man-pages(7) Miscellaneous Information Manual man-pages(7)
NAME
man-pages - conventions for writing Linux man pages
SYNOPSIS
man [section] title
DESCRIPTION
This page describes the conventions that should be employed when writing
man pages for the Linux man-pages project, which documents the user-
space API provided by the Linux kernel and the GNU C library. The
project thus provides most of the pages in Section 2, many of the pages
that appear in Sections 3, 4, and 7, and a few of the pages that appear
in Sections 1, 5, and 8 of the man pages on a Linux system. The conven-
tions described on this page may also be useful for authors writing man
pages for other projects.
Sections of the manual pages
The manual Sections are traditionally defined as follows:
1 User commands (Programs)
Commands that can be executed by the user from within a shell.
2 System calls
Functions which wrap operations performed by the kernel.
3 Library calls
All library functions excluding the system call wrappers (Most of
the libc functions).
4 Special files (devices)
Files found in /dev which allow to access to devices through the
kernel.
5 File formats and configuration files
Describes various human-readable file formats and configuration
files.
6 Games
Games and funny little programs available on the system.
7 Overview, conventions, and miscellaneous
Overviews or descriptions of various topics, conventions, and
protocols, character set standards, the standard filesystem lay-
out, and miscellaneous other things.
8 System management commands
Commands like mount(8), many of which only root can execute.
Macro package
New manual pages should be marked up using the groff an.tmac package de-
scribed in man(7). This choice is mainly for consistency: the vast ma-
jority of existing Linux manual pages are marked up using these macros.
Conventions for source file layout
Please limit source code line length to no more than about 75 characters
wherever possible. This helps avoid line-wrapping in some mail clients
when patches are submitted inline.
Title line
The first command in a man page should be a TH command:
.TH title section date source manual-section
The arguments of the command are as follows:
title The title of the man page, written in all caps (e.g., MAN-PAGES).
section
The section number in which the man page should be placed (e.g.,
7).
date The date of the last nontrivial change that was made to the man
page. (Within the man-pages project, the necessary updates to
these timestamps are handled automatically by scripts, so there
is no need to manually update them as part of a patch.) Dates
should be written in the form YYYY-MM-DD.
source The name and version of the project that provides the manual page
(not necessarily the package that provides the functionality).
manual-section
Normally, this should be empty, since the default value will be
good.
Sections within a manual page
The list below shows conventional or suggested sections. Most manual
pages should include at least the highlighted sections. Arrange a new
manual page so that sections are placed in the order shown in the list.
NAME
LIBRARY [Normally only in Sections 2, 3]
SYNOPSIS
CONFIGURATION [Normally only in Section 4]
DESCRIPTION
OPTIONS [Normally only in Sections 1, 8]
EXIT STATUS [Normally only in Sections 1, 8]
RETURN VALUE [Normally only in Sections 2, 3]
ERRORS [Typically only in Sections 2, 3]
ENVIRONMENT
FILES
ATTRIBUTES [Normally only in Sections 2, 3]
VERSIONS [Normally only in Sections 2, 3]
STANDARDS
HISTORY
NOTES
CAVEATS
BUGS
EXAMPLES
AUTHORS [Discouraged]
REPORTING BUGS [Not used in man-pages]
COPYRIGHT [Not used in man-pages]
SEE ALSO
Where a traditional heading would apply, please use it; this kind of
consistency can make the information easier to understand. If you must,
you can create your own headings if they make things easier to under-
stand (this can be especially useful for pages in Sections 4 and 5).
However, before doing this, consider whether you could use the tradi-
tional headings, with some subsections (.SS) within those sections.
The following list elaborates on the contents of each of the above sec-
tions.
NAME The name of this manual page.
See man(7) for important details of the line(s) that should fol-
low the .SH NAME command. All words in this line (including the
word immediately following the "\-") should be in lowercase, ex-
cept where English or technical terminological convention dic-
tates otherwise.
LIBRARY
The library providing a symbol.
It shows the common name of the library, and in parentheses, the
name of the library file and, if needed, the linker flag needed
to link a program against it: (libfoo[, -lfoo]).
SYNOPSIS
A brief summary of the command or function's interface.
For commands, this shows the syntax of the command and its argu-
ments (including options); boldface is used for as-is text and
italics are used to indicate replaceable arguments. Brackets
([]) surround optional arguments, vertical bars (|) separate
choices, and ellipses (...) can be repeated. For functions, it
shows any required data declarations or #include directives, fol-
lowed by the function declaration.
Where a feature test macro must be defined in order to obtain the
declaration of a function (or a variable) from a header file,
then the SYNOPSIS should indicate this, as described in fea-
ture_test_macros(7).
CONFIGURATION
Configuration details for a device.
This section normally appears only in Section 4 pages.
DESCRIPTION
An explanation of what the program, function, or format does.
Discuss how it interacts with files and standard input, and what
it produces on standard output or standard error. Omit internals
and implementation details unless they're critical for under-
standing the interface. Describe the usual case; for information
on command-line options of a program use the OPTIONS section.
When describing new behavior or new flags for a system call or
library function, be careful to note the kernel or C library ver-
sion that introduced the change. The preferred method of noting
this information for flags is as part of a .TP list, in the fol-
lowing form (here, for a new system call flag):
XYZ_FLAG (since Linux 3.7)
Description of flag...
Including version information is especially useful to users who
are constrained to using older kernel or C library versions
(which is typical in embedded systems, for example).
OPTIONS
A description of the command-line options accepted by a program
and how they change its behavior.
This section should appear only for Section 1 and 8 manual pages.
EXIT STATUS
A list of the possible exit status values of a program and the
conditions that cause these values to be returned.
This section should appear only for Section 1 and 8 manual pages.
RETURN VALUE
For Section 2 and 3 pages, this section gives a list of the val-
ues the library routine will return to the caller and the condi-
tions that cause these values to be returned.
ERRORS For Section 2 and 3 manual pages, this is a list of the values
that may be placed in errno in the event of an error, along with
information about the cause of the errors.
Where several different conditions produce the same error, the
preferred approach is to create separate list entries (with du-
plicate error names) for each of the conditions. This makes the
separate conditions clear, may make the list easier to read, and
allows metainformation (e.g., kernel version number where the
condition first became applicable) to be more easily marked for
each condition.
The error list should be in alphabetical order.
ENVIRONMENT
A list of all environment variables that affect the program or
function and how they affect it.
FILES A list of the files the program or function uses, such as config-
uration files, startup files, and files the program directly op-
erates on.
Give the full pathname of these files, and use the installation
process to modify the directory part to match user preferences.
For many programs, the default installation location is in
/usr/local, so your base manual page should use /usr/local as the
base.
ATTRIBUTES
A summary of various attributes of the function(s) documented on
this page. See attributes(7) for further details.
VERSIONS
A summary of systems where the API performs differently, or where
there's a similar API.
STANDARDS
A description of any standards or conventions that relate to the
function or command described by the manual page.
The preferred terms to use for the various standards are listed
as headings in standards(7).
This section should note the current standards to which the API
conforms to.
If the API is not governed by any standards but commonly exists
on other systems, note them. If the call is Linux-specific or
GNU-specific, note this. If it's available in the BSDs, note
that.
If this section consists of just a list of standards (which it
commonly does), terminate the list with a period ('.').
HISTORY
A brief summary of the Linux kernel or glibc versions where a
system call or library function appeared, or changed signifi-
cantly in its operation.
As a general rule, every new interface should include a HISTORY
section in its manual page. Unfortunately, many existing manual
pages don't include this information (since there was no policy
to do so when they were written). Patches to remedy this are
welcome, but, from the perspective of programmers writing new
code, this information probably matters only in the case of ker-
nel interfaces that have been added in Linux 2.4 or later (i.e.,
changes since Linux 2.2), and library functions that have been
added to glibc since glibc 2.1 (i.e., changes since glibc 2.0).
The syscalls(2) manual page also provides information about ker-
nel versions in which various system calls first appeared.
Old versions of standards should be mentioned here, rather than in STAN-
DARDS, for example, SUS, SUSv2, and XPG, or the SVr4 and 4.xBSD imple-
mentation standards.
NOTES Miscellaneous notes.
For Section 2 and 3 man pages you may find it useful to include
subsections (SS) named Linux Notes and glibc Notes.
In Section 2, use the heading C library/kernel differences to
mark off notes that describe the differences (if any) between the
C library wrapper function for a system call and the raw system
call interface provided by the kernel.
CAVEATS
Warnings about typical user misuse of an API, that don't consti-
tute an API bug or design defect.
BUGS A list of limitations, known defects or inconveniences, and other
questionable activities.
EXAMPLES
One or more examples demonstrating how this function, file, or
command is used.
For details on writing example programs, see Example programs be-
low.
AUTHORS
A list of authors of the documentation or program.
Use of an AUTHORS section is strongly discouraged. Generally, it
is better not to clutter every page with a list of (over time po-
tentially numerous) authors; if you write or significantly amend
a page, add a copyright notice as a comment in the source file.
If you are the author of a device driver and want to include an
address for reporting bugs, place this under the BUGS section.
REPORTING BUGS
The man-pages project doesn't use a REPORTING BUGS section in
manual pages. Information on reporting bugs is instead supplied
in the script-generated COLOPHON section. However, various
projects do use a REPORTING BUGS section. It is recommended to
place it near the foot of the page.
COPYRIGHT
The man-pages project doesn't use a COPYRIGHT section in manual
pages. Copyright information is instead maintained in the page
source. In pages where this section is present, it is recom-
mended to place it near the foot of the page, just above SEE
ALSO.
SEE ALSO
A comma-separated list of related man pages, possibly followed by
other related pages or documents.
The list should be ordered by section number and then alphabeti-
cally by name. Do not terminate this list with a period.
Where the SEE ALSO list contains many long manual page names, to
improve the visual result of the output, it may be useful to em-
ploy the .ad l (don't right justify) and .nh (don't hyphenate)
directives. Hyphenation of individual page names can be pre-
vented by preceding words with the string "\%".
Given the distributed, autonomous nature of FOSS projects and
their documentation, it is sometimes necessary—and in many cases
desirable—that the SEE ALSO section includes references to manual
pages provided by other projects.
FORMATTING AND WORDING CONVENTIONS
The following subsections note some details for preferred formatting and
wording conventions in various sections of the pages in the man-pages
project.
SYNOPSIS
Wrap the function prototype(s) in a .nf/.fi pair to prevent filling.
In general, where more than one function prototype is shown in the SYN-
OPSIS, the prototypes should not be separated by blank lines. However,
blank lines (achieved using .P) may be added in the following cases:
• to separate long lists of function prototypes into related groups
(see for example list(3));
• in other cases that may improve readability.
In the SYNOPSIS, a long function prototype may need to be continued over
to the next line. The continuation line is indented according to the
following rules:
(1) If there is a single such prototype that needs to be continued,
then align the continuation line so that when the page is rendered
on a fixed-width font device (e.g., on an xterm) the continuation
line starts just below the start of the argument list in the line
above. (Exception: the indentation may be adjusted if necessary to
prevent a very long continuation line or a further continuation
line where the function prototype is very long.) As an example:
int tcsetattr(int fd, int optional_actions,
const struct termios *termios_p);
(2) But, where multiple functions in the SYNOPSIS require continuation
lines, and the function names have different lengths, then align
all continuation lines to start in the same column. This provides
a nicer rendering in PDF output (because the SYNOPSIS uses a vari-
able width font where spaces render narrower than most characters).
As an example:
int getopt(int argc, char * const argv[],
const char *optstring);
int getopt_long(int argc, char * const argv[],
const char *optstring,
const struct option *longopts, int *longindex);
RETURN VALUE
The preferred wording to describe how errno is set is "errno is set to
indicate the error" or similar. This wording is consistent with the
wording used in both POSIX.1 and FreeBSD.
ATTRIBUTES
Note the following:
• Wrap the table in this section in a .ad l/.ad pair to disable text
filling and a .nh/.hy pair to disable hyphenation.
• Ensure that the table occupies the full page width through the use of
an lbx description for one of the columns (usually the first column,
though in some cases the last column if it contains a lot of text).
• Make free use of T{/T} macro pairs to allow table cells to be broken
over multiple lines (also bearing in mind that pages may sometimes be
rendered to a width of less than 80 columns).
For examples of all of the above, see the source code of various pages.
STYLE GUIDE
The following subsections describe the preferred style for the man-pages
project. For details not covered below, the Chicago Manual of Style is
usually a good source; try also grepping for preexisting usage in the
project source tree.
Use of gender-neutral language
As far as possible, use gender-neutral language in the text of man
pages. Use of "they" ("them", "themself", "their") as a gender-neutral
singular pronoun is acceptable.
Formatting conventions for manual pages describing commands
For manual pages that describe a command (typically in Sections 1 and
8), the arguments are always specified using italics, even in the SYNOP-
SIS section.
The name of the command, and its options, should always be formatted in
bold.
Formatting conventions for manual pages describing functions
For manual pages that describe functions (typically in Sections 2 and
3), the arguments are always specified using italics, even in the SYNOP-
SIS section, where the rest of the function is specified in bold:
int myfunction(int argc, char **argv);
Variable names should, like argument names, be specified in italics.
Any reference to the subject of the current manual page should be writ-
ten with the name in bold followed by a pair of parentheses in Roman
(normal) font. For example, in the fcntl(2) man page, references to the
subject of the page would be written as: fcntl(). The preferred way to
write this in the source file is:
.BR fcntl ()
(Using this format, rather than the use of "\fB...\fP()" makes it easier
to write tools that parse man page source files.)
Use semantic newlines
In the source of a manual page, new sentences should be started on new
lines, long sentences should be split into lines at clause breaks (com-
mas, semicolons, colons, and so on), and long clauses should be split at
phrase boundaries. This convention, sometimes known as "semantic new-
lines", makes it easier to see the effect of patches, which often oper-
ate at the level of individual sentences, clauses, or phrases.
Lists
There are different kinds of lists:
Tagged paragraphs
These are used for a list of tags and their descriptions. When
the tags are constants (either macros or numbers) they are in
bold. Use the .TP macro.
An example is this "Tagged paragraphs" subsection is itself.
Ordered lists
Elements are preceded by a number in parentheses (1), (2). These
represent a set of steps that have an order.
When there are substeps, they will be numbered like (4.2).
Positional lists
Elements are preceded by a number (index) in square brackets [4],
[5]. These represent fields in a set. The first index will be:
0 When it represents fields of a C data structure, to be
consistent with arrays.
1 When it represents fields of a file, to be consistent with
tools like cut(1).
Alternatives list
Elements are preceded by a letter in parentheses (a), (b). These
represent a set of (normally) exclusive alternatives.
Bullet lists
Elements are preceded by bullet symbols (\[bu]). Anything that
doesn't fit elsewhere is usually covered by this type of list.
Numbered notes
Not really a list, but the syntax is identical to "positional
lists".
There should always be exactly 2 spaces between the list symbol and the
elements. This doesn't apply to "tagged paragraphs", which use the de-
fault indentation rules.
Formatting conventions (general)
Paragraphs should be separated by suitable markers (usually either .P or
.IP). Do not separate paragraphs using blank lines, as this results in
poor rendering in some output formats (such as PostScript and PDF).
Filenames (whether pathnames, or references to header files) are always
in italics (e.g., <stdio.h>), except in the SYNOPSIS section, where in-
cluded files are in bold (e.g., #include <stdio.h>). When referring to
a standard header file include, specify the header file surrounded by
angle brackets, in the usual C way (e.g., <stdio.h>).
Special macros, which are usually in uppercase, are in bold (e.g., MAX-
INT). Exception: don't boldface NULL.
When enumerating a list of error codes, the codes are in bold (this list
usually uses the .TP macro).
Complete commands should, if long, be written as an indented line on
their own, with a blank line before and after the command, for example
man 7 man-pages
If the command is short, then it can be included inline in the text, in
italic format, for example, man 7 man-pages. In this case, it may be
worth using nonbreaking spaces (\~) at suitable places in the command.
Command options should be written in italics (e.g., -l).
Expressions, if not written on a separate indented line, should be spec-
ified in italics. Again, the use of nonbreaking spaces may be appropri-
ate if the expression is inlined with normal text.
When showing example shell sessions, user input should be formatted in
bold, for example
$ date
Thu Jul 7 13:01:27 CEST 2016
Any reference to another man page should be written with the name in
bold, always followed by the section number, formatted in Roman (normal)
font, without any separating spaces (e.g., intro(2)). The preferred way
to write this in the source file is:
.BR intro (2)
(Including the section number in cross references lets tools like
man2html(1) create properly hyperlinked pages.)
Control characters should be written in bold face, with no quotes; for
example, ^X.
Spelling
Starting with release 2.59, man-pages follows American spelling conven-
tions (previously, there was a random mix of British and American
spellings); please write all new pages and patches according to these
conventions.
Aside from the well-known spelling differences, there are a few other
subtleties to watch for:
• American English tends to use the forms "backward", "upward", "to-
ward", and so on rather than the British forms "backwards", "up-
wards", "towards", and so on.
• Opinions are divided on "acknowledgement" vs "acknowledgment". The
latter is predominant, but not universal usage in American English.
POSIX and the BSD license use the former spelling. In the Linux man-
pages project, we use "acknowledgement".
BSD version numbers
The classical scheme for writing BSD version numbers is x.yBSD, where
x.y is the version number (e.g., 4.2BSD). Avoid forms such as BSD 4.3.
Capitalization
In subsection ("SS") headings, capitalize the first word in the heading,
but otherwise use lowercase, except where English usage (e.g., proper
nouns) or programming language requirements (e.g., identifier names)
dictate otherwise. For example:
.SS Unicode under Linux
Indentation of structure definitions, shell session logs, and so on
When structure definitions, shell session logs, and so on are included
in running text, indent them by 4 spaces (i.e., a block enclosed by
.in +4n and .in), format them using the .EX and .EE macros, and surround
them with suitable paragraph markers (either .P or .IP). For example:
.P
.in +4n
.EX
int
main(int argc, char *argv[])
{
return 0;
}
.EE
.in
.P
Preferred terms
The following table lists some preferred terms to use in man pages,
mainly to ensure consistency across pages.
Term Avoid using Notes
────────────────────────────────────────────────────────────────
bit mask bitmask
built-in builtin
Epoch epoch For the UNIX
Epoch (00:00:00,
1 Jan 1970 UTC)
filename file name
filesystem file system
hostname host name
inode i-node
lowercase lower case, lower-case
nonzero non-zero
pathname path name
pseudoterminal pseudo-terminal
privileged port reserved port, system
port
real-time realtime, real time
run time runtime
saved set-group-ID saved group ID, saved
set-GID
saved set-user-ID saved user ID, saved
set-UID
set-group-ID set-GID, setgid
set-user-ID set-UID, setuid
superuser super user, super-user
superblock super block, super-
block
symbolic link symlink
timestamp time stamp
timezone time zone
uppercase upper case, upper-case
usable useable
user space userspace
username user name
x86-64 x86_64 Except if refer-
ring to result
of "uname -m" or
similar
zeros zeroes
See also the discussion Hyphenation of attributive compounds below.
Terms to avoid
The following table lists some terms to avoid using in man pages, along
with some suggested alternatives, mainly to ensure consistency across
pages.
Avoid Use instead Notes
──────────────────────────────────────────────────────────
32bit 32-bit same for 8-bit,
16-bit, etc.
current process calling process A common mistake
made by kernel pro-
grammers when writ-
ing man pages
manpage man page, manual
page
minus infinity negative infinity
non-root unprivileged user
non-superuser unprivileged user
nonprivileged unprivileged
OS operating system
plus infinity positive infinity
pty pseudoterminal
tty terminal
Unices UNIX systems
Unixes UNIX systems
Trademarks
Use the correct spelling and case for trademarks. The following is a
list of the correct spellings of various relevant trademarks that are
sometimes misspelled:
DG/UX
HP-UX
UNIX
UnixWare
NULL, NUL, null pointer, and null byte
A null pointer is a pointer that points to nothing, and is normally in-
dicated by the constant NULL. On the other hand, NUL is the null byte,
a byte with the value 0, represented in C via the character constant
'\0'.
The preferred term for the pointer is "null pointer" or simply "NULL";
avoid writing "NULL pointer".
The preferred term for the byte is "null byte". Avoid writing "NUL",
since it is too easily confused with "NULL". Avoid also the terms "zero
byte" and "null character". The byte that terminates a C string should
be described as "the terminating null byte"; strings may be described as
"null-terminated", but avoid the use of "NUL-terminated".
Hyperlinks
For hyperlinks, use the .UR/.UE macro pair (see groff_man(7)). This
produces proper hyperlinks that can be used in a web browser, when ren-
dering a page with, say:
BROWSER=firefox man -H pagename
Use of e.g., i.e., etc., a.k.a., and similar
In general, the use of abbreviations such as "e.g.", "i.e.", "etc.",
"cf.", and "a.k.a." should be avoided, in favor of suitable full word-
ings ("for example", "that is", "and so on", "compare to", "also known
as").
The only place where such abbreviations may be acceptable is in short
parenthetical asides (e.g., like this one).
Always include periods in such abbreviations, as shown here. In addi-
tion, "e.g." and "i.e." should always be followed by a comma.
Em-dashes
The way to write an em-dash—the glyph that appears at either end of this
subphrase—in *roff is with the macro "\[em]". (On an ASCII terminal, an
em-dash typically renders as two hyphens, but in other typographical
contexts it renders as a long dash.) Em-dashes should be written with-
out surrounding spaces.
Hyphenation of attributive compounds
Compound terms should be hyphenated when used attributively (i.e., to
qualify a following noun). Some examples:
32-bit value
command-line argument
floating-point number
run-time check
user-space function
wide-character string
Hyphenation with multi, non, pre, re, sub, and so on
The general tendency in modern English is not to hyphenate after pre-
fixes such as "multi", "non", "pre", "re", "sub", and so on. Manual
pages should generally follow this rule when these prefixes are used in
natural English constructions with simple suffixes. The following list
gives some examples of the preferred forms:
interprocess
multithreaded
multiprocess
nonblocking
nondefault
nonempty
noninteractive
nonnegative
nonportable
nonzero
preallocated
precreate
prerecorded
reestablished
reinitialize
rearm
reread
subcomponent
subdirectory
subsystem
Hyphens should be retained when the prefixes are used in nonstandard
English words, with trademarks, proper nouns, acronyms, or compound
terms. Some examples:
non-ASCII
non-English
non-NULL
non-real-time
Finally, note that "re-create" and "recreate" are two different verbs,
and the former is probably what you want.
Generating optimal glyphs
Where a real minus character is required (e.g., for numbers such as -1,
for man page cross references such as utf-8(7), or when writing options
that have a leading dash, such as in ls -l), use the following form in
the man page source:
\-
This guideline applies also to code examples.
The use of real minus signs serves the following purposes:
• To provide better renderings on various targets other than ASCII ter-
minals, notably in PDF and on Unicode/UTF-8-capable terminals.
• To generate glyphs that when copied from rendered pages will produce
real minus signs when pasted into a terminal.
To produce unslanted single quotes that render well in ASCII, UTF-8, and
PDF, use "\[aq]" ("apostrophe quote"); for example
\[aq]C\[aq]
where C is the quoted character. This guideline applies also to charac-
ter constants used in code examples.
Where a proper caret (^) that renders well in both a terminal and PDF is
required, use "\[ha]". This is especially necessary in code samples, to
get a nicely rendered caret when rendering to PDF.
Using a naked "~" character results in a poor rendering in PDF. Instead
use "\[ti]". This is especially necessary in code samples, to get a
nicely rendered tilde when rendering to PDF.
Example programs and shell sessions
Manual pages may include example programs demonstrating how to use a
system call or library function. However, note the following:
• Example programs should be written in C.
• An example program is necessary and useful only if it demonstrates
something beyond what can easily be provided in a textual description
of the interface. An example program that does nothing other than
call an interface usually serves little purpose.
• Example programs should ideally be short (e.g., a good example can
often be provided in less than 100 lines of code), though in some
cases longer programs may be necessary to properly illustrate the use
of an API.
• Expressive code is appreciated.
• Comments should included where helpful. Complete sentences in free-
standing comments should be terminated by a period. Periods should
generally be omitted in "tag" comments (i.e., comments that are
placed on the same line of code); such comments are in any case typi-
cally brief phrases rather than complete sentences.
• Example programs should do error checking after system calls and li-
brary function calls.
• Example programs should be complete, and compile without warnings
when compiled with cc -Wall.
• Where possible and appropriate, example programs should allow experi-
mentation, by varying their behavior based on inputs (ideally from
command-line arguments, or alternatively, via input read by the pro-
gram).
• Example programs should be laid out according to Kernighan and
Ritchie style, with 4-space indents. (Avoid the use of TAB charac-
ters in source code!) The following command can be used to format
your source code to something close to the preferred style:
indent -npro -kr -i4 -ts4 -sob -l72 -ss -nut -psl prog.c
• For consistency, all example programs should terminate using either
of:
exit(EXIT_SUCCESS);
exit(EXIT_FAILURE);
Avoid using the following forms to terminate a program:
exit(0);
exit(1);
return n;
• If there is extensive explanatory text before the program source
code, mark off the source code with a subsection heading Program
source, as in:
.SS Program source
Always do this if the explanatory text includes a shell session log.
If you include a shell session log demonstrating the use of a program or
other system feature:
• Place the session log above the source code listing.
• Indent the session log by four spaces.
• Boldface the user input text, to distinguish it from output produced
by the system.
For some examples of what example programs should look like, see wait(2)
and pipe(2).
EXAMPLES
For canonical examples of how man pages in the man-pages package should
look, see pipe(2) and fcntl(2).
SEE ALSO
man(1), man2html(1), attributes(7), groff(7), groff_man(7), man(7),
mdoc(7)
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