape character.
1430 Else part for if-else (\c
1437 will be run after the end of input.
1440 Turn off escape character mechanism.
1443 Switch to previous environment.
1446 Push down environment number or name
1451 Copy the contents of environment
1453 to the current environment.
1454 No pushing or popping.
1457 Exit from roff processing.
1460 Return to previous font family.
1463 Set the current font family to
1467 Disable field mechanism.
1470 Set field delimiter to
1472 and pad character to space.
1475 Set field delimiter to
1477 and pad character to
1480 .REQ .fchar c anything
1481 Define fallback character
1490 Flush output buffer.
1498 .REQ .fp n internal external
1499 Mount font with long
1506 .REQ .fspecial font s1 s2 .\|.\|.\&
1507 When the current font is
1516 Return to previous font.
1520 Change to font name or number
1526 .REQ .ftr font1 font2
1533 Remove additional hyphenation indicator character.
1536 Set up additional hyphenation indicator character\~\c
1539 .REQ .hcode c1 code1 c2 code2 .\|.\|.\&
1540 Set the hyphenation code of character
1551 Set the current hyphenation language to
1555 Set the maximum number of consecutive hyphenated lines to
1559 Read hyphenation patterns from
1565 with exceptional hyphenation.
1568 Switch to hyphenation mode
1572 Set the hyphenation margin to
1574 (default scale indicator\~\c
1575 .scaleindicator m ).
1578 Set the hyphenation space to
1581 .REQ .ie cond anything
1589 .REQ .if cond anything
1594 otherwise do nothing.
1606 Change to previous indent value.
1609 Change indent according to
1611 (default scale indicator\~\c
1612 .scaleindicator m ).
1615 Set an input-line count trap for the next
1622 but count lines interrupted with
1627 Enable pairwise kerning.
1632 is zero, disable pairwise kerning, otherwise enable it.
1635 Remove leader repetition character.
1638 Set leader repetition character to\~\c
1641 .REQ .length register anything
1642 Write the length of the string
1648 Enable line-tabs mode (i.e., calculate tab positions relative to output
1654 is zero, disable line-tabs mode, otherwise enable it.
1657 Set input line number to
1667 Change to previous line length.
1670 Set line length according to
1673 .scalednumber 6.5 i ,
1674 default scale indicator\~\c
1675 .scaleindicator m ).
1678 Change to the previous value of additional intra-line skip.
1681 Set additional intra-line skip value to
1685 blank lines are inserted after each text output line.
1688 Length of title (default scale indicator\~\c
1689 .scaleindicator m ).
1692 Margin character off.
1697 after each text line at actual distance from right margin.
1700 Set margin character to
1704 from right margin (default scale indicator\~\c
1705 .scaleindicator m ).
1708 Mark current vertical position in
1712 The same as the .so request except that
1714 is searched in the tmac directories.
1717 No output-line adjusting.
1720 Need a one-line vertical space.
1725 vertical space (default scale indicator\~\c
1726 .scaleindicator v ).
1729 No filling or adjusting of output-lines.
1737 .REQ .nm \[+-]N M S I
1738 In line number mode, set number, multiple, spacing, and indent.
1741 Do not number next line.
1752 .REQ .nr register \[+-]N M
1761 Make the built-in condition
1768 Turn no-space mode on.
1773 .REQ .open stream filename
1776 for writing and associate the stream named
1780 .REQ .opena stream filename
1786 Output vertical distance that was saved by the
1791 Reset page number character to\~\c
1795 Page number character.
1803 Set page length to default
1804 .scalednumber 11 i .
1805 The current page length is stored in
1809 Change page length to
1811 (default scale indicator\~\c
1812 .scaleindicator v ).
1815 Print macro names and sizes (number of blocks of 128 bytes).
1818 Print only total of sizes of macros (number of 128 bytes blocks).
1825 Print the names and contents of all currently defined number registers
1829 Change to previous page offset.
1831 The current page offset is available in
1839 Return to previous point-size.
1845 Get the bounding box of a PostScript image
1849 This behaves like the
1851 request except that input comes from the standard output of
1855 Print the names and positions of all traps (not including input line
1856 traps and diversion traps) on stderr.
1858 .REQ .rchar c1 c2 .\|.\|.\&
1859 Remove the definitions of characters
1868 Return from a macro.
1871 Right justify the next
1876 Remove request, macro, or string
1880 Rename request, macro, or string
1896 Restore spacing; turn no-space mode off.
1901 to marked vertical place (default scale indicator\~\c
1902 .scaleindicator v ).
1905 Reset soft hyphen character to
1909 Set the soft hyphen character to
1913 In a macro, shift the arguments by
1918 Include source file.
1921 Skip one line vertically.
1924 Space vertical distance
1926 up or down according to sign of
1928 (default scaling indicator\~\c
1929 .scaleindicator v ).
1931 .REQ .special s1 s2 .\|.\|.\&
1935 etc.\& are special and will be searched for characters not in the
1939 Space-character size set to
1941 of the spacewidth in the current font.
1944 Space-character size set to
1946 and sentence space size set to
1948 of the spacewidth in the current font (\f[CR]\[eq]1/3 em\f[P]).
1956 .REQ .substring register n1 n2
1957 Replace the string in
1959 with the substring defined by the indices
1970 Save the vertical distance
1972 for later output with
1976 .REQ .sy command-line
1981 Set tabs after every position that is a multiple of
1983 (default scaling indicator\~\c
1984 .scaleindicator m ).
1985 .REQ .ta n1 n2 .\|.\|.\& nn \f[CB]T\f[P] r1 r2 .\|.\|.\& rn
1986 Set tabs at positions
2004 .\"Restore internally saved tab positions.
2007 .\"Save tab positions internally.
2010 Remove tab repition character.
2012 Set tab repetition character to\~\c
2016 Temporary indent next line (default scaling indicator\~\c
2017 .scaleindicator m ).
2019 .REQ .tkf font s1 n1 s2 n2
2020 Enable track kerning for
2023 .REQ .tl \f[CB]\[cq]\f[P]left\f[CB]\[cq]\f[P]center\f[CB]\[cq]\f[P]right\f[CB]\[cq]\f[P]
2029 on terminal (UNIX standard message output).
2034 on terminal (UNIX standard message output), allowing leading
2039 (which will be stripped off).
2044 without emitting a final newline.
2046 .REQ .tr abcd.\|.\|.\&
2057 Transparently output the contents of file
2060 .REQ .trnt abcd.\|.\|.\&
2061 This is the same as the
2063 request except that the translations do not apply to text that is
2064 transparently throughput into a diversion with
2068 Make the built-in condition
2075 Underline font set to
2077 (to be switched to by
2081 Underline (italicize in troff)
2085 .REQ .unformat diversion
2086 Unformat space characters and tabs, preserving font information in
2089 Enable vertical position traps if
2091 is non-zero, disable them otherwise.
2094 Change to previous vertical base line spacing.
2097 Set vertical base line spacing to
2100 .scalednumber 12 p .
2103 Set warnings code to
2107 Set location trap; negative means from page bottom.
2109 .REQ .while cond anything
2116 .REQ .write stream anything
2125 Besides these standard groff requests, there might be further macro
2127 They can originate from a macro package (see
2128 .BR roff (@MAN7EXT@)
2129 for an overview) or from a preprocessor.
2132 Preprocessor macros are easy to be recognized.
2134 They enclose their code into a pair of characteristic macros.
2138 box, center, tab (@);
2141 preprocessor@start macro@ end macro
2148 soelim@\f[I]none@\f[I]none
2154 .\" --------------------------------------------------------------------
2155 .SH "ESCAPE SEQUENCES"
2156 .\" --------------------------------------------------------------------
2158 Escape sequences are in-line language elements usually introduced by a
2161 and followed by an escape name and sometimes by a required argument.
2163 Input processing is continued directly after the escaped character or
2164 the argument resp.\& without an intervening separation character.
2166 So there must be a way to determine the end of the escape name and the
2167 end of the argument.
2170 This is done by enclosing names (escape name and arguments consisting
2171 of a variable name) by a pair of brackets
2172 .BI \[lB] name \[rB]
2173 and constant arguments (number expressions and characters) by
2174 apostrophes (ASCII 0x27) like
2175 .BI \[cq] constant \[cq] \f[R].
2178 There are abbreviations for short names.
2180 Two character escape names can be specified by an opening parenthesis
2183 without a closing counterpart.
2185 And all one-character names different from the special characters
2189 can even be specified without a marker in the form
2193 Constant arguments of length\~1 can omit the marker apostrophes, too,
2194 but there is no two-character analogue.
2197 While 1-character escape sequences are mainly used for in-line
2198 functions and system related tasks, the 2-letter names following the
2200 construct are used for special characters predefined by the roff system.
2202 Escapes sequences with names of more than two characters
2204 denote user defined named characters (see the
2209 .\" --------------------------------------------------------------------
2210 .SS "Single Character Escapes"
2211 .\" --------------------------------------------------------------------
2215 .\" --------- comments ---------
2218 Beginning of a comment.
2220 Everything up to the end of the line is ignored.
2223 Everything up to and including the next newline is ignored.
2225 This is interpreted in copy mode.
2229 except that the terminating newline is ignored as well.
2231 .\" --------- strings ---------
2234 The string stored in the string variable with 1-character name
2238 The string stored in the string variable with 2-character name
2242 The string stored in the string variable with arbitrary length name
2245 .\" --------- macro arguments ---------
2248 The name by which the current macro was invoked.
2252 request can make a macro have more than one name.
2255 Macro argument with 1-place number
2259 is a digit between 1 and 9.
2262 Macro argument with 2-digit number
2266 Macro argument with number
2270 is a numerical expression evaluating to an integer \[>=]1.
2273 In a macro, the concatenation of all the arguments separated by spaces.
2276 In a macro, the concatenation of all the arguments with each surrounded
2277 by double quotes, and separated by spaces.
2279 .\" --------- escaped characters ---------
2282 reduces to a single backslash; useful to delay its interpretation as
2283 escape character in copy mode.
2285 For a printable backslash, use
2289 The acute accent \[aa]; same as
2291 Unescaped: apostrophe, right quotation mark, single quote (ASCII 0x27).
2294 The grave accent \[ga]; same as
2296 Unescaped: left quote, backquote (ASCII 0x60).
2299 The \- sign in the current font.
2302 An uninterpreted dot (period), even at start of line.
2305 Default optional hyphenation character.
2308 Transparent line indicator.
2311 In a diversion, this will transparently embed
2315 is read in copy mode.
2317 See also the escape sequences
2323 .\" --------- spacing ---------
2326 Unpaddable space-size space character (no line break).
2332 1/6\ em narrow space character; zero width in nroff.
2335 1/12\ em half-narrow space character; zero width in nroff.
2338 Non-printable, zero width character.
2343 except that it behaves like a character declared with the cflags
2344 request to be transparent for the purposes of end of sentence
2348 Increases the width of the preceding character so that the spacing
2349 between that character and the following character will be correct if
2350 the following character is a roman character.
2353 Modifies the spacing of the following character so that the spacing
2354 between that character and the preceding character will correct if the
2355 preceding character is a roman character.
2358 Unbreakable space that stretches like a normal inter-word space when a
2362 Inserts a zero-width break point (similar to
2364 but without a soft hyphen character).
2367 Ignored newline, for continuation lines.
2369 .\" --------- structuring ---------
2372 Begin conditional input.
2375 End conditional input.
2377 .\" --------- longer escape names ---------
2380 The special character with 2-character name
2383 .BR "Special Characters" .
2386 The named character with arbitrary length name
2389 .\" --------- alphabetical escapes ---------
2392 Non-interpreted leader character.
2397 is acceptable as a name of a string, macro, diversion, register,
2398 environment or font it expands to\~1, and to\~0 otherwise.
2400 .ESCq b abc.\|.\|.\&
2401 Bracket building function.
2406 is acceptable as a valid numeric expression it expands to\~1, and
2410 Interrupt text processing.
2413 The character called
2417 but compatible to other roff versions.
2420 Forward (down) 1/2 em vertical unit (1/2 line in nroff).
2423 Draw a graphical element defined by the characters in
2425 see groff info file for details.
2428 Printable version of the current escape character.
2431 Equivalent to an escape character, but is not interpreted in copy-mode.
2434 Change to font with 1-character name or 1-digit number
2438 Change to font with 2-characer name or 2-digit number
2442 Change to font with arbitrary length name or number expression
2446 Return format of register with name
2456 Local horizontal motion; move right
2461 Set height of current font to
2465 Mark horizontal input place in register with arbitrary length name
2473 Horizontal line drawing function (optionally using character
2477 Vertical line drawing function (optionally using character
2490 Change filling color for closed drawn objects to color
2499 The numerical value stored in the register variable with the
2504 The numerical value stored in the register variable with the
2509 The numerical value stored in the register variable with arbitrary
2514 Typeset the character with code
2516 in the current font, no special fonts are searched.
2518 Useful for adding characters to a font using the
2522 .ESCq o abc.\|.\|.\&
2523 Overstrike characters
2530 Disable glyph output.
2532 Mainly for internal use.
2535 Enable glyph output.
2537 Mainly for internal use.
2540 Break and spread output line.
2543 Reverse 1\ em vertical motion (reverse line in nroff).
2545 .ESCq R "name\~\[+-]n"
2552 Set the point size to
2556 Note the alternative forms
2557 .BI \[rs]s \[+-] [ N ]\c
2559 .BI \[rs]s' \[+-]N '\c
2561 .BI \[rs]s \[+-] ' N '\c
2563 .escarg s( \[+-]xy\c
2565 .BI \[rs]s \[+-] ( xy\c
2578 Non-interpreted horizontal tab.
2581 Reverse (up) 1/2 em vertical motion (1/2 line in nroff).
2584 Local vertical motion; move down
2589 The contents of the environment variable
2598 The width of the character sequence
2602 Extra line-space function (negative before, positive after).
2607 as device control function.
2610 Output string variable or macro
2612 uninterpreted as device control function.
2622 with zero width (without spacing).
2627 and then restore the horizontal and vertical position;
2629 may not contain tabs or leaders.
2633 The escape sequences
2645 are interpreted in copy mode.
2648 Escape sequences starting with
2652 do not represent single character escape sequences, but introduce escape
2653 names with two or more characters.
2656 If a backslash is followed by a character that does not constitute a
2657 defined escape sequence the backslash is silently ignored and the
2658 character maps to itself.
2661 .\" --------------------------------------------------------------------
2662 .SS "Special Characters"
2663 .\" --------------------------------------------------------------------
2665 Common special characters are predefined by escape sequences of the
2673 Some of these exist in the usual font while most of them are only
2674 available in the special font.
2676 Below you'll find a selection of the most important glyphs; a complete
2677 list can be found in
2678 .BR groff_char (@MAN7EXT@).
2696 Printable double quote
2704 Printable backslash character
2727 .\" --------------------------------------------------------------------
2729 .\" --------------------------------------------------------------------
2731 Strings are defined by the
2733 request and can be retrieved by the
2738 Strings share their name space with macros.
2740 So strings and macros without arguments are roughly equivalent, though
2741 calling a string like a macro and vice-versa is not stably implemented
2744 The following strings are predefined in groff.
2747 The name of the current output device as specified by the
2749 command line option.
2752 .\" --------------------------------------------------------------------
2754 .\" --------------------------------------------------------------------
2756 Registers are variables that store a value.
2757 In groff, most registers store numerical values (see section
2758 .B NUMERICAL EXPRESSIONS
2759 above), but some can also hold a string value.
2762 Each register is given a name.
2763 Arbitrary registers can be defined and set with the request
2768 The value stored in a register can be retrieved by the escape sequences
2773 Most useful are predefined registers.
2775 In the following the notation
2777 is used to refer to a register called
2779 to make clear that we speak about registers.
2781 Please keep in mind that the
2783 decoration is not part of the register name.
2786 .\" --------------------------------------------------------------------
2787 .SS "Read-only Registers"
2788 .\" --------------------------------------------------------------------
2790 The following registers have predefined values that should not be
2791 modified by the user (usually, registers starting with a dot a
2794 Mostly, they provide information on the current settings or store
2795 results from request calls.
2801 Number of arguments in the current macro.
2804 Post-line extra line-space most recently utilized using
2812 is used; always\~1 in
2816 Current input line number.
2819 1\~if compatibility mode is in effect, 0\~otherwise.
2822 The depth of the last character added to the current environment.
2823 It is positive if the character extends below the baseline.
2826 The number of lines remaining to be centered, as set by the
2831 The height of the last character added to the current environment.
2832 It is positive if the character extends above the baseline.
2835 The skew of the last character added to the current environment.
2836 The skew of a character is how far to the right of the center of a character
2837 the center of an accent over that character should be placed.
2840 Current vertical place in current diversion; equal to register
2844 The name or number of the current environment (string-valued).
2847 Current font number.
2850 The current font family (string-valued).
2853 The current (internal) real font name (string-valued).
2856 The number of the next free font position.
2859 Always 1 in GNU troff.
2861 Macros should use it to test if running under groff.
2864 Text base-line high-water mark on current page or diversion.
2867 Available horizontal resolution in basic units.
2870 The current hyphenation language as set by the
2875 The number of immediately preceding consecutive hyphenated lines.
2878 The maximum allowed number of consecutive hyphenated lines, as set by
2884 The current hyphenation flags (as set by the
2889 The current hyphenation margin (as set by the
2894 The current hyphenation space (as set by the
2902 The indent that applies to the current output line.
2905 Positive if last output line contains
2909 1\~if pairwise kerning is enabled, 0\~otherwise.
2912 Current line length.
2915 The current ligature mode (as set by the
2920 The current line-tabs mode (as set by the
2925 The line length that applies to the current output line.
2928 The title length (as set by the
2933 Length of text portion on previous output line.
2936 The amount of space that was needed in the last
2938 request that caused a trap to be sprung.
2940 Useful in conjunction with
2944 1\~if in no-space mode, 0\~otherwise.
2947 Current page offset.
2950 Current page length.
2953 The number of the next page: either the value set by a
2955 request, or the number of the current page plus\ 1.
2958 The current pointsize in scaled points.
2961 The last-requested pointsize in scaled points.
2964 The number of lines to be right-justified as set by the rj request.
2967 Current point size as a decimal fraction.
2970 The last requested pointsize in points as a decimal fraction
2974 Distance to the next trap.
2983 A string representation of the current tab settings suitable for use
2984 as an argument to the
2989 The amount of vertical space truncated by the most recently sprung
2990 vertical position trap, or, if the trap was sprung by a
2992 request, minus the amount of vertical motion produced by
2995 In other words, at the point a trap is sprung, it represents
2996 the difference of what the vertical position would have been but for
2997 the trap, and what the vertical position actually is.
2999 Useful in conjunction with the
3004 The value of the parameters set by the first argument of the
3009 The value of the parameters set by the second argument of the
3014 Equal to 1 bin fill mode and 0 in nofill mode.
3017 Current vertical line spacing.
3020 Available vertical resolution in basic units.
3023 1\~ if vertical position traps are enabled, 0\~otherwise.
3026 Width of previous character.
3029 The sum of the number codes of the currently enabled warnings.
3032 The major version number.
3035 The minor version number.
3038 The revision number of groff.
3041 Name of current diversion.
3045 .\" --------------------------------------------------------------------
3046 .SS "Writable Registers"
3047 .\" --------------------------------------------------------------------
3049 The following registers can be read and written by the user.
3050 They have predefined default values, but these can be modified for
3051 customizing a document.
3056 Current page number.
3059 Current input line number.
3062 Character type (set by width function
3066 Maximal width of last completed diversion.
3069 Height of last completed diversion.
3072 Current day of week (1-7).
3075 Current day of month (1-31).
3078 Current horizontal position at input line.
3081 Lower left x-coordinate (in PostScript units) of a given PostScript
3086 Lower left y-coordinate (in PostScript units) of a given PostScript
3094 Current month (1-12).
3097 Vertical position of last printed text base-line.
3102 but takes account of the heights and depths of characters.
3107 but takes account of the heights and depths of characters.
3110 Depth of string below base line (generated by width function
3114 Right skip width from the center of the last character in the
3119 If greater than 0, the maximum number of objects on the input stack.
3121 If \[<=]0 there is no limit, i.e., recursion can continue until virtual
3122 memory is exhausted.
3125 The amount of horizontal space (possibly negative) that should be
3126 added to the last character before a subscript (generated by width
3131 Height of string above base line (generated by width function
3135 The return value of the
3137 function executed by the last
3142 Upper right x-coordinate (in PostScript units) of a given PostScript
3147 Upper right y-coordinate (in PostScript units) of a given PostScript
3152 The current year (year 2000 compliant).
3155 Current year minus 1900.
3157 For Y2K compliance use register
3164 .\" --------------------------------------------------------------------
3166 .\" --------------------------------------------------------------------
3168 The differences of the groff language in comparison to classical troff
3172 .BR groff_diff (@MAN7EXT@).
3175 The groff system provides a compatibility mode, see
3176 .BR groff (@MAN1EXT@)
3177 on how to invoke this.
3180 .\" --------------------------------------------------------------------
3182 .\" --------------------------------------------------------------------
3185 .URL "groff bug mailing list" mailto:\:bug-groff@gnu.org .
3186 Include a complete, self-contained example that will allow the bug to
3187 be reproduced, and say which version of groff you are using.
3190 .\" --------------------------------------------------------------------
3192 .\" --------------------------------------------------------------------
3194 Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
3197 This document is distributed under the terms of the FDL (GNU Free
3198 Documentation License) version 1.1 or later.
3200 You should have received a copy of the FDL on your system, it is also
3201 available on-line at the
3202 .URL "GNU copyleft site" http://\:www.gnu.org/\:copyleft/\:fdl.html .
3205 This document is part of
3207 the GNU roff distribution.
3210 .URL "Bernd Warken" mailto:\:bwarken@mayn.de ;
3212 .URL "Werner Lemberg" mailto:\:wl@gnu.org .
3215 .\" --------------------------------------------------------------------
3217 .\" --------------------------------------------------------------------
3220 The main source of information for the groff language is the
3225 Besides the gory details, it contains many examples.
3228 .BR groff (@MAN1EXT@)
3229 the usage of the groff program and pointers to the documentation and
3230 availability of the groff system.
3233 .BR groff_diff (@MAN7EXT@)
3234 the differences of the groff language as compared to classical roff.
3236 This is the authoritative document for the predefined language
3237 elements that are specific to groff.
3240 .BR groff_char (@MAN7EXT@)
3241 the predefined groff characters (glyphs).
3244 .BR groff_font (@MAN5EXT@)
3245 the specification of fonts and the DESC file.
3248 .BR roff (@MAN7EXT@)
3249 the history of roff, the common parts shared by all roff systems, and
3250 pointers to further documentation.
3254 .URL "Nroff/\:Troff User's Manual by Osanna & Kernighan" \
3255 http://\:cm.bell-labs.com/\:cm/\:cs/\:54.ps
3256 \[em] the bible for classical troff.
3259 .\" --------------------------------------------------------------------
3261 .\" --------------------------------------------------------------------
3263 .\" Local Variables: