1MDOC.SAMPLES(7) BSD Miscellaneous Information Manual MDOC.SAMPLES(7)
2
4 mdoc.samples — tutorial sampler for writing BSD manuals with -mdoc
5
7 man mdoc.samples
8
10 A tutorial sampler for writing BSD manual pages with the -mdoc macro
11 package, a content-based and domain-based formatting package for
12 troff(1). Its predecessor, the -man(7) package, addressed page layout
13 leaving the manipulation of fonts and other typesetting details to the
14 individual author. In -mdoc, page layout macros make up the page
15 structure domain which consists of macros for titles, section headers,
16 displays and lists. Essentially items which affect the physical position
17 of text on a formatted page. In addition to the page structure domain,
18 there are two more domains, the manual domain and the general text
19 domain. The general text domain is defined as macros which perform tasks
20 such as quoting or emphasizing pieces of text. The manual domain is
21 defined as macros that are a subset of the day to day informal language
22 used to describe commands, routines and related BSD files. Macros in the
23 manual domain handle command names, command-line arguments and options,
24 function names, function parameters, pathnames, variables, cross refer‐
25 ences to other manual pages, and so on. These domain items have value
26 for both the author and the future user of the manual page. It is hoped
27 the consistency gained across the manual set will provide easier transla‐
28 tion to future documentation tools.
29
30 Throughout the UNIX manual pages, a manual entry is simply referred to as
31 a man page, regardless of actual length and without sexist intention.
32
34 Since a tutorial document is normally read when a person desires to use
35 the material immediately, the assumption has been made that the user of
36 this document may be impatient. The material presented in the remained
37 of this document is outlined as follows:
38
39 1. TROFF IDIOSYNCRASIES
40 Macro Usage.
41 Passing Space Characters in an Argument.
42 Trailing Blank Space Characters (a warning).
43 Escaping Special Characters.
44
45 2. THE ANATOMY OF A MAN PAGE
46 A manual page template.
47
48 3. TITLE MACROS.
49
50 4. INTRODUCTION OF MANUAL AND GENERAL TEXT DOMAINS.
51 What's in a name....
52 General Syntax.
53
54 5. MANUAL DOMAIN
55 Addresses.
56 Author name.
57 Arguments.
58 Configuration Declarations (section four only).
59 Command Modifier.
60 Defined Variables.
61 Errno's (Section two only).
62 Environment Variables.
63 Function Argument.
64 Function Declaration.
65 Flags.
66 Functions (library routines).
67 Function Types.
68 Interactive Commands.
69 Names.
70 Options.
71 Pathnames.
72 Variables.
73 Cross References.
74
75 6. GENERAL TEXT DOMAIN
76 AT&T Macro.
77 BSD Macro.
78 FreeBSD Macro.
79 UNIX Macro.
80 Enclosure/Quoting Macros
81 Angle Bracket Quote/Enclosure.
82 Bracket Quotes/Enclosure.
83 Double Quote macro/Enclosure.
84 Parenthesis Quote/Enclosure.
85 Single Quotes/Enclosure.
86 Prefix Macro.
87 No-Op or Normal Text Macro.
88 No Space Macro.
89 Section Cross References.
90 References and Citations.
91 Return Values (sections two and three only)
92 Trade Names (Acronyms and Type Names).
93 Extended Arguments.
94
95 7. PAGE STRUCTURE DOMAIN
96 Section Headers.
97 Paragraphs and Line Spacing.
98 Keeps.
99 Displays.
100 Font Modes (Emphasis, Literal, and Symbolic).
101 Lists and Columns.
102
103 8. PREDEFINED STRINGS
104
105 9. DIAGNOSTICS
106
107 10. FORMATTING WITH GROFF, TROFF AND NROFF
108
109 11. BUGS
110
112 The -mdoc package attempts to simplify the process of writing a man page.
113 Theoretically, one should not have to learn the dirty details of troff(1)
114 to use -mdoc; however, there are a few limitations which are unavoidable
115 and best gotten out of the way. And, too, be forewarned, this package is
116 not fast.
117
118 Macro Usage
119 As in troff(1), a macro is called by placing a ‘.’ (dot character) at the
120 beginning of a line followed by the two character name for the macro.
121 Arguments may follow the macro separated by spaces. It is the dot char‐
122 acter at the beginning of the line which causes troff(1) to interpret the
123 next two characters as a macro name. To place a ‘.’ (dot character) at
124 the beginning of a line in some context other than a macro invocation,
125 precede the ‘.’ (dot) with the ‘\&’ escape sequence. The ‘\&’ translates
126 literally to a zero width space, and is never displayed in the output.
127
128 In general, troff(1) macros accept up to nine arguments, any extra argu‐
129 ments are ignored. Most macros in -mdoc accept nine arguments and, in
130 limited cases, arguments may be continued or extended on the next line
131 (See Extensions). A few macros handle quoted arguments (see Passing
132 Space Characters in an Argument below).
133
134 Most of the -mdoc general text domain and manual domain macros are spe‐
135 cial in that their argument lists are parsed for callable macro names.
136 This means an argument on the argument list which matches a general text
137 or manual domain macro name and is determined to be callable will be exe‐
138 cuted or called when it is processed. In this case the argument,
139 although the name of a macro, is not preceded by a ‘.’ (dot). It is in
140 this manner that many macros are nested; for example the option macro,
141 ‘.Op’, may call the flag and argument macros, ‘Fl’ and ‘Ar’, to specify
142 an optional flag with an argument:
143
144 [-s bytes] is produced by .Op Fl s Ar bytes
145
146 To prevent a two character string from being interpreted as a macro name,
147 precede the string with the escape sequence ‘\&’:
148
149 [Fl s Ar bytes] is produced by .Op \&Fl s \&Ar bytes
150
151 Here the strings ‘Fl’ and ‘Ar’ are not interpreted as macros. Macros
152 whose argument lists are parsed for callable arguments are referred to as
153 parsed and macros which may be called from an argument list are referred
154 to as callable throughout this document and in the companion quick refer‐
155 ence manual mdoc(7). This is a technical faux pas as almost all of the
156 macros in -mdoc are parsed, but as it was cumbersome to constantly refer
157 to macros as being callable and being able to call other macros, the term
158 parsed has been used.
159
160 Passing Space Characters in an Argument
161 Sometimes it is desirable to give as one argument a string containing one
162 or more blank space characters. This may be necessary to defeat the nine
163 argument limit or to specify arguments to macros which expect particular
164 arrangement of items in the argument list. For example, the function
165 macro ‘.Fn’ expects the first argument to be the name of a function and
166 any remaining arguments to be function parameters. As ANSI C stipulates
167 the declaration of function parameters in the parenthesized parameter
168 list, each parameter is guaranteed to be at minimum a two word string.
169 For example, int foo.
170
171 There are two possible ways to pass an argument which contains an embed‐
172 ded space. Implementation note: Unfortunately, the most convenient way
173 of passing spaces in between quotes by reassigning individual arguments
174 before parsing was fairly expensive speed wise and space wise to imple‐
175 ment in all the macros for AT&T troff. It is not expensive for groff but
176 for the sake of portability, has been limited to the following macros
177 which need it the most:
178
179 Cd Configuration declaration (section 4 SYNOPSIS)
180 Bl Begin list (for the width specifier).
181 Em Emphasized text.
182 Fn Functions (sections two and four).
183 It List items.
184 Li Literal text.
185 Sy Symbolic text.
186 %B Book titles.
187 %J Journal names.
188 %O Optional notes for a reference.
189 %R Report title (in a reference).
190 %T Title of article in a book or journal.
191
192 One way of passing a string containing blank spaces is to use the hard or
193 unpaddable space character ‘\ ’, that is, a blank space preceded by the
194 escape character ‘\’. This method may be used with any macro but has the
195 side effect of interfering with the adjustment of text over the length of
196 a line. Troff sees the hard space as if it were any other printable
197 character and cannot split the string into blank or newline separated
198 pieces as one would expect. The method is useful for strings which are
199 not expected to overlap a line boundary. For example:
200
201 fetch(char *str) is created by ‘.Fn fetch char\ *str’
202
203 fetch(char *str) can also be created by ‘.Fn fetch "char *str"’
204
205 If the ‘\’ or quotes were omitted, ‘.Fn’ would see three arguments and
206 the result would be:
207
208 fetch(char, *str)
209
210 For an example of what happens when the parameter list overlaps a newline
211 boundary, see the BUGS section.
212
213 Trailing Blank Space Characters
214 Troff can be confused by blank space characters at the end of a line. It
215 is a wise preventive measure to globally remove all blank spaces from
216 <blank-space><end-of-line> character sequences. Should the need arise to
217 force a blank character at the end of a line, it may be forced with an
218 unpaddable space and the ‘\&’ escape character. For example,
219 ‘string\ \&’.
220
221 Escaping Special Characters
222 Special characters like the newline character ‘\n’, are handled by
223 replacing the ‘\’ with ‘\e’ (e.g. ‘\en’) to preserve the backslash.
224
226 The body of a man page is easily constructed from a basic template found
227 in the file /usr/share/misc/mdoc.template. Several example man pages can
228 also be found in /usr/share/examples/mdoc.
229
230 A manual page template
231 .\" The following requests are required for all man pages.
232 .Dd Month day, year
233 .Os OPERATING_SYSTEM [version/release]
234 .Dt DOCUMENT_TITLE [section number] [volume]
235 .Sh NAME
236 .Nm name
237 .Nd one line description of name
238 .Sh SYNOPSIS
239 .Sh DESCRIPTION
240 .\" The following requests should be uncommented and
241 .\" used where appropriate. This next request is
242 .\" for sections 2 and 3 function return values only.
243 .\" .Sh RETURN VALUE
244 .\" This next request is for sections 1, 6, 7 & 8 only
245 .\" .Sh ENVIRONMENT
246 .\" .Sh FILES
247 .\" .Sh EXAMPLES
248 .\" This next request is for sections 1, 6, 7 & 8 only
249 .\" (command return values (to shell) and
250 .\" fprintf/stderr type diagnostics)
251 .\" .Sh DIAGNOSTICS
252 .\" The next request is for sections 2 and 3 error
253 .\" and signal handling only.
254 .\" .Sh ERRORS
255 .\" .Sh SEE ALSO
256 .\" .Sh CONFORMING TO
257 .\" .Sh HISTORY
258 .\" .Sh AUTHORS
259 .\" .Sh BUGS
260
261 The first items in the template are the macros (.Dd, .Os, .Dt); the docu‐
262 ment date, the operating system the man page or subject source is devel‐
263 oped or modified for, and the man page title (in upper case) along with
264 the section of the manual the page belongs in. These macros identify the
265 page, and are discussed below in TITLE MACROS.
266
267 The remaining items in the template are section headers (.Sh); of which
268 NAME, SYNOPSIS and DESCRIPTION are mandatory. The headers are discussed
269 in PAGE STRUCTURE DOMAIN, after presentation of MANUAL DOMAIN. Several
270 content macros are used to demonstrate page layout macros; reading about
271 content macros before page layout macros is recommended.
272
274 The title macros are the first portion of the page structure domain, but
275 are presented first and separate for someone who wishes to start writing
276 a man page yesterday. Three header macros designate the document title
277 or manual page title, the operating system, and the date of authorship.
278 These macros are one called once at the very beginning of the document
279 and are used to construct the headers and footers only.
280
281 .Dt DOCUMENT_TITLE section# [volume]
282 The document title is the subject of the man page and must be in
283 CAPITALS due to troff limitations. The section number may be
284 1, ..., 8, and if it is specified, the volume title may be omit‐
285 ted. A volume title may be arbitrary or one of the following:
286
287 AMD UNIX Ancestral Manual Documents
288 SMM UNIX System Manager's Manual
289 URM UNIX Reference Manual
290 PRM UNIX Programmer's Manual
291
292 The default volume labeling is URM for sections 1, 6, and 7; SMM
293 for section 8; PRM for sections 2, 3, 4, and 5.
294
295 .Os operating_system release#
296 The name of the operating system should be the common acronym,
297 for example, BSD or FreeBSD or ATT. The release should be the
298 standard release nomenclature for the system specified, for exam‐
299 ple, 4.3, 4.3+Tahoe, V.3, V.4. Unrecognized arguments are dis‐
300 played as given in the page footer. For instance, a typical
301 footer might be:
302
303 .Os 4.3BSD
304
305 or
306 .Os FreeBSD 2.2
307
308 or for a locally produced set
309
310 .Os CS Department
311
312 The Berkeley default, ‘.Os’ without an argument, has been defined
313 as BSD in the site-specific file /usr/share/tmac/mdoc/doc-common.
314 It really should default to LOCAL. Note, if the ‘.Os’ macro is
315 not present, the bottom left corner of the page will be ugly.
316
317 .Dd month day, year
318 The date should be written formally:
319
320 January 25, 1989
321
323 What's in a name...
324 The manual domain macro names are derived from the day to day informal
325 language used to describe commands, subroutines and related files.
326 Slightly different variations of this language are used to describe the
327 three different aspects of writing a man page. First, there is the
328 description of -mdoc macro request usage. Second is the description of a
329 UNIX command with -mdoc macros and third, the description of a command to
330 a user in the verbal sense; that is, discussion of a command in the text
331 of a man page.
332
333 In the first case, troff(1) macros are themselves a type of command; the
334 general syntax for a troff command is:
335
336 .Va argument1 argument2 ... argument9
337
338 The ‘.Va’ is a macro command or request, and anything following it is an
339 argument to be processed. In the second case, the description of a UNIX
340 command using the content macros is a bit more involved; a typical
341 SYNOPSIS command line might be displayed as:
342
343 filter [-flag] infile outfile
344
345 Here, filter is the command name and the bracketed string -flag is a flag
346 argument designated as optional by the option brackets. In -mdoc terms,
347 infile and outfile are called arguments. The macros which formatted the
348 above example:
349
350 .Nm filter
351 .Op Fl flag
352 .Ar infile outfile
353
354 In the third case, discussion of commands and command syntax includes
355 both examples above, but may add more detail. The arguments infile and
356 outfile from the example above might be referred to as operands or file
357 arguments. Some command-line argument lists are quite long:
358
359 make [-eiknqrstv] [-D variable] [-d flags] [-f makefile]
360 [-I directory] [-j max_jobs] [variable=value] [target ...]
361
362 Here one might talk about the command make and qualify the argument
363 makefile, as an argument to the flag, -f, or discuss the optional file
364 operand target. In the verbal context, such detail can prevent confu‐
365 sion, however the -mdoc package does not have a macro for an argument to
366 a flag. Instead the ‘Ar’ argument macro is used for an operand or file
367 argument like target as well as an argument to a flag like variable. The
368 make command line was produced from:
369
370 .Nm make
371 .Op Fl eiknqrstv
372 .Op Fl D Ar variable
373 .Op Fl d Ar flags
374 .Op Fl f Ar makefile
375 .Op Fl I Ar directory
376 .Op Fl j Ar max_jobs
377 .Op Ar variable=value
378 .Bk -words
379 .Op Ar target ...
380 .Ek
381
382 The ‘.Bk’ and ‘.Ek’ macros are explained in Keeps.
383
384 General Syntax
385 The manual domain and general text domain macros share a similar syntax
386 with a few minor deviations: ‘.Ar’, ‘.Fl’, ‘.Nm’, and ‘.Pa’ differ only
387 when called without arguments; ‘.Fn’ and ‘.Xr’ impose an order on their
388 argument lists and the ‘.Op’ and ‘.Fn’ macros have nesting limitations.
389 All content macros are capable of recognizing and properly handling punc‐
390 tuation, provided each punctuation character is separated by a leading
391 space. If a request is given:
392
393 .Li sptr, ptr),
394
395 The result is:
396
397 sptr, ptr),
398
399 The punctuation is not recognized and all is output in the literal font.
400 If the punctuation is separated by a leading white space:
401
402 .Li sptr , ptr ) ,
403
404 The result is:
405
406 sptr, ptr),
407
408 The punctuation is now recognized and is output in the default font dis‐
409 tinguishing it from the strings in literal font.
410
411 To remove the special meaning from a punctuation character escape it with
412 ‘\&’. Troff is limited as a macro language, and has difficulty when pre‐
413 sented with a string containing a member of the mathematical, logical or
414 quotation set:
415
416 {+,-,/,*,%,<,>,<=,>=,=,==,&,`,',"}
417
418 The problem is that troff may assume it is supposed to actually perform
419 the operation or evaluation suggested by the characters. To prevent the
420 accidental evaluation of these characters, escape them with ‘\&’. Typi‐
421 cal syntax is shown in the first content macro displayed below, ‘.Ad’.
422
424 Address Macro
425 The address macro identifies an address construct of the form
426 addr1[,addr2[,addr3]].
427
428 Usage: .Ad address ...
429 .Ad addr1 addr1
430 .Ad addr1 . addr1.
431 .Ad addr1 , file2
432 addr1, file2
433 .Ad f1 , f2 , f3 :
434 f1, f2, f3:
435 .Ad addr ) ) ,
436 addr)),
437
438 It is an error to call ‘.Ad’ without arguments. ‘.Ad’ is callable by
439 other macros and is parsed.
440
441 Author Name
442 The ‘.An’ macro is used to specify the name of the author of the item
443 being documented, or the name of the author of the actual manual page.
444 Any remaining arguments after the name information are assumed to be
445 punctuation.
446
447 Usage: .An author_name
448 .An Joe Author
449 Joe Author
450 .An Joe Author ,
451 Joe Author,
452 .An Joe Author Aq nobody@FreeBSD.ORG
453 Joe Author <nobody@FreeBSD.ORG>
454 .An Joe Author ) ) ,
455 Joe Author)),
456
457 The ‘.An’ macro is parsed and is callable. It is an error to call ‘.An’
458 without any arguments.
459
460 Argument Macro
461 The ‘.Ar’ argument macro may be used whenever a command-line argument is
462 referenced.
463
464 Usage: .Ar argument ...
465 .Ar file ...
466 .Ar file1 file1
467 .Ar file1 . file1.
468 .Ar file1 file2
469 file1 file2
470 .Ar f1 f2 f3 :
471 f1 f2 f3:
472 .Ar file ) ) ,
473 file)),
474
475 If ‘.Ar’ is called without arguments ‘file ...’ is assumed. The ‘.Ar’
476 macro is parsed and is callable.
477
478 Configuration Declaration (section four only)
479 The ‘.Cd’ macro is used to demonstrate a config(8) declaration for a
480 device interface in a section four manual. This macro accepts quoted
481 arguments (double quotes only).
482
483 device le0 at scode? produced by: ‘.Cd device le0 at scode?’.
484
485 Command Modifier
486 The command modifier is identical to the ‘.Fl’ (flag) command with the
487 exception the ‘.Cm’ macro does not assert a dash in front of every argu‐
488 ment. Traditionally flags are marked by the preceding dash, some com‐
489 mands or subsets of commands do not use them. Command modifiers may also
490 be specified in conjunction with interactive commands such as editor com‐
491 mands. See Flags.
492
493 Defined Variables
494 A variable which is defined in an include file is specified by the macro
495 ‘.Dv’.
496
497 Usage: .Dv defined_variable ...
498 .Dv MAXHOSTNAMELEN
499 MAXHOSTNAMELEN
500 .Dv TIOCGPGRP )
501 TIOCGPGRP)
502
503 It is an error to call ‘.Dv’ without arguments. ‘.Dv’ is parsed and is
504 callable.
505
506 Errno's (Section two only)
507 The ‘.Er’ errno macro specifies the error return value for section two
508 library routines. The second example below shows ‘.Er’ used with the
509 ‘.Bq’ general text domain macro, as it would be used in a section two
510 manual page.
511
512 Usage: .Er ERRNOTYPE ...
513 .Er ENOENT
514 ENOENT
515 .Er ENOENT ) ;
516 ENOENT);
517 .Bq Er ENOTDIR
518 [ENOTDIR]
519
520 It is an error to call ‘.Er’ without arguments. The ‘.Er’ macro is
521 parsed and is callable.
522
523 Environment Variables
524 The ‘.Ev’ macro specifies an environment variable.
525
526 Usage: .Ev argument ...
527 .Ev DISPLAY
528 DISPLAY
529 .Ev PATH . PATH.
530 .Ev PRINTER ) ) ,
531 PRINTER)),
532
533 It is an error to call ‘.Ev’ without arguments. The ‘.Ev’ macro is
534 parsed and is callable.
535
536 Function Argument
537 The ‘.Fa’ macro is used to refer to function arguments (parameters) out‐
538 side of the SYNOPSIS section of the manual or inside the SYNOPSIS section
539 should a parameter list be too long for the ‘.Fn’ macro and the enclosure
540 macros ‘.Fo’ and ‘.Fc’ must be used. ‘.Fa’ may also be used to refer to
541 structure members.
542
543 Usage: .Fa function_argument ...
544 .Fa d_namlen ) ) ,
545 d_namlen)),
546 .Fa iov_len iov_len
547
548 It is an error to call ‘.Fa’ without arguments. ‘.Fa’ is parsed and is
549 callable.
550
551 Function Declaration
552 The ‘.Fd’ macro is used in the SYNOPSIS section with section two or three
553 functions. The ‘.Fd’ macro does not call other macros and is not
554 callable by other macros.
555
556 Usage: .Fd include_file (or defined variable)
557
558 In the SYNOPSIS section a ‘.Fd’ request causes a line break if a function
559 has already been presented and a break has not occurred. This leaves a
560 nice vertical space in between the previous function call and the decla‐
561 ration for the next function.
562
563 Flags
564 The ‘.Fl’ macro handles command-line flags. It prepends a dash, ‘-’, to
565 the flag. For interactive command flags, which are not prepended with a
566 dash, the ‘.Cm’ (command modifier) macro is identical, but without the
567 dash.
568
569 Usage: .Fl argument ...
570 .Fl -
571 .Fl cfv -cfv
572 .Fl cfv . -cfv.
573 .Fl s v t -s -v -t
574 .Fl - , --,
575 .Fl xyz ) , -xyz),
576
577 The ‘.Fl’ macro without any arguments results in a dash representing
578 stdin/stdout. Note that giving ‘.Fl’ a single dash, will result in two
579 dashes. The ‘.Fl’ macro is parsed and is callable.
580
581 Functions (library routines)
582 The .Fn macro is modeled on ANSI C conventions.
583
584 Usage: .Fn [type] function [[type] parameters ... ]
585 .Fn getchar getchar()
586 .Fn strlen ) , strlen()),
587 .Fn "int align" "const * char *sptrs", int align(const * char *sptrs),
588
589 It is an error to call ‘.Fn’ without any arguments. The ‘.Fn’ macro is
590 parsed and is callable, note that any call to another macro signals the
591 end of the ‘.Fn’ call (it will close-parenthesis at that point).
592
593 For functions that have more than eight parameters (and this is rare),
594 the macros ‘.Fo’ (function open) and ‘.Fc’ (function close) may be used
595 with ‘.Fa’ (function argument) to get around the limitation. For exam‐
596 ple:
597
598 .Fo "int res_mkquery"
599 .Fa "int op"
600 .Fa "char *dname"
601 .Fa "int class"
602 .Fa "int type"
603 .Fa "char *data"
604 .Fa "int datalen"
605 .Fa "struct rrec *newrr"
606 .Fa "char *buf"
607 .Fa "int buflen"
608 .Fc
609
610 Produces:
611
612 int res_mkquery(int op, char *dname, int class, int type,
613 char *data, int datalen, struct rrec *newrr, char *buf, int buflen)
614
615 The ‘.Fo’ and ‘.Fc’ macros are parsed and are callable. In the SYNOPSIS
616 section, the function will always begin at the beginning of line. If
617 there is more than one function presented in the SYNOPSIS section and a
618 function type has not been given, a line break will occur, leaving a nice
619 vertical space between the current function name and the one prior. At
620 the moment, ‘.Fn’ does not check its word boundaries against troff line
621 lengths and may split across a newline ungracefully. This will be fixed
622 in the near future.
623
624 Function Type
625 This macro is intended for the SYNOPSIS section. It may be used anywhere
626 else in the man page without problems, but its main purpose is to present
627 the function type in kernel normal form for the SYNOPSIS of sections two
628 and three (it causes a line break allowing the function name to appear on
629 the next line).
630
631 Usage: .Ft type ...
632 .Ft struct stat struct stat
633
634 The ‘.Ft’ request is not callable by other macros.
635
636 Interactive Commands
637 The ‘.Ic’ macro designates an interactive or internal command.
638
639 Usage: .Ic argument ...
640 .Ic :wq :wq
641 .Ic do while {...} do while {...}
642 .Ic setenv , unsetenv
643 setenv, unsetenv
644
645 It is an error to call ‘.Ic’ without arguments. The ‘.Ic’ macro is
646 parsed and is callable.
647
648 Name Macro
649 The ‘.Nm’ macro is used for the document title or subject name. It has
650 the peculiarity of remembering the first argument it was called with,
651 which should always be the subject name of the page. When called without
652 arguments, ‘.Nm’ regurgitates this initial name for the sole purpose of
653 making less work for the author. Note: a section two or three document
654 function name is addressed with the ‘.Nm’ in the NAME section, and with
655 ‘.Fn’ in the SYNOPSIS and remaining sections. For interactive commands,
656 such as the ‘while’ command keyword in csh(1), the ‘.Ic’ macro should be
657 used. While the ‘.Ic’ is nearly identical to ‘.Nm’, it can not recall
658 the first argument it was invoked with.
659
660 Usage: .Nm argument ...
661 .Nm mdoc.sample
662 mdoc.sample
663 .Nm \-mdoc -mdoc.
664 .Nm foo ) ) ,
665 foo)),
666 .Nm mdoc.samples
667
668 The ‘.Nm’ macro is parsed and is callable.
669
670 Options
671 The ‘.Op’ macro places option brackets around the any remaining arguments
672 on the command line, and places any trailing punctuation outside the
673 brackets. The macros ‘.Oc’ and ‘.Oo’ may be used across one or more
674 lines.
675
676 Usage: .Op options ...
677 .Op []
678 .Op Fl k [-k]
679 .Op Fl k ) . [-k]).
680 .Op Fl k Ar kookfile [-k kookfile]
681 .Op Fl k Ar kookfile ,
682 [-k kookfile],
683 .Op Ar objfil Op Ar corfil
684 [objfil [corfil]]
685 .Op Fl c Ar objfil Op Ar corfil ,
686 [-c objfil [corfil]],
687 .Op word1 word2 [word1 word2]
688
689 The ‘.Oc’ and ‘.Oo’ macros:
690
691 .Oo
692 .Op Fl k Ar kilobytes
693 .Op Fl i Ar interval
694 .Op Fl c Ar count
695 .Oc
696
697 Produce: [[-k kilobytes] [-i interval] [-c count]]
698
699 The macros ‘.Op’, ‘.Oc’ and ‘.Oo’ are parsed and are callable.
700
701 Pathnames
702 The ‘.Pa’ macro formats pathnames or filenames.
703
704 Usage: .Pa pathname
705 .Pa /usr/share /usr/share
706 .Pa /tmp/fooXXXXX ) .
707 /tmp/fooXXXXX).
708
709 The ‘.Pa’ macro is parsed and is callable.
710
711 Variables
712 Generic variable reference:
713
714 Usage: .Va variable ...
715 .Va count count
716 .Va settimer,
717 settimer,
718 .Va int *prt ) :
719 int *prt):
720 .Va char s ] ) ) ,
721 char s])),
722
723 It is an error to call ‘.Va’ without any arguments. The ‘.Va’ macro is
724 parsed and is callable.
725
726 Manual Page Cross References
727 The ‘.Xr’ macro expects the first argument to be a manual page name, and
728 the second argument, if it exists, to be either a section page number or
729 punctuation. Any remaining arguments are assumed to be punctuation.
730
731 Usage: .Xr man_page [1,...,8]
732 .Xr mdoc mdoc
733 .Xr mdoc , mdoc,
734 .Xr mdoc 7 mdoc(7)
735 .Xr mdoc 7 ) ) ,
736 mdoc(7))),
737
738 The ‘.Xr’ macro is parsed and is callable. It is an error to call ‘.Xr’
739 without any arguments.
740
742 AT&T Macro
743 Usage: .At [v6 | v7 | 32v | V.1 | V.4] ...
744 .At AT&T UNIX
745 .At v6 . Version 6 AT&T UNIX.
746
747 The ‘.At’ macro is not parsed and not callable It accepts at most two
748 arguments.
749
750 BSD Macro
751 Usage: .Bx [Version/release] ...
752 .Bx BSD
753 .Bx 4.3 .
754 4.3BSD.
755
756 The ‘.Bx’ macro is parsed and is callable.
757
758 FreeBSD Macro
759 Usage: .Fx Version.release ...
760 .Fx 2.2 . FreeBSD 2.2.
761
762 The ‘.Fx’ macro is not parsed and not callable It accepts at most two
763 arguments.
764
765 UNIX Macro
766 Usage: .Ux ...
767 .Ux UNIX
768
769 The ‘.Ux’ macro is parsed and is callable.
770
771 Enclosure and Quoting Macros
772 The concept of enclosure is similar to quoting. The object being to
773 enclose one or more strings between a pair of characters like quotes or
774 parentheses. The terms quoting and enclosure are used interchangeably
775 throughout this document. Most of the one line enclosure macros end in
776 small letter ‘q’ to give a hint of quoting, but there are a few irregu‐
777 larities. For each enclosure macro there is also a pair of open and
778 close macros which end in small letters ‘o’ and ‘c’ respectively. These
779 can be used across one or more lines of text and while they have nesting
780 limitations, the one line quote macros can be used inside of them.
781
782 Quote Close Open Function Result
783 .Aq .Ac .Ao Angle Bracket Enclosure <string>
784 .Bq .Bc .Bo Bracket Enclosure [string]
785 .Dq .Dc .Do Double Quote ``string''
786 .Ec .Eo Enclose String (in XX) XXstringXX
787 .Pq .Pc .Po Parenthesis Enclosure (string)
788 .Ql Quoted Literal `st' or string
789 .Qq .Qc .Qo Straight Double Quote "string"
790 .Sq .Sc .So Single Quote `string'
791
792 Except for the irregular macros noted below, all of the quoting macros
793 are parsed and callable. All handle punctuation properly, as long as it
794 is presented one character at a time and separated by spaces. The quot‐
795 ing macros examine opening and closing punctuation to determine whether
796 it comes before or after the enclosing string This makes some nesting
797 possible.
798
799 .Ec, .Eo These macros expect the first argument to be the opening and
800 closing strings respectively.
801
802 .Ql The quoted literal macro behaves differently for troff than
803 nroff. If formatted with nroff, a quoted literal is always
804 quoted. If formatted with troff, an item is only quoted if the
805 width of the item is less than three constant width characters.
806 This is to make short strings more visible where the font
807 change to literal (constant width) is less noticeable.
808
809 .Pf The prefix macro is not callable, but it is parsed:
810
811 .Pf ( Fa name2
812 becomes (name2.
813
814 The ‘.Ns’ (no space) macro performs the analogous suffix func‐
815 tion.
816
817 Examples of quoting:
818 .Aq ⟨⟩
819 .Aq Ar ctype.h ) , ⟨ctype.h⟩),
820 .Bq []
821 .Bq Em Greek , French .
822 [Greek, French].
823 .Dq “”
824 .Dq string abc . “string abc”.
825 .Dq ´^[A-Z]´ “´^[A-Z]´”
826 .Ql man mdoc ‘man mdoc’
827 .Qq ""
828 .Qq string ) , "string"),
829 .Qq string Ns ), "string),"
830 .Sq ‘’
831 .Sq string ‘string’
832
833 For a good example of nested enclosure macros, see the ‘.Op’ option
834 macro. It was created from the same underlying enclosure macros as those
835 presented in the list above. The ‘.Xo’ and ‘.Xc’ extended argument list
836 macros were also built from the same underlying routines and are a good
837 example of -mdoc macro usage at its worst.
838
839 No-Op or Normal Text Macro
840 The macro ‘.No’ is a hack for words in a macro command line which should
841 not be formatted and follows the conventional syntax for content macros.
842
843 Space Macro
844 The ‘.Ns’ macro eliminates unwanted spaces in between macro requests. It
845 is useful for old style argument lists where there is no space between
846 the flag and argument:
847
848 .Op Fl I Ns Ar directory
849 produces [-Idirectory]
850
851 Note: the ‘.Ns’ macro always invokes the ‘.No’ macro after eliminating
852 the space unless another macro name follows it. The macro ‘.Ns’ is
853 parsed and is callable.
854
855 Section Cross References
856 The ‘.Sx’ macro designates a reference to a section header within the
857 same document. It is parsed and is callable.
858
859 .Sx FILES FILES
860
861 References and Citations
862 The following macros make a modest attempt to handle references. At
863 best, the macros make it convenient to manually drop in a subset of refer
864 style references.
865
866 .Rs Reference Start. Causes a line break and begins collection
867 of reference information until the reference end macro is
868 read.
869 .Re Reference End. The reference is printed.
870 .%A Reference author name, one name per invocation.
871 .%B Book title.
872 .%C City/place.
873 .%D Date.
874 .%J Journal name.
875 .%N Issue number.
876 .%O Optional information.
877 .%P Page number.
878 .%R Report name.
879 .%T Title of article.
880 .%V Volume(s).
881
882 The macros beginning with ‘%’ are not callable, and are parsed only for
883 the trade name macro which returns to its caller. (And not very pre‐
884 dictably at the moment either.) The purpose is to allow trade names to
885 be pretty printed in troff/ditroff output.
886
887 Return Values
888 The ‘.Rv’ macro generates text for use in the RETURN VALUE section.
889
890 Usage: .Rv [-std function]
891
892 ‘.Rv -std atexit’ will generate the following text:
893
894 The atexit() function returns the value 0 if successful; otherwise the
895 value -1 is returned and the global variable errno is set to indicate the
896 error.
897
898 The -std option is valid only for manual page sections 2 and 3.
899
900 Trade Names (or Acronyms and Type Names)
901 The trade name macro is generally a small caps macro for all upper case
902 words longer than two characters.
903
904 Usage: .Tn symbol ...
905 .Tn DEC
906 DEC
907 .Tn ASCII
908 ASCII
909
910 The ‘.Tn’ macro is parsed and is callable by other macros.
911
912 Extended Arguments
913 The ‘.Xo’ and ‘.Xc’ macros allow one to extend an argument list on a
914 macro boundary. Argument lists cannot be extended within a macro which
915 expects all of its arguments on one line such as ‘.Op’.
916
917 Here is an example of ‘.Xo’ using the space mode macro to turn spacing
918 off:
919
920 .Sm off
921 .It Xo Sy I Ar operation
922 .No \en Ar count No \en
923 .Xc
924 .Sm on
925
926 Produces
927
928 Ioperation\ncount\n
929
930 Another one:
931
932 .Sm off
933 .It Cm S No / Ar old_pattern Xo
934 .No / Ar new_pattern
935 .No / Op Cm g
936 .Xc
937 .Sm on
938
939 Produces
940
941 S/old_pattern/new_pattern/[g]
942
943 Another example of ‘.Xo’ and using enclosure macros: Test the value of a
944 variable.
945
946 .It Xo
947 .Ic .ifndef
948 .Oo \&! Oc Ns Ar variable
949 .Op Ar operator variable ...
950 .Xc
951
952 Produces
953
954 .ifndef [!]variable [operator variable ...]
955
956 All of the above examples have used the ‘.Xo’ macro on the argument list
957 of the ‘.It’ (list-item) macro. The extend macros are not used very
958 often, and when they are it is usually to extend the list-item argument
959 list. Unfortunately, this is also where the extend macros are the most
960 finicky. In the first two examples, spacing was turned off; in the
961 third, spacing was desired in part of the output but not all of it. To
962 make these macros work in this situation make sure the ‘.Xo’ and ‘.Xc’
963 macros are placed as shown in the third example. If the ‘.Xo’ macro is
964 not alone on the ‘.It’ argument list, spacing will be unpredictable. The
965 ‘.Ns’ (no space macro) must not occur as the first or last macro on a
966 line in this situation. Out of 900 manual pages (about 1500 actual
967 pages) currently released with BSD only fifteen use the ‘.Xo’ macro.
968
970 Section Headers
971 The first three ‘.Sh’ section header macros list below are required in
972 every man page. The remaining section headers are recommended at the
973 discretion of the author writing the manual page. The ‘.Sh’ macro can
974 take up to nine arguments. It is parsed and but is not callable.
975
976 .Sh NAME The ‘.Sh NAME’ macro is mandatory. If not specified, the head‐
977 ers, footers and page layout defaults will not be set and
978 things will be rather unpleasant. The NAME section consists of
979 at least three items. The first is the ‘.Nm’ name macro naming
980 the subject of the man page. The second is the Name Descrip‐
981 tion macro, ‘.Nd’, which separates the subject name from the
982 third item, which is the description. The description should
983 be the most terse and lucid possible, as the space available is
984 small.
985
986 .Sh SYNOPSIS
987 The SYNOPSIS section describes the typical usage of the subject
988 of a man page. The macros required are either ‘.Nm’, ‘.Cd’,
989 ‘.Fn’, (and possibly ‘.Fo’, ‘.Fc’, ‘.Fd’, ‘.Ft’ macros). The
990 function name macro ‘.Fn’ is required for manual page sections
991 2 and 3, the command and general name macro ‘.Nm’ is required
992 for sections 1, 5, 6, 7, 8. Section 4 manuals require a ‘.Nm’,
993 ‘.Fd’ or a ‘.Cd’ configuration device usage macro. Several
994 other macros may be necessary to produce the synopsis line as
995 shown below:
996
997 cat [-benstuv] [-] file ...
998
999 The following macros were used:
1000
1001 .Nm cat
1002 .Op Fl benstuv
1003 .Op Fl
1004 .Ar
1005
1006 Note: The macros ‘.Op’, ‘.Fl’, and ‘.Ar’ recognize the pipe bar
1007 character ‘|’, so a command line such as:
1008
1009 .Op Fl a | Fl b
1010
1011 will not go orbital. Troff normally interprets a | as a spe‐
1012 cial operator. See PREDEFINED STRINGS for a usable | character
1013 in other situations.
1014
1015 .Sh DESCRIPTION
1016 In most cases the first text in the DESCRIPTION section is a
1017 brief paragraph on the command, function or file, followed by a
1018 lexical list of options and respective explanations. To create
1019 such a list, the ‘.Bl’ begin-list, ‘.It’ list-item and ‘.El’
1020 end-list macros are used (see Lists and Columns below).
1021
1022 The following ‘.Sh’ section headers are part of the preferred manual page
1023 layout and must be used appropriately to maintain consistency. They are
1024 listed in the order in which they would be used.
1025
1026 .Sh ENVIRONMENT
1027 The ENVIRONMENT section should reveal any related environment
1028 variables and clues to their behavior and/or usage.
1029
1030 .Sh EXAMPLES
1031 There are several ways to create examples. See the EXAMPLES
1032 section below for details.
1033
1034 .Sh FILES
1035 Files which are used or created by the man page subject should
1036 be listed via the ‘.Pa’ macro in the FILES section.
1037
1038 .Sh SEE ALSO
1039 References to other material on the man page topic and cross
1040 references to other relevant man pages should be placed in the
1041 SEE ALSO section. Cross references are specified using the
1042 ‘.Xr’ macro. Cross references in the SEE ALSO section should
1043 be sorted by section number, and then placed in alphabetical
1044 order and comma separated. For example:
1045
1046 ls(1), ps(1), group(5), passwd(5).
1047
1048 At this time refer(1) style references are not accommodated.
1049
1050 .Sh CONFORMING TO
1051 If the command, library function or file adheres to a specific
1052 implementation such as IEEE Std 1003.2 (“POSIX.2”) or ANSI
1053 X3.159-1989 (“ANSI C89”) this should be noted here. If the
1054 command does not adhere to any standard, its history should be
1055 noted in the HISTORY section.
1056
1057 .Sh HISTORY
1058 Any command which does not adhere to any specific standards
1059 should be outlined historically in this section.
1060
1061 .Sh AUTHORS
1062 Credits, if need be, should be placed here.
1063
1064 .Sh DIAGNOSTICS
1065 Diagnostics from a command should be placed in this section.
1066
1067 .Sh ERRORS
1068 Specific error handling, especially from library functions (man
1069 page sections 2 and 3) should go here. The ‘.Er’ macro is used
1070 to specify an errno.
1071
1072 .Sh BUGS Blatant problems with the topic go here...
1073
1074 User specified ‘.Sh’ sections may be added, for example, this section was
1075 set with:
1076
1077 .Sh PAGE STRUCTURE DOMAIN
1078
1079 Paragraphs and Line Spacing.
1080 .Pp The ‘.Pp’ paragraph command may be used to specify a line space
1081 where necessary. The macro is not necessary after a ‘.Sh’ or
1082 ‘.Ss’ macro or before a ‘.Bl’ macro. (The ‘.Bl’ macro asserts a
1083 vertical distance unless the -compact flag is given).
1084
1085 Keeps
1086 The only keep that is implemented at this time is for words. The macros
1087 are ‘.Bk’ (begin-keep) and ‘.Ek’ (end-keep). The only option that ‘.Bk’
1088 accepts is -words and is useful for preventing line breaks in the middle
1089 of options. In the example for the make command-line arguments (see
1090 What's in a name), the keep prevented nroff from placing up the flag and
1091 the argument on separate lines. (Actually, the option macro used to pre‐
1092 vent this from occurring, but was dropped when the decision (religious)
1093 was made to force right justified margins in troff as options in general
1094 look atrocious when spread across a sparse line. More work needs to be
1095 done with the keep macros, a -line option needs to be added.)
1096
1097 Examples and Displays
1098 There are five types of displays, a quickie one line indented display
1099 ‘.D1’, a quickie one line literal display ‘.Dl’, and a block literal,
1100 block filled and block ragged which use the ‘.Bd’ begin-display and ‘.Ed’
1101 end-display macros.
1102
1103 .D1 (D-one) Display one line of indented text. This macro is parsed,
1104 but it is not callable.
1105
1106 -ldghfstru
1107
1108 The above was produced by: .Dl -ldghfstru.
1109
1110 .Dl (D-ell) Display one line of indented literal text. The ‘.Dl’
1111 example macro has been used throughout this file. It allows the
1112 indent (display) of one line of text. Its default font is set to
1113 constant width (literal) however it is parsed and will recognized
1114 other macros. It is not callable however.
1115
1116 % ls -ldg /usr/local/bin
1117
1118 The above was produced by .Dl % ls -ldg /usr/local/bin.
1119
1120 .Bd Begin-display. The ‘.Bd’ display must be ended with the ‘.Ed’
1121 macro. Displays may be nested within displays and lists. ‘.Bd’
1122 has the following syntax:
1123
1124 .Bd display-type [-offset offset_value] [-compact]
1125
1126 The display-type must be one of the following four types and may
1127 have an offset specifier for indentation: ‘.Bd’.
1128
1129 -ragged Display a block of text as typed, right (and
1130 left) margin edges are left ragged.
1131 -filled Display a filled (formatted) block. The block
1132 of text is formatted (the edges are filled - not
1133 left unjustified).
1134 -literal Display a literal block, useful for source code
1135 or simple tabbed or spaced text.
1136 -file file_name The filename following the -file flag is read
1137 and displayed. Literal mode is asserted and
1138 tabs are set at 8 constant width character
1139 intervals, however any troff/-mdoc commands in
1140 file will be processed.
1141 -offset string If -offset is specified with one of the follow‐
1142 ing strings, the string is interpreted to indi‐
1143 cate the level of indentation for the forthcom‐
1144 ing block of text:
1145
1146 left Align block on the current left mar‐
1147 gin, this is the default mode of
1148 ‘.Bd’.
1149 center Supposedly center the block. At
1150 this time unfortunately, the block
1151 merely gets left aligned about an
1152 imaginary center margin.
1153 indent Indents by one default indent value
1154 or tab. The default indent value is
1155 also used for the ‘.D1’ display so
1156 one is guaranteed the two types of
1157 displays will line up. This indent
1158 is normally set to 6n or about two
1159 thirds of an inch (six constant
1160 width characters).
1161 indent-two Indents two times the default indent
1162 value.
1163 right This left aligns the block about two
1164 inches from the right side of the
1165 page. This macro needs work and
1166 perhaps may never do the right thing
1167 by troff.
1168
1169 .Ed End-display.
1170
1171 Font Modes
1172 There are five macros for changing the appearance of the manual page
1173 text:
1174
1175 .Em Text may be stressed or emphasized with the ‘.Em’ macro. The
1176 usual font for emphasis is italic.
1177
1178 Usage: .Em argument ...
1179 .Em does not does not
1180 .Em exceed 1024 .
1181 exceed 1024.
1182 .Em vide infra ) ) ,
1183 vide infra)),
1184
1185 The ‘.Em’ macro is parsed and is callable. It is an error to call
1186 ‘.Em’ without arguments.
1187
1188 .Li The ‘.Li’ literal macro may be used for special characters, vari‐
1189 able constants, anything which should be displayed as it would be
1190 typed.
1191
1192 Usage: .Li argument ...
1193 .Li \en \n
1194 .Li M1 M2 M3 ;
1195 M1 M2 M3;
1196 .Li cntrl-D ) ,
1197 cntrl-D),
1198 .Li 1024 ...
1199 1024 ...
1200
1201 The ‘.Li’ macro is parsed and is callable.
1202
1203 .Sy The symbolic emphasis macro is generally a boldface macro in
1204 either the symbolic sense or the traditional English usage.
1205
1206 Usage: .Sy symbol ...
1207 .Sy Important Notice
1208 Important Notice
1209
1210 The ‘.Sy’ macro is parsed and is callable. Arguments to ‘.Sy’ may
1211 be quoted.
1212
1213 .Bf Begin font mode. The ‘.Bf’ font mode must be ended with the ‘.Ef’
1214 macro. Font modes may be nested within other font modes. ‘.Bf’
1215 has the following syntax:
1216
1217 .Bf font-mode
1218
1219 The font-mode must be one of the following three types: ‘.Bf’.
1220
1221 Em | -emphasis Same as if the ‘.Em’ macro was used for the
1222 entire block of text.
1223 Li | -literal Same as if the ‘.Li’ macro was used for the
1224 entire block of text.
1225 Sy | -symbolic Same as if the ‘.Sy’ macro was used for the
1226 entire block of text.
1227
1228 .Ef End font mode.
1229
1230 Tagged Lists and Columns
1231 There are several types of lists which may be initiated with the ‘.Bl’
1232 begin-list macro. Items within the list are specified with the ‘.It’
1233 item macro and each list must end with the ‘.El’ macro. Lists may be
1234 nested within themselves and within displays. Columns may be used inside
1235 of lists, but lists are unproven inside of columns.
1236
1237 In addition, several list attributes may be specified such as the width
1238 of a tag, the list offset, and compactness (blank lines between items
1239 allowed or disallowed). Most of this document has been formatted with a
1240 tag style list (-tag). For a change of pace, the list-type used to
1241 present the list-types is an over-hanging list (-ohang). This type of
1242 list is quite popular with TeX users, but might look a bit funny after
1243 having read many pages of tagged lists. The following list types are
1244 accepted by ‘.Bl’:
1245
1246 -bullet
1247 -item
1248 -enum
1249 These three are the simplest types of lists. Once the ‘.Bl’ macro has
1250 been given, items in the list are merely indicated by a line consisting
1251 solely of the ‘.It’ macro. For example, the source text for a simple
1252 enumerated list would look like:
1253
1254 .Bl -enum -compact
1255 .It
1256 Item one goes here.
1257 .It
1258 And item two here.
1259 .It
1260 Lastly item three goes here.
1261 .El
1262
1263 The results:
1264
1265 1. Item one goes here.
1266 2. And item two here.
1267 3. Lastly item three goes here.
1268
1269 A simple bullet list construction:
1270
1271 .Bl -bullet -compact
1272 .It
1273 Bullet one goes here.
1274 .It
1275 Bullet two here.
1276 .El
1277
1278 Produces:
1279 · Bullet one goes here.
1280 · Bullet two here.
1281
1282 -tag
1283 -diag
1284 -hang
1285 -ohang
1286 -inset
1287 These list-types collect arguments specified with the ‘.It’ macro and
1288 create a label which may be inset into the forthcoming text, hanged from
1289 the forthcoming text, overhanged from above and not indented or tagged.
1290 This list was constructed with the ‘-ohang’ list-type. The ‘.It’ macro
1291 is parsed only for the inset, hang and tag list-types and is not
1292 callable. Here is an example of inset labels:
1293
1294 Tag The tagged list (also called a tagged paragraph) is the most
1295 common type of list used in the Berkeley manuals.
1296
1297 Diag Diag lists create section four diagnostic lists and are simi‐
1298 lar to inset lists except callable macros are ignored.
1299
1300 Hang Hanged labels are a matter of taste.
1301
1302 Ohang Overhanging labels are nice when space is constrained.
1303
1304 Inset Inset labels are useful for controlling blocks of paragraphs
1305 and are valuable for converting -mdoc manuals to other formats.
1306
1307 Here is the source text which produced the above example:
1308
1309 .Bl -inset -offset indent
1310 .It Em Tag
1311 The tagged list (also called a tagged paragraph) is the
1312 most common type of list used in the Berkeley manuals.
1313 .It Em Diag
1314 Diag lists create section four diagnostic lists
1315 and are similar to inset lists except callable
1316 macros are ignored.
1317 .It Em Hang
1318 Hanged labels are a matter of taste.
1319 .It Em Ohang
1320 Overhanging labels are nice when space is constrained.
1321 .It Em Inset
1322 Inset labels are useful for controlling blocks of
1323 paragraphs and are valuable for converting
1324 .Nm -mdoc
1325 manuals to other formats.
1326 .El
1327
1328 Here is a hanged list with two items:
1329
1330 Hanged labels appear similar to tagged lists when the label is
1331 smaller than the label width.
1332
1333 Longer hanged list labels blend in to the paragraph unlike tagged
1334 paragraph labels.
1335
1336 And the unformatted text which created it:
1337
1338 .Bl -hang -offset indent
1339 .It Em Hanged
1340 labels appear similar to tagged lists when the
1341 label is smaller than the label width.
1342 .It Em Longer hanged list labels
1343 blend in to the paragraph unlike
1344 tagged paragraph labels.
1345 .El
1346
1347 The tagged list which follows uses an optional width specifier to control
1348 the width of the tag.
1349
1350 SL sleep time of the process (seconds blocked)
1351 PAGEIN number of disk I/O's resulting from references by the
1352 process to pages not loaded in core.
1353 UID numerical user-id of process owner
1354 PPID numerical ID of parent of process process priority (nonpos‐
1355 itive when in noninterruptible wait)
1356
1357 The raw text:
1358
1359 .Bl -tag -width "PAGEIN" -compact -offset indent
1360 .It SL
1361 sleep time of the process (seconds blocked)
1362 .It PAGEIN
1363 number of disk
1364 .Tn I/O Ns 's
1365 resulting from references
1366 by the process to pages not loaded in core.
1367 .It UID
1368 numerical user ID of process owner
1369 .It PPID
1370 numerical ID of parent of process process priority
1371 (nonpositive when in noninterruptible wait)
1372 .El
1373
1374 Acceptable width specifiers:
1375
1376 -width Fl sets the width to the default width for a flag. All
1377 callable macros have a default width value. The
1378 ‘.Fl’, value is presently set to ten constant width
1379 characters or about five sixth of an inch.
1380
1381 -width 24n sets the width to 24 constant width characters or
1382 about two inches. The ‘n’ is absolutely necessary
1383 for the scaling to work correctly.
1384
1385 -width ENAMETOOLONG
1386 sets width to the constant width length of the string
1387 given.
1388
1389 -width "int mkfifo"
1390 again, the width is set to the constant width of the
1391 string given.
1392
1393 If a width is not specified for the tag list type, the first time ‘.It’
1394 is invoked, an attempt is made to determine an appropriate width. If the
1395 first argument to ‘.It’ is a callable macro, the default width for that
1396 macro will be used as if the macro name had been supplied as the width.
1397 However, if another item in the list is given with a different callable
1398 macro name, a new and nested list is assumed.
1399
1401 The following strings are predefined as may be used by preceding with the
1402 troff string interpreting sequence ‘\*(xx’ where xx is the name of the
1403 defined string or as ‘\*x’ where x is the name of the string. The inter‐
1404 preting sequence may be used any where in the text.
1405
1406 String Nroff Troff
1407 <= <= ≤
1408 >= >= ≥
1409 Rq '' ”
1410 Lq `` “
1411 ua ^ ↑
1412 aa ' ´
1413 ga ` `
1414 q " "
1415 Pi pi π
1416 Ne != ≠
1417 Le <= ≤
1418 Ge >= ≥
1419 Lt < >
1420 Gt > <
1421 Pm +- ±
1422 If infinity ∞
1423 Na NaN NaN
1424 Ba | |
1425
1426 Note: The string named ‘q’ should be written as ‘\*q’ since it is only
1427 one char.
1428
1430 The debugging facilities for -mdoc are limited, but can help detect sub‐
1431 tle errors such as the collision of an argument name with an internal
1432 register or macro name. (A what?) A register is an arithmetic storage
1433 class for troff with a one or two character name. All registers internal
1434 to -mdoc for troff and ditroff are two characters and of the form
1435 <upper_case><lower_case> such as ‘Ar’, <lower_case><upper_case> as ‘aR’
1436 or <upper or lower letter><digit> as ‘C1’. And adding to the muddle,
1437 troff has its own internal registers all of which are either two lower
1438 case characters or a dot plus a letter or metacharacter character. In
1439 one of the introduction examples, it was shown how to prevent the inter‐
1440 pretation of a macro name with the escape sequence ‘\&’. This is suffi‐
1441 cient for the internal register names also.
1442
1443 If a nonescaped register name is given in the argument list of a request
1444 unpredictable behavior will occur. In general, any time huge portions of
1445 text do not appear where expected in the output, or small strings such as
1446 list tags disappear, chances are there is a misunderstanding about an
1447 argument type in the argument list. Your mother never intended for you
1448 to remember this evil stuff - so here is a way to find out whether or not
1449 your arguments are valid: The ‘.Db’ (debug) macro displays the interpre‐
1450 tation of the argument list for most macros. Macros such as the ‘.Pp’
1451 (paragraph) macro do not contain debugging information. All of the
1452 callable macros do, and it is strongly advised whenever in doubt, turn on
1453 the ‘.Db’ macro.
1454
1455 Usage: .Db [on | off]
1456
1457 An example of a portion of text with the debug macro placed above and
1458 below an artificially created problem (a flag argument ‘aC’ which should
1459 be ‘\&aC’ in order to work):
1460
1461 .Db on
1462 .Op Fl aC Ar file )
1463 .Db off
1464
1465 The resulting output:
1466
1467 DEBUGGING ON
1468 DEBUG(argv) MACRO: `.Op' Line #: 2
1469 Argc: 1 Argv: `Fl' Length: 2
1470 Space: `' Class: Executable
1471 Argc: 2 Argv: `aC' Length: 2
1472 Space: `' Class: Executable
1473 Argc: 3 Argv: `Ar' Length: 2
1474 Space: `' Class: Executable
1475 Argc: 4 Argv: `file' Length: 4
1476 Space: ` ' Class: String
1477 Argc: 5 Argv: `)' Length: 1
1478 Space: ` ' Class: Closing Punctuation or suffix
1479 MACRO REQUEST: .Op Fl aC Ar file )
1480 DEBUGGING OFF
1481
1482 The first line of information tells the name of the calling macro, here
1483 ‘.Op’, and the line number it appears on. If one or more files are
1484 involved (especially if text from another file is included) the line num‐
1485 ber may be bogus. If there is only one file, it should be accurate. The
1486 second line gives the argument count, the argument (‘Fl’) and its length.
1487 If the length of an argument is two characters, the argument is tested to
1488 see if it is executable (unfortunately, any register which contains a
1489 nonzero value appears executable). The third line gives the space allot‐
1490 ted for a class, and the class type. The problem here is the argument aC
1491 should not be executable. The four types of classes are string, exe‐
1492 cutable, closing punctuation and opening punctuation. The last line
1493 shows the entire argument list as it was read. In this next example, the
1494 offending ‘aC’ is escaped:
1495
1496 .Db on
1497 .Em An escaped \&aC
1498 .Db off
1499
1500 DEBUGGING ON
1501 DEBUG(fargv) MACRO: `.Em' Line #: 2
1502 Argc: 1 Argv: `An' Length: 2
1503 Space: ` ' Class: String
1504 Argc: 2 Argv: `escaped' Length: 7
1505 Space: ` ' Class: String
1506 Argc: 3 Argv: `aC' Length: 2
1507 Space: ` ' Class: String
1508 MACRO REQUEST: .Em An escaped &aC
1509 DEBUGGING OFF
1510
1511 The argument ‘\&aC’ shows up with the same length of 2 as the ‘\&’
1512 sequence produces a zero width, but a register named ‘\&aC’ was not found
1513 and the type classified as string.
1514
1515 Other diagnostics consist of usage statements and are self explanatory.
1516
1518 The -mdoc package does not need compatibility mode with groff.
1519
1520 The package inhibits page breaks, and the headers and footers which nor‐
1521 mally occur at those breaks with nroff, to make the manual more efficient
1522 for viewing on-line. At the moment, groff with -Tascii does eject the
1523 imaginary remainder of the page at end of file. The inhibiting of the
1524 page breaks makes nroff'd files unsuitable for hardcopy. There is a reg‐
1525 ister named ‘cR’ which can be set to zero in the site dependent style
1526 file /usr/src/share/tmac/doc-nroff to restore the old style behavior.
1527
1529 /usr/share/tmac/doc.tmac manual macro package
1530 /usr/share/misc/mdoc.template
1531 template for writing a man page
1532 /usr/share/examples/mdoc/* several example man pages
1533
1535 Undesirable hyphenation on the dash of a flag argument is not yet
1536 resolved, and causes occasional mishaps in the DESCRIPTION section.
1537 (line break on the hyphen).
1538
1539 Predefined strings are not declared in documentation.
1540
1541 Section 3f has not been added to the header routines.
1542
1543 ‘.Nm’ font should be changed in NAME section.
1544
1545 ‘.Fn’ needs to have a check to prevent splitting up if the line length is
1546 too short. Occasionally it separates the last parenthesis, and sometimes
1547 looks ridiculous if a line is in fill mode.
1548
1549 The method used to prevent header and footer page breaks (other than the
1550 initial header and footer) when using nroff occasionally places an
1551 unsightly partially filled line (blank) at the would be bottom of the
1552 page.
1553
1554 The list and display macros to not do any keeps and certainly should be
1555 able to.
1556
1558 man(1), troff(1), groff_mdoc(7), mdoc(7)
1559
1561 This page is part of release 3.25 of the Linux man-pages project. A
1562 description of the project, and information about reporting bugs, can be
1563 found at http://www.kernel.org/doc/man-pages/.
1564
1565BSD December 30, 1993 BSD