1GROFF(7) Miscellaneous Information Manual GROFF(7)
2
6 groff - a short reference for the GNU roff language
7
9 The name groff stands for GNU roff and is the free implementation of
10 the roff type-setting system. See roff(7) for a survey and the back‐
11 ground of the groff system.
12 This document gives only short descriptions of the predefined roff lan‐
14 guage elements as used in groff. Both the classical features and the
15 groff extensions are provided.
16 Historically, the roff language was called troff. groff is compatible
18 with the classical system and provides proper extensions. So in GNU,
19 the terms roff, troff, and groff language could be used as synonyms.
20 However troff slightly tends to refer more to the classical aspects,
21 whereas groff emphasizes the GNU extensions, and roff is the general
22 term for the language.
23 This file is only a short version of the complete documentation that is
25 found in the groff info(1) file, which contains more detailed, actual,
26 and concise information.
27 The general syntax for writing groff documents is relatively easy, but
29 writing extensions to the roff language can be a bit harder.
30 The roff language is line-oriented. There are only two kinds of lines,
32 control lines and text lines. The control lines start with a control
33 character, by default a period “.” or a single quote “'”; all other
34 lines are text lines.
35 Control lines represent commands, optionally with arguments. They have
37 the following syntax. The leading control character can be followed by
38 a command name; arguments, if any, are separated by spaces (but not tab
39 characters) from the command name and among themselves, for example,
40 .command_name arg1 arg2
42 For indentation, any number of space or tab characters can be inserted
44 between the leading control character and the command name, but the
45 control character must be on the first position of the line.
46 Text lines represent the parts that is printed. They can be modified
48 by escape sequences, which are recognized by a leading backslash ‘\’.
49 These are in-line or even in-word formatting elements or functions.
50 Some of these take arguments separated by single quotes “'”, others are
51 regulated by a length encoding introduced by an open parenthesis ‘(’ or
52 enclosed in brackets ‘[’ and ‘]’.
53 The roff language provides flexible instruments for writing language
55 extension, such as macros. When interpreting macro definitions, the
56 roff system enters a special operating mode, called the copy mode.
57 The copy mode behavior can be quite tricky, but there are some rules
59 that ensure a safe usage.
60 1. Printable backslashes must be denoted as \e. To be more pre‐
62 cise, \e represents the current escape character. To get a
63 backslash glyph, use \(rs or \[rs].
64 2. Double all backslashes.
66 3. Begin all text lines with the special non-spacing character \&.
68 This does not produce the most efficient code, but it should work as a
70 first measure. For better strategies, see the groff info file and
71 groff_tmac(5).
72 Reading roff source files is easier, just reduce all double backslashes
74 to a single one in all macro definitions.
75
77 The roff language elements add formatting information to a text file.
78 The fundamental elements are predefined commands and variables that
79 make roff a full-blown programming language.
80 There are two kinds of roff commands, possibly with arguments.
82 Requests are written on a line of their own starting with a dot ‘.’ or
83 a “'”, whereas Escape sequences are in-line functions and in-word for‐
84 matting elements starting with a backslash ‘\’.
85 The user can define her own formatting commands using the de request.
87 These commands are called macros, but they are used exactly like
88 requests. Macro packages are pre-defined sets of macros written in the
89 groff language. A user's possibilities to create escape sequences her‐
90 self is very limited, only special characters can be mapped.
91 The groff language provides several kinds of variables with different
93 interfaces. There are pre-defined variables, but the user can define
94 her own variables as well.
95 String variables store character sequences. They are set with the ds
97 request and retrieved by the \* escape sequences. Strings can have
98 variables.
99 Register variables can store numerical values, numbers with a scale
101 unit, and occasionally string-like objects. They are set with the nr
102 request and retrieved by the \n escape sequences.
103 Environments allow the user to temporarily store global formatting
105 parameters like line length, font size, etc. for later reuse. This is
106 done by the ev request.
107 Fonts are identified either by a name or by an internal number. The
109 current font is chosen by the ft request or by the \f escape sequences.
110 Each device has special fonts, but the following fonts are available
111 for all devices. R is the standard font Roman. B is its bold counter‐
112 part. The italic font is called I and is available everywhere, but on
113 text devices it is displayed as an underlined Roman font. For the
114 graphical output devices, there exist constant-width pendants of these
115 fonts, CR, CI, and CB. On text devices, all glyphs have a constant
116 width anyway.
117 Glyphs are visual representation forms of characters. In groff, the
119 distinction between those two elements is not always obvious (and a
120 full discussion is beyond the scope of this man page). A first approx‐
121 imation is that glyphs have a specific size and colour and are taken
122 from a specific font; they can't be modified any more – characters are
123 the input, and glyphs are the output. As soon as an output line has
124 been generated, it no longer contains characters but glyphs. In this
125 man page, we use either `glyph' or `character', whatever is more appro‐
126 priate.
127 Moreover, there are some advanced roff elements. A diversion stores
129 (formatted) information into a macro for later usage. A trap is a
130 positional condition like a certain number of lines from page top or in
131 a diversion or in the input. Some action can be prescribed to be run
132 automatically when the condition is met.
133 More detailed information and examples can be found in the groff info
135 file.
136
138 There is a small set of characters that have a special controlling task
139 in certain conditions.
140 . A dot is only special at the beginning of a line or after the
142 condition in the requests if, ie, el, and while. There it is
143 the control character that introduces a request (or macro). The
144 special behavior can be delayed by using the \. escape. By
145 using the cc request, the control character can be set to a dif‐
146 ferent character, making the dot ‘.’ a non-special character.
147 In all other positions, it just means a dot character. In text
149 paragraphs, it is advantageous to start each sentence at a line
150 of its own.
151 ' The single quote has two controlling tasks. At the beginning of
153 a line and in the conditional requests it is the non-breaking
154 control character. That means that it introduces a request like
155 the dot, but with the additional property that this request
156 doesn't cause a linebreak. By using the c2 request, the non-
157 break control character can be set to a different character.
158 As a second task, it is the most commonly used argument separa‐
160 tor in some functional escape sequences (but any pair of charac‐
161 ters not part of the argument do work). In all other positions,
162 it denotes the single quote or apostrophe character. Groff pro‐
163 vides a printable representation with the \(cq escape sequence.
164 " The double quote is used to enclose arguments in macros (but not
166 in requests and strings). In the ds and as requests, a leading
167 double quote in the argument is stripped off, making everything
168 else afterwards the string to be defined (enabling leading
169 whitespace). The escaped double quote \" introduces a comment.
170 Otherwise, it is not special. Groff provides a printable repre‐
171 sentation with the \(dq escape sequence.
172 \ The backslash usually introduces an escape sequence (this can be
174 changed with the ec request). A printed version of the escape
175 character is the \e escape; a backslash glyph can be obtained by
176 \(rs.
177 ( The open parenthesis is only special in escape sequences when
179 introducing an escape name or argument consisting of exactly two
180 characters. In groff, this behavior can be replaced by the []
181 construct.
182 [ The opening bracket is only special in groff escape sequences;
184 there it is used to introduce a long escape name or long escape
185 argument. Otherwise, it is non-special, e.g. in macro calls.
186 ] The closing bracket is only special in groff escape sequences;
188 there it terminates a long escape name or long escape argument.
189 Otherwise, it is non-special.
190 space Space characters are only functional characters. They separate
192 the arguments in requests, macros, and strings, and the words in
193 text lines. They are subject to groff's horizontal spacing cal‐
194 culations. To get a defined space width, escape sequences like
195 ‘\ ’ (this is the escape character followed by a space), \|, \^,
196 or \h should be used.
197 newline
199 In text paragraphs, newlines mostly behave like space charac‐
200 ters. Continuation lines can be specified by an escaped new‐
201 line, i.e., by specifying a backslash ‘\’ as the last character
202 of a line.
203 tab If a tab character occurs during text the interpreter makes a
205 horizontal jump to the next pre-defined tab position. There is
206 a sophisticated interface for handling tab positions.
207
209 A numerical value is a signed or unsigned integer or float with or
210 without an appended scaling indicator. A scaling indicator is a one-
211 character abbreviation for a unit of measurement. A number followed by
212 a scaling indicator signifies a size value. By default, numerical val‐
213 ues do not have a scaling indicator, i.e., they are normal numbers.
214 The roff language defines the following scaling indicators.
216 c Centimeter
218 i Inch
219 P Pica = 1/6 inch
220 p Point = 1/72 inch
221 m Em = the font size in points (approx. width of letter
222 `m')
223 M 100th of an Em
224 n En = Em/2
225 u Basic unit for actual output device
226 v Vertical line space in basic units scaled
227 point = 1/sizescale of a point (defined in font DESC
228 file)
229 f Scale by 65536.
230 Numerical expressions are combinations of the numerical values defined
232 above with the following arithmetical operators already defined in
233 classical troff.
234 + Addition
236 - Subtraction
237 * Multiplication
238 / Division
239 % Modulo
240 = Equals
241 == Equals
242 < Less than
243 > Greater than
244 <= Less or equal
245 >= Greater or equal
246 & Logical and
247 : Logical or
248 ! Logical not
249 ( Grouping of expressions
250 ) Close current grouping
251 Moreover, groff added the following operators for numerical expres‐
253 sions:
254 e1>?e2 The maximum of e1 and e2.
256 e1<?e2 The minimum of e1 and e2.
257 (c;e) Evaluate e using c as the default scaling indicator.
258 For details see the groff info file.
260
262 Conditions occur in tests raised by the if, ie, and the while requests.
263 The following table characterizes the different types of conditions.
264 N A numerical expression N yields true if its value is
266 greater than 0.
267 !N True if the value of I is 0.
268 's1's2' True if string s1 is identical to string s2.
269 !'s1's2' True if string s1 is not identical to string s2.
270 cch True if there is a glyph ch available.
271 dname True if there is a string, macro, diversion, or
272 request called name.
273 e Current page number is even.
274 o Current page number is odd.
275 mname True if there is a color called name.
276 n Formatter is nroff.
277 rreg True if there is a register named reg.
278 t Formatter is troff.
279 Ffont True if there exists a font named font.
280 Sstyle True if a style named style has been registered.
281
283 This section provides a short reference for the predefined requests.
284 In groff, request, macro, and string names can be arbitrarily long. No
285 bracketing or marking of long names is needed.
286 Most requests take one or more arguments. The arguments are separated
288 by space characters (no tabs!); there is no inherent limit for their
289 length or number.
290 Some requests have optional arguments with a different behaviour. Not
292 all of these details are outlined here. Refer to the groff info file
293 and groff_diff(7) for all details.
294 In the following request specifications, most argument names were cho‐
296 sen to be descriptive. Only the following denotations need clarifica‐
297 tion.
298 c denotes a single character.
300 font a font either specified as a font name or a font num‐
301 ber.
302 anything all characters up to the end of the line or within \{
303 and \}.
304 n is a numerical expression that evaluates to an integer
305 value.
306 N is an arbitrary numerical expression, signed or
307 unsigned.
308 ±N has three meanings depending on its sign, described
309 below.
310 If an expression defined as ±N starts with a ‘+’ sign the resulting
312 value of the expression is added to an already existing value inherent
313 to the related request, e.g. adding to a number register. If the
314 expression starts with a ‘-’ the value of the expression is subtracted
315 from the request value.
316 Without a sign, N replaces the existing value directly. To assign a
318 negative number either prepend 0 or enclose the negative number in
319 parentheses.
320 Request Short Reference
322 . Empty line, ignored. Useful for structuring documents.
323 .\" anything
324 Complete line is a comment.
325 .ab string
326 Print string on standard error, exit program.
327 .ad Begin line adjustment for output lines in current adjust
328 mode.
329 .ad c Start line adjustment in mode c (c=l,r,b,n).
330 .af register c
331 Assign format c to register (c=l,i,I,a,A).
332 .aln alias register
333 Create alias name for register.
334 .als alias object
335 Create alias name for request, string, macro, or diversion
336 object.
337 .am macro Append to macro until .. is encountered.
338 .am macro end
339 Append to macro until .end is called.
340 .am1 macro
341 Same as .am but with compatibility mode switched off during
342 macro expansion.
343 .am1 macro end
344 Same as .am but with compatibility mode switched off during
345 macro expansion.
346 .ami macro
347 Append to a macro whose name is contained in the string reg‐
348 ister macro until .. is encountered.
349 .ami macro end
350 Append to a macro indirectly. macro and end are string reg‐
351 isters whose contents are interpolated for the macro name and
352 the end macro, respectively.
353 .ami1 macro
354 Same as .ami but with compatibility mode switched off during
355 macro expansion.
356 .ami1 macro end
357 Same as .ami but with compatibility mode switched off during
358 macro expansion.
359 .as stringvar anything
360 Append anything to stringvar.
361 .as1 stringvar anything
362 Same as .as but with compatibility mode switched off during
363 string expansion.
364 .asciify diversion
365 Unformat ASCII characters, spaces, and some escape sequences
366 in diversion.
367 .backtrace
368 Print a backtrace of the input on stderr.
369 .bd font N
370 Embolden font by N-1 units.
371 .bd S font N
372 Embolden Special Font S when current font is font.
373 .blm Unset the blank line macro.
374 .blm macro
375 Set the blank line macro to macro.
376 .box End current diversion.
377 .box macro
378 Divert to macro, omitting a partially filled line.
379 .boxa End current diversion.
380 .boxa macro
381 Divert and append to macro, omitting a partially filled line.
382 .bp Eject current page and begin new page.
383 .bp ±N Eject current page; next page number ±N.
384 .br Line break.
385 .brp Break and spread output line. Same as \p.
386 .break Break out of a while loop.
387 .c2 Reset no-break control character to “'”.
388 .c2 c Set no-break control character to c.
389 .cc Reset control character to ‘.’.
390 .cc c Set control character to c.
391 .ce Center the next input line.
392 .ce N Center following N input lines.
393 .cf filename
394 Copy contents of file filename unprocessed to stdout or to
395 the diversion.
396 .cflags mode c1 c2 ...
397 Treat characters c1, c2, ... according to mode number.
398 .ch trap N
399 Change trap location to N.
400 .char c anything
401 Define entity c as string anything.
402 .chop object
403 Chop the last character off macro, string, or diversion
404 object.
405 .close stream
406 Close the stream.
407 .color Enable colors.
408 .color N If N is zero disable colors, otherwise enable them.
409 .composite from to
410 Map glyph name from to glyph name to while constructing a
411 composite glyph name.
412 .continue Finish the current iteration of a while loop.
413 .cp Enable compatibility mode.
414 .cp N If N is zero disable compatibility mode, otherwise enable it.
415 .cs font N M
416 Set constant character width mode for font to N/36 ems with
417 em M.
418 .cu N Continuous underline in nroff, like .ul in troff.
419 .da End current diversion.
420 .da macro Divert and append to macro.
421 .de macro Define or redefine macro until .. is encountered.
422 .de macro end
423 Define or redefine macro until .end is called.
424 .de1 macro
425 Same as .de but with compatibility mode switched off during
426 macro expansion.
427 .de1 macro end
428 Same as .de but with compatibility mode switched off during
429 macro expansion.
430 .defcolor color scheme component
431 Define or redefine a color with name color. scheme can be
432 rgb, cym, cymk, gray, or grey. component can be single com‐
433 ponents specified as fractions in the range 0 to 1 (default
434 scaling indicator f), as a string of two-digit hexadecimal
435 color components with a leading #, or as a string of four-
436 digit hexadecimal components with two leading #. The color
437 default can't be redefined.
438 .dei macro
439 Define or redefine a macro whose name is contained in the
440 string register macro until .. is encountered.
441 .dei macro end
442 Define or redefine a macro indirectly. macro and end are
443 string registers whose contents are interpolated for the
444 macro name and the end macro, respectively.
445 .dei1 macro
446 Same as .dei but with compatibility mode switched off during
447 macro expansion.
448 .dei1 macro end
449 Same as .dei but with compatibility mode switched off during
450 macro expansion.
451 .device anything
452 Write anything to the intermediate output as a device control
453 function.
454 .devicem name
455 Write contents of macro or string name uninterpreted to the
456 intermediate output as a device control function.
457 .di End current diversion.
458 .di macro Divert to macro.
459 .do name Interpret .name with compatibility mode disabled.
460 .ds stringvar anything
461 Set stringvar to anything.
462 .ds1 stringvar anything
463 Same as .ds but with compatibility mode switched off during
464 string expansion.
465 .dt N trap
466 Set diversion trap to position N (default scaling indica‐
467 tor v).
468 .ec Reset escape character to ‘\’.
469 .ec c Set escape character to c.
470 .ecr Restore escape character saved with .ecs.
471 .ecs Save current escape character.
472 .el anything
473 Else part for if-else (ie) request.
474 .em macro The macro is run after the end of input.
475 .eo Turn off escape character mechanism.
476 .ev Switch to previous environment and pop it off the stack.
477 .ev env Push down environment number or name env to the stack and
478 switch to it.
479 .evc env Copy the contents of environment env to the current environ‐
480 ment. No pushing or popping.
481 .ex Exit from roff processing.
482 .fam Return to previous font family.
483 .fam name Set the current font family to name.
484 .fc Disable field mechanism.
485 .fc a Set field delimiter to a and pad glyph to space.
486 .fc a b Set field delimiter to a and pad glyph to b.
487 .fchar c anything
488 Define fallback character (or glyph) c as string anything.
489 .fcolor Set fill color to previous fill color.
490 .fcolor c Set fill color to c.
491 .fi Fill output lines.
492 .fl Flush output buffer.
493 .fp n font
494 Mount font on position n.
495 .fp n internal external
496 Mount font with long external name to short internal name on
497 position n.
498 .fschar f c anything
499 Define fallback character (or glyph) c for font f as string
500 anything.
501 .fspecial font
502 Reset list of special fonts for font to be empty.
503 .fspecial font s1 s2 ...
504 When the current font is font, then the fonts s1, s2, ... are
505 special.
506 .ft Return to previous font. Same as \f[] or \fP.
507 .ft font Change to font name or number font; same as \f[font] escape
508 sequence.
509 .ftr font1 font2
510 Translate font1 to font2.
511 .fzoom font
512 Don't magnify font.
513 .fzoom font zoom
514 Set zoom factor for font (in multiples of 1/1000th).
515 .gcolor Set glyph color to previous glyph color.
516 .gcolor c Set glyph color to c.
517 .hc Remove additional hyphenation indicator character.
518 .hc c Set up additional hyphenation indicator character c.
519 .hcode c1 code1 c2 code2 ...
520 Set the hyphenation code of character c1 to code1, that of c2
521 to code2, etc.
522 .hla lang Set the current hyphenation language to lang.
523 .hlm n Set the maximum number of consecutive hyphenated lines to n.
524 .hpf file Read hyphenation patterns from file.
525 .hpfa file
526 Append hyphenation patterns from file.
527 .hpfcode a b c d ...
528 Set input mapping for .hpf.
529 .hw words List of words with exceptional hyphenation.
530 .hy N Switch to hyphenation mode N.
531 .hym n Set the hyphenation margin to n (default scaling indica‐
532 tor m).
533 .hys n Set the hyphenation space to n.
534 .ie cond anything
535 If cond then anything else goto .el.
536 .if cond anything
537 If cond then anything; otherwise do nothing.
538 .ig Ignore text until .. is encountered.
539 .ig end Ignore text until .end is called.
540 .in Change to previous indentation value.
541 .in ±N Change indentation according to ±N (default scaling indica‐
542 tor m).
543 .it N trap
544 Set an input-line count trap for the next N lines.
545 .itc N trap
546 Same as .it but count lines interrupted with \c as one line.
547 .kern Enable pairwise kerning.
548 .kern n If n is zero, disable pairwise kerning, otherwise enable it.
549 .lc Remove leader repetition glyph.
550 .lc c Set leader repetition glyph to c.
551 .length register anything
552 Write the length of the string anything to register.
553 .linetabs Enable line-tabs mode (i.e., calculate tab positions relative
554 to output line).
555 .linetabs n
556 If n is zero, disable line-tabs mode, otherwise enable it.
557 .lf N Set input line number to N.
558 .lf N file
559 Set input line number to N and filename to file.
560 .lg N Ligature mode on if N>0.
561 .ll Change to previous line length.
562 .ll ±N Set line length according to ±N (default length 6.5i, default
563 scaling indicator m).
564 .ls Change to the previous value of additional intra-line skip.
565 .ls N Set additional intra-line skip value to N, i.e., N-1 blank
566 lines are inserted after each text output line.
567 .lt ±N Length of title (default scaling indicator m).
568 .mc Margin glyph off.
569 .mc c Print glyph c after each text line at actual distance from
570 right margin.
571 .mc c N Set margin glyph to c and distance to N from right margin
572 (default scaling indicator m).
573 .mk register
574 Mark current vertical position in register.
575 .mso file The same as .so except that file is searched in the tmac
576 directories.
577 .na No output-line adjusting.
578 .ne Need a one-line vertical space.
579 .ne N Need N vertical space (default scaling indicator v).
580 .nf No filling or adjusting of output-lines.
581 .nh No hyphenation.
582 .nm Number mode off.
583 .nm ±N [M [S [I]]]
584 In line number mode, set number, multiple, spacing, and
585 indentation.
586 .nn Do not number next line.
587 .nn N Do not number next N lines.
588 .nop anything
589 Always process anything.
590 .nr register ±N [M]
591 Define or modify register using ±N with auto-increment M.
592 .nroff Make the built-in conditions n true and t false.
593 .ns Turn on no-space mode.
594 .nx Immediately jump to end of current file.
595 .nx filename
596 Immediately continue processing with file file.
597 .open stream filename
598 Open filename for writing and associate the stream named
599 stream with it.
600 .opena stream filename
601 Like .open but append to it.
602 .os Output vertical distance that was saved by the sv request.
603 .output string
604 Emit string directly to intermediate output, allowing leading
605 whitespace if string starts with " (which is stripped off).
606 .pc Reset page number character to ‘%’.
607 .pc c Page number character.
608 .pev Print the current environment and each defined environment
609 state to stderr.
610 .pi program
611 Pipe output to program (nroff only).
612 .pl Set page length to default 11i. The current page length is
613 stored in register .p.
614 .pl ±N Change page length to ±N (default scaling indicator v).
615 .pm Print macro names and sizes (number of blocks of 128 bytes).
616 .pm t Print only total of sizes of macros (number of 128 bytes
617 blocks).
618 .pn ±N Next page number N.
619 .pnr Print the names and contents of all currently defined number
620 registers on stderr.
621 .po Change to previous page offset. The current page offset is
622 available in register .o.
623 .po ±N Page offset N.
624 .ps Return to previous point size.
625 .ps ±N Point size; same as \s[±N].
626 .psbb filename
627 Get the bounding box of a PostScript image filename.
628 .pso command
629 This behaves like the so request except that input comes from
630 the standard output of command.
631 .ptr Print the names and positions of all traps (not including
632 input line traps and diversion traps) on stderr.
633 .pvs Change to previous post-vertical line spacing.
634 .pvs ±N Change post-vertical line spacing according to ±N (default
635 scaling indicator p).
636 .rchar c1 c2 ...
637 Remove the definitions of entities c1, c2, ...
638 .rd prompt
639 Read insertion.
640 .return Return from a macro.
641 .return anything
642 Return twice, namely from the macro at the current level and
643 from the macro one level higher.
644 .rfschar f c1 c2 ...
645 Remove the definitions of entities c1, c2, ... for font f.
646 .rj n Right justify the next n input lines.
647 .rm name Remove request, macro, or string name.
648 .rn old new
649 Rename request, macro, or string old to new.
650 .rnn reg1 reg2
651 Rename register reg1 to reg2.
652 .rr register
653 Remove register.
654 .rs Restore spacing; turn no-space mode off.
655 .rt ±N Return (upward only) to marked vertical place (default scal‐
656 ing indicator v).
657 .schar c anything
658 Define global fallback character (or glyph) c as string any‐
659 thing.
660 .shc Reset soft hyphen glyph to \(hy.
661 .shc c Set the soft hyphen glyph to c.
662 .shift n In a macro, shift the arguments by n positions.
663 .sizes s1 s2 ... sn [0]
664 Set available font sizes similar to the sizes command in a
665 DESC file.
666 .so filename
667 Include source file.
668 .sp Skip one line vertically.
669 .sp N Space vertical distance N up or down according to sign of N
670 (default scaling indicator v).
671 .special Reset global list of special fonts to be empty.
672 .special s1 s2 ...
673 Fonts s1, s2, etc. are special and are searched for glyphs
674 not in the current font.
675 .spreadwarn
676 Toggle the spread warning on and off without changing its
677 value.
678 .spreadwarn limit
679 Emit a warning if each space in an output line is widened by
680 limit or more (default scaling indicator m).
681 .ss N Set space glyph size to N/12 of the space width in the cur‐
682 rent font.
683 .ss N M Set space glyph size to N/12 and sentence space size set to
684 M/12 of the space width in the current font.
685 .sty n style
686 Associate style with font position n.
687 .substring xx n1 n2
688 Replace the string named xx with the substring defined by the
689 indices n1 and n2.
690 .sv Save 1 v of vertical space.
691 .sv N Save the vertical distance N for later output with os request
692 (default scaling indicator v).
693 .sy command-line
694 Execute program command-line.
695 .ta T N Set tabs after every position that is a multiple of N
696 (default scaling indicator m).
697 .ta n1 n2 ... nn T r1 r2 ... rn
698 Set tabs at positions n1, n2, ..., nn, then set tabs at
699 nn+r1, nn+r2, ..., nn+rn, then at nn+rn+r1, nn+rn+r2, ...,
700 nn+rn+rn, and so on.
701 .tc Remove tab repetition glyph.
702 .tc c Set tab repetition glyph to c.
703 .ti ±N Temporary indent next line (default scaling indicator m).
704 .tkf font s1 n1 s2 n2
705 Enable track kerning for font.
706 .tl ’left’center’right’
707 Three-part title.
708 .tm anything
709 Print anything on stdout.
710 .tm1 anything
711 Print anything on stdout, allowing leading whitespace if any‐
712 thing starts with " (which is stripped off).
713 .tmc anything
714 Similar to .tm1 without emitting a final newline.
715 .tr abcd...
716 Translate a to b, c to d, etc. on output.
717 .trf filename
718 Transparently output the contents of file filename.
719 .trin abcd...
720 This is the same as the tr request except that the asciify
721 request uses the character code (if any) before the character
722 translation.
723 .trnt abcd...
724 This is the same as the tr request except that the transla‐
725 tions do not apply to text that is transparently throughput
726 into a diversion with \!.
727 .troff Make the built-in conditions t true and n false.
728 .uf font Set underline font to font (to be switched to by .ul).
729 .ul N Underline (italicize in troff) N input lines.
730 .unformat diversion
731 Unformat space characters and tabs in diversion, preserving
732 font information.
733 .vpt n Enable vertical position traps if n is non-zero, disable them
734 otherwise.
735 .vs Change to previous vertical base line spacing.
736 .vs ±N Set vertical base line spacing to ±N (default scaling indica‐
737 tor p).
738 .warn n Set warnings code to n.
739 .warnscale si
740 Set scaling indicator used in warnings to si.
741 .wh N Remove (first) trap at position N.
742 .wh N trap
743 Set location trap; negative means from page bottom.
744 .while cond anything
745 While condition cond is true, accept anything as input.
746 .write stream anything
747 Write anything to the stream named stream.
748 .writec stream anything
749 Similar to .write without emitting a final newline.
750 .writem stream xx
751 Write contents of macro or string xx to the stream named
752 stream.
753 Besides these standard groff requests, there might be further macro
755 calls. They can originate from a macro package (see roff(7) for an
756 overview) or from a preprocessor.
757 Preprocessor macros are easy to be recognized. They enclose their code
759 into a pair of characteristic macros.
760 ┌─────────────┬─────────────┬────────────┐
762 │preprocessor │ start macro │ end macro │
763 ├─────────────┼─────────────┼────────────┤
764 │ eqn │ .EQ │ .EN │
765 │ grap │ .G1 │ .G2 │
766 │ grn │ .GS │ .GE │
767 │ pic │ .PS │ .PE │
768 │ refer │ .R1 │ .R2 │
769 │ soelim │ none │ none │
770 │ tbl │ .TS │ .TE │
771 └─────────────┴─────────────┴────────────┘
773 Escape sequences are in-line language elements usually introduced by a
774 backslash ‘\’ and followed by an escape name and sometimes by a
775 required argument. Input processing is continued directly after the
776 escaped character or the argument (without an intervening separation
777 character). So there must be a way to determine the end of the escape
778 name and the end of the argument.
779 This is done by enclosing names (escape name and arguments consisting
781 of a variable name) by a pair of brackets [name] and constant arguments
782 (number expressions and characters) by apostrophes (ASCII 0x27) like
783 ’constant’.
784 There are abbreviations for short names. Two-character escape names
786 can be specified by an opening parenthesis like \(xy or \*(xy without a
787 closing counterpart. And all one-character names different from the
788 special characters ‘[’ and ‘(’ can even be specified without a marker,
789 for example \nc or \$c.
790 Constant arguments of length 1 can omit the marker apostrophes, too,
792 but there is no two-character analogue.
793 While one-character escape sequences are mainly used for in-line func‐
795 tions and system related tasks, the two-letter names following the \(
796 construct are glyphs predefined by the roff system; these are called
797 `Special Characters' in the classical documentation. Escapes sequences
798 of the form \[name] denote glyphs too.
799 Single-Character Escapes
801 \" Start of a comment. Everything up to the end of the line is
802 ignored.
803 \# Everything up to and including the next newline is ignored.
804 This is interpreted in copy mode. This is like \" except that
805 the terminating newline is ignored as well.
806 \*s The string stored in the string variable with one-character
807 name s.
808 \*(st The string stored in the string variable with two-character name
809 st.
810 \*[string]
811 The string stored in the string variable with name string (with
812 arbitrary length).
813 \*[stringvar arg1 arg2 ...]
814 The string stored in the string variable with arbitrarily long
815 name stringvar, taking arg1, arg2, ... as arguments.
816 \$0 The name by which the current macro was invoked. The als
817 request can make a macro have more than one name.
818 \$x Macro or string argument with one-digit number x in the range 1
819 to 9.
820 \$(xy Macro or string argument with two-digit number xy (larger than
821 zero).
822 \$[nexp]
823 Macro or string argument with number nexp, where nexp is a
824 numerical expression evaluating to an integer ≥1.
825 \$* In a macro or string, the concatenation of all the arguments
826 separated by spaces.
827 \$@ In a macro or string, the concatenation of all the arguments
828 with each surrounded by double quotes, and separated by spaces.
829 \$^ In a macro, the representation of all parameters as if they were
830 an argument to the ds request.
831 \\ reduces to a single backslash; useful to delay its interpreta‐
832 tion as escape character in copy mode. For a printable back‐
833 slash, use \e, or even better \[rs], to be independent from the
834 current escape character.
835 \’ The acute accent ´; same as \(aa. Unescaped: apostrophe, right
836 quotation mark, single quote (ASCII 0x27).
837 \` The grave accent `; same as \(ga. Unescaped: left quote, back‐
838 quote (ASCII 0x60).
839 \- The - (minus) sign in the current font.
840 \_ The same as \(ul, the underline character.
841 \. An uninterpreted dot (period), even at start of line.
842 \% Default optional hyphenation character.
843 \! Transparent line indicator.
844 \?anything?
845 In a diversion, this transparently embeds anything in the diver‐
846 sion. anything is read in copy mode. See also the escape
847 sequences \! and \?.
848 \space Unpaddable space size space glyph (no line break).
849 \0 Digit-width space.
850 \| 1/6 em narrow space glyph; zero width in nroff.
851 \^ 1/12 em half-narrow space glyph; zero width in nroff.
852 \& Non-printable, zero-width glyph.
853 \) Like \& except that it behaves like a glyph declared with the
854 cflags request to be transparent for the purposes of end-of-sen‐
855 tence recognition.
856 \/ Increases the width of the preceding glyph so that the spacing
857 between that glyph and the following glyph is correct if the
858 following glyph is a roman glyph.
859 \, Modifies the spacing of the following glyph so that the spacing
860 between that glyph and the preceding glyph is correct if the
861 preceding glyph is a roman glyph.
862 \~ Unbreakable space that stretches like a normal inter-word space
863 when a line is adjusted.
864 \: Inserts a zero-width break point (similar to \% but without a
865 soft hyphen character).
866 \newline
867 Ignored newline, for continuation lines.
868 \{ Begin conditional input.
869 \} End conditional input.
870 \(sc A glyph with two-character name sc; see section Special Charac‐
871 ters.
872 \[name]
873 A glyph with name name (of arbitrary length).
874 \[comp1 comp2 ...]
875 A composite glyph with components comp1, comp2, ...
876 \a Non-interpreted leader character.
877 \A’anything’
878 If anything is acceptable as a name of a string, macro, diver‐
879 sion, register, environment or font it expands to 1, and to 0
880 otherwise.
881 \b’abc...’
882 Bracket building function.
883 \B’anything’
884 If anything is acceptable as a valid numeric expression it
885 expands to 1, and to 0 otherwise.
886 \c Interrupt text processing.
887 \C’glyph’
888 The glyph called glyph; same as \[glyph], but compatible to
889 other roff versions.
890 \d Forward (down) 1/2 em (1/2 line in nroff).
891 \D’charseq’
892 Draw a graphical element defined by the characters in charseq;
893 see the groff info file for details.
894 \e Printable version of the current escape character.
895 \E Equivalent to an escape character, but is not interpreted in
896 copy mode.
897 \fF Change to font with one-character name or one-digit number F.
898 \fP Switch back to previous font.
899 \f(fo Change to font with two-character name or two-digit number fo.
900 \f[font]
901 Change to font with arbitrarily long name or number expression
902 font.
903 \f[] Switch back to previous font.
904 \Ff Change to font family with one-character name f.
905 \F(fm Change to font family with two-character name fm.
906 \F[fam]
907 Change to font family with arbitrarily long name fam.
908 \F[] Switch back to previous font family.
909 \gr Return format of register with one-character name r suitable for
910 af request.
911 \g(rg Return format of register with two-character name rg suitable
912 for af request.
913 \g[reg]
914 Return format of register with arbitrarily long name reg suit‐
915 able for af request.
916 \h’N’ Local horizontal motion; move right N (left if negative).
917 \H’N’ Set height of current font to N.
918 \kr Mark horizontal input place in one-character register r.
919 \k(rg Mark horizontal input place in two-character register rg.
920 \k[reg]
921 Mark horizontal input place in register with arbitrarily long
922 name reg.
923 \l’Nc’ Horizontal line drawing function (optionally using character c).
924 \L’Nc’ Vertical line drawing function (optionally using character c).
925 \mc Change to color with one-character name c.
926 \m(cl Change to color with two-character name cl.
927 \m[color]
928 Change to color with arbitrarily long name color.
929 \m[] Switch back to previous color.
930 \Mc Change filling color for closed drawn objects to color with one-
931 character name c.
932 \M(cl Change filling color for closed drawn objects to color with two-
933 character name cl.
934 \M[color]
935 Change filling color for closed drawn objects to color with
936 arbitrarily long name color.
937 \M[] Switch to previous fill color.
938 \nr The numerical value stored in the register variable with the
939 one-character name r.
940 \n(re The numerical value stored in the register variable with the
941 two-character name re.
942 \n[reg]
943 The numerical value stored in the register variable with arbi‐
944 trarily long name reg.
945 \N’n’ Typeset the glyph with index n in the current font. No special
946 fonts are searched. Useful for adding (named) entities to a
947 document using the char request and friends.
948 \o’abc...’
949 Overstrike glyphs a, b, c, etc.
950 \O0 Disable glyph output. Mainly for internal use.
951 \O1 Enable glyph output. Mainly for internal use.
952 \p Break and spread output line.
953 \r Reverse 1 em vertical motion (reverse line in nroff).
954 \R’name ±n’
955 The same as .nr name ±n.
956 \s±N Set/increase/decrease the point size to/by N scaled points; N is
957 a one-digit number in the range 1 to 9. Same as ps request.
958 \s(±N
959 \s±(N Set/increase/decrease the point size to/by N scaled points; N is
960 a two-digit number ≥1. Same as ps request.
961 \s[±N]
962 \s±[N]
963 \s’±N’
964 \s±’N’ Set/increase/decrease the point size to/by N scaled points.
965 Same as ps request.
966 \S’N’ Slant output by N degrees.
967 \t Non-interpreted horizontal tab.
968 \u Reverse (up) 1/2 em vertical motion (1/2 line in nroff).
969 \v’N’ Local vertical motion; move down N (up if negative).
970 \Ve The contents of the environment variable with one-character
971 name e.
972 \V(ev The contents of the environment variable with two-character name
973 ev.
974 \V[env]
975 The contents of the environment variable with arbitrarily long
976 name env.
977 \w’string’
978 The width of the glyph sequence string.
979 \x’N’ Extra line-space function (negative before, positive after).
980 \X’string’
981 Output string as device control function.
982 \Yn Output string variable or macro with one-character name n unin‐
983 terpreted as device control function.
984 \Y(nm Output string variable or macro with two-character name nm unin‐
985 terpreted as device control function.
986 \Y[name]
987 Output string variable or macro with arbitrarily long name name
988 uninterpreted as device control function.
989 \zc Print c with zero width (without spacing).
990 \Z’anything’
991 Print anything and then restore the horizontal and vertical
992 position; anything may not contain tabs or leaders.
993 The escape sequences \e, \., \", \$, \*, \a, \n, \t, \g, and \newline
995 are interpreted in copy mode.
996 Escape sequences starting with \( or \[ do not represent single charac‐
998 ter escape sequences, but introduce escape names with two or more char‐
999 acters.
1000 If a backslash is followed by a character that does not constitute a
1002 defined escape sequence, the backslash is silently ignored and the
1003 character maps to itself.
1004 Special Characters
1006 [Note: `Special Characters' is a misnomer; those entities are (output)
1007 glyphs, not (input) characters.]
1008 Common special characters are predefined by escape sequences of the
1010 form \(xy with characters x and y. Some of these exist in the usual
1011 font while most of them are only available in the special font. Below
1012 you can find a selection of the most important glyphs; a complete list
1013 can be found in groff_char(7).
1014 \(bu Bullet sign
1016 \(co Copyright
1017 \(ct Cent
1018 \(dd Double dagger
1019 \(de Degree
1020 \(dg Dagger
1021 \(rq Printable double quote
1022 \(em Em-dash
1023 \(hy Hyphen
1024 \(rg Registered sign
1025 \(rs Printable backslash character
1026 \(sc Section sign
1027 \(ul Underline character
1028 \(== Identical
1029 \(>= Larger or equal
1030 \(<= Less or equal
1031 \(!= Not equal
1032 \(-> Right arrow
1033 \(<- Left arrow
1034 \(+- Plus-minus sign
1035 Strings
1037 Strings are defined by the ds request and can be retrieved by the \*
1038 escape sequence.
1039 Strings share their name space with macros. So strings and macros
1041 without arguments are roughly equivalent; it is possible to call a
1042 string like a macro and vice-versa, but this often leads to unpre‐
1043 dictable results. The following string is the only one predefined in
1044 groff.
1045 \*[.T] The name of the current output device as specified by the -T
1047 command line option.
1048
1050 Registers are variables that store a value. In groff, most registers
1051 store numerical values (see section NUMERICAL EXPRESSIONS above), but
1052 some can also hold a string value.
1053 Each register is given a name. Arbitrary registers can be defined and
1055 set with the nr request.
1056 The value stored in a register can be retrieved by the escape sequences
1058 introduced by \n.
1059 Most useful are predefined registers. In the following the notation
1061 name is used to refer to register name to make clear that we speak
1062 about registers. Please keep in mind that the \n[] decoration is not
1063 part of the register name.
1064 Read-only Registers
1066 The following registers have predefined values that should not be modi‐
1067 fied by the user (usually, registers starting with a dot a read-only).
1068 Mostly, they provide information on the current settings or store
1069 results from request calls.
1070 \n[.$] Number of arguments in the current macro or string.
1072 \n[.a] Post-line extra line-space most recently utilized using \x.
1073 \n[.A] Set to 1 in troff if option -A is used; always 1 in nroff.
1074 \n[.br] Within a macro, set to 1 if macro called with the `normal'
1075 control character, and to 0 otherwise.
1076 \n[.c] Current input line number.
1077 \n[.C] 1 if compatibility mode is in effect, 0 otherwise.
1078 \n[.cdp] The depth of the last glyph added to the current environment.
1079 It is positive if the glyph extends below the baseline.
1080 \n[.ce] The number of lines remaining to be centered, as set by the
1081 ce request.
1082 \n[.cht] The height of the last glyph added to the current environ‐
1083 ment. It is positive if the glyph extends above the base‐
1084 line.
1085 \n[.color]
1086 1 if colors are enabled, 0 otherwise.
1087 \n[.csk] The skew of the last glyph added to the current environment.
1088 The skew of a glyph is how far to the right of the center of
1089 a glyph the center of an accent over that glyph should be
1090 placed.
1091 \n[.d] Current vertical place in current diversion; equal to regis‐
1092 ter nl.
1093 \n[.ev] The name or number of the current environment (string-val‐
1094 ued).
1095 \n[.f] Current font number.
1096 \n[.fam] The current font family (string-valued).
1097 \n[.fn] The current (internal) real font name (string-valued).
1098 \n[.fp] The number of the next free font position.
1099 \n[.g] Always 1 in GNU troff. Macros should use it to test if run‐
1100 ning under groff.
1101 \n[.h] Text base-line high-water mark on current page or diversion.
1102 \n[.H] Available horizontal resolution in basic units.
1103 \n[.height]
1104 The current font height as set with \H.
1105 \n[.hla] The current hyphenation language as set by the hla request.
1106 \n[.hlc] The number of immediately preceding consecutive hyphenated
1107 lines.
1108 \n[.hlm] The maximum allowed number of consecutive hyphenated lines,
1109 as set by the hlm request.
1110 \n[.hy] The current hyphenation flags (as set by the hy request).
1111 \n[.hym] The current hyphenation margin (as set by the hym request).
1112 \n[.hys] The current hyphenation space (as set by the hys request).
1113 \n[.i] Current indentation.
1114 \n[.in] The indentation that applies to the current output line.
1115 \n[.int] Positive if last output line contains \c.
1116 \n[.kern] 1 if pairwise kerning is enabled, 0 otherwise.
1117 \n[.l] Current line length.
1118 \n[.lg] The current ligature mode (as set by the lg request).
1119 \n[.linetabs]
1120 The current line-tabs mode (as set by the linetabs request).
1121 \n[.ll] The line length that applies to the current output line.
1122 \n[.lt] The title length (as set by the lt request).
1123 \n[.m] The current drawing color (string-valued).
1124 \n[.M] The current background color (string-valued).
1125 \n[.n] Length of text portion on previous output line.
1126 \n[.ne] The amount of space that was needed in the last ne request
1127 that caused a trap to be sprung. Useful in conjunction with
1128 register .trunc.
1129 \n[.ns] 1 if in no-space mode, 0 otherwise.
1130 \n[.o] Current page offset.
1131 \n[.p] Current page length.
1132 \n[.pe] 1 during page ejection, 0 otherwise.
1133 \n[.pn] The number of the next page: either the value set by a pn
1134 request, or the number of the current page plus 1.
1135 \n[.ps] The current point size in scaled points.
1136 \n[.psr] The last-requested point size in scaled points.
1137 \n[.pvs] The current post-vertical line spacing.
1138 \n[.rj] The number of lines to be right-justified as set by the rj
1139 request.
1140 \n[.s] Current point size as a decimal fraction.
1141 \n[.slant]
1142 The slant of the current font as set with \S.
1143 \n[.sr] The last requested point size in points as a decimal fraction
1144 (string-valued).
1145 \n[.ss] The value of the parameters set by the first argument of the
1146 ss request.
1147 \n[.sss] The value of the parameters set by the second argument of the
1148 ss request.
1149 \n[.sty] The current font style (string-valued).
1150 \n[.t] Vertical distance to the next trap.
1151 \n[.T] Set to 1 if option -T is used.
1152 \n[.tabs] A string representation of the current tab settings suitable
1153 for use as an argument to the ta request.
1154 \n[.trunc]
1155 The amount of vertical space truncated by the most recently
1156 sprung vertical position trap, or, if the trap was sprung by
1157 a ne request, minus the amount of vertical motion produced by
1158 .ne. Useful in conjunction with the register .ne.
1159 \n[.u] Equal to 1 in fill mode and 0 in no-fill mode.
1160 \n[.U] Equal to 1 in safer mode and 0 in unsafe mode.
1161 \n[.v] Current vertical line spacing.
1162 \n[.V] Available vertical resolution in basic units.
1163 \n[.vpt] 1 if vertical position traps are enabled, 0 otherwise.
1164 \n[.w] Width of previous glyph.
1165 \n[.warn] The sum of the number codes of the currently enabled warn‐
1166 ings.
1167 \n[.x] The major version number.
1168 \n[.y] The minor version number.
1169 \n[.Y] The revision number of groff.
1170 \n[.z] Name of current diversion.
1171 \n[.zoom] Zoom factor for current font (in multiples of 1/1000th; zero
1172 if no magnification).
1173 Writable Registers
1175 The following registers can be read and written by the user. They have
1176 predefined default values, but these can be modified for customizing a
1177 document.
1178 \n[%] Current page number.
1180 \n[c.] Current input line number.
1181 \n[ct] Character type (set by width function \w).
1182 \n[dl] Maximal width of last completed diversion.
1183 \n[dn] Height of last completed diversion.
1184 \n[dw] Current day of week (1-7).
1185 \n[dy] Current day of month (1-31).
1186 \n[hours] The number of hours past midnight. Initialized at start-up.
1187 \n[hp] Current horizontal position at input line.
1188 \n[llx] Lower left x-coordinate (in PostScript units) of a given
1189 PostScript image (set by .psbb).
1190 \n[lly] Lower left y-coordinate (in PostScript units) of a given
1191 PostScript image (set by .psbb).
1192 \n[ln] Output line number.
1193 \n[minutes]
1194 The number of minutes after the hour. Initialized at start-
1195 up.
1196 \n[mo] Current month (1-12).
1197 \n[nl] Vertical position of last printed text base-line.
1198 \n[rsb] Like register sb, but takes account of the heights and depths
1199 of glyphs.
1200 \n[rst] Like register st, but takes account of the heights and depths
1201 of glyphs.
1202 \n[sb] Depth of string below base line (generated by width function
1203 \w).
1204 \n[seconds]
1205 The number of seconds after the minute. Initialized at
1206 start-up.
1207 \n[skw] Right skip width from the center of the last glyph in the \w
1208 argument.
1209 \n[slimit]
1210 If greater than 0, the maximum number of objects on the input
1211 stack. If ≤0 there is no limit, i.e., recursion can continue
1212 until virtual memory is exhausted.
1213 \n[ssc] The amount of horizontal space (possibly negative) that
1214 should be added to the last glyph before a subscript (gener‐
1215 ated by width function \w).
1216 \n[st] Height of string above base line (generated by width function
1217 \w).
1218 \n[systat]
1219 The return value of the system() function executed by the
1220 last sy request.
1221 \n[urx] Upper right x-coordinate (in PostScript units) of a given
1222 PostScript image (set by .psbb).
1223 \n[ury] Upper right y-coordinate (in PostScript units) of a given
1224 PostScript image (set by .psbb).
1225 \n[year] The current year (year 2000 compliant).
1226 \n[yr] Current year minus 1900. For Y2K compliance use register
1227 year instead.
1228
1230 The differences of the groff language in comparison to classical troff
1231 as defined by [CSTR #54] are documented in groff_diff(7).
1232 The groff system provides a compatibility mode, see groff(1) on how to
1234 invoke this.
1235
1237 Report bugs to the groff bug mailing list ⟨bug-groff@gnu.org⟩. Include
1238 a complete, self-contained example that will allow the bug to be repro‐
1239 duced, and say which version of groff you are using.
1240
1242 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
1243 2009 Free Software Foundation, Inc.
1244 This document is distributed under the terms of the FDL (GNU Free Docu‐
1246 mentation License) version 1.3 or later. You should have received a
1247 copy of the FDL on your system, it is also available on-line at the GNU
1248 copyleft site ⟨http://www.gnu.org/copyleft/fdl.html⟩.
1249 This document is part of groff, the GNU roff distribution. It was
1251 written by Bernd Warken ⟨bwarken@mayn.de⟩; it is maintained by Werner
1252 Lemberg ⟨wl@gnu.org⟩.
1253
1255 The main source of information for the groff language is the groff
1256 info(1) file. Besides the gory details, it contains many examples.
1257 groff(1)
1259 the usage of the groff program and pointers to the documentation
1260 and availability of the groff system.
1261 groff_diff(7)
1263 the differences of the groff language as compared to classical
1264 roff. This is the authoritative document for the predefined
1265 language elements that are specific to groff.
1266 groff_char(7)
1268 the predefined groff special characters (glyphs).
1269 groff_font(5)
1271 the specification of fonts and the DESC file.
1272 roff(7)
1274 the history of roff, the common parts shared by all roff sys‐
1275 tems, and pointers to further documentation.
1276 [CSTR #54]
1278 Nroff/Troff User's Manual by Ossanna & Kernighan ⟨http://
1279 cm.bell-labs.com/cm/cs/cstr/54.ps.gz⟩ — the bible for classical
1280 troff.
1281Groff Version 1.20.1 9 January 2009 GROFF(7)