{ "content": [ { "type": "text", "text": "# MAN-PAGES (info)\n\n## NAME\n\nman-pages - conventions for writing Linux man pages\n\n## SYNOPSIS\n\nman [section] title\n\n## DESCRIPTION\n\nThis page describes the conventions that should be employed when writ-\ning man pages for the Linux man-pages project, which documents the\nuser-space API provided by the Linux kernel and the GNU C library. The\nproject thus provides most of the pages in Section 2, many of the pages\nthat appear in Sections 3, 4, and 7, and a few of the pages that appear\nin Sections 1, 5, and 8 of the man pages on a Linux system. The con-\nventions described on this page may also be useful for authors writing\nman pages for other projects.\n\n## Sections\n\n- **NAME**\n- **SYNOPSIS**\n- **DESCRIPTION**\n- **STYLE GUIDE**\n- **EXAMPLES**\n- **SEE ALSO**\n- **COLOPHON**\n\nUse structuredContent.sections for detailed options, examples, and full documentation.\n" } ], "structuredContent": { "command": "MAN-PAGES", "section": "", "mode": "info", "summary": "man-pages - conventions for writing Linux man pages", "synopsis": "man [section] title", "tldr_summary": null, "tldr_examples": [], "tldr_source": null, "flags": [], "examples": [ "For canonical examples of how man pages in the man-pages package should", "look, see pipe(2) and fcntl(2)." ], "see_also": [ { "name": "man", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/man/1/json" }, { "name": "man2html", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/man2html/1/json" }, { "name": "attributes", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/attributes/7/json" }, { "name": "groff", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/groff/7/json" }, { "name": "groffman", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/groffman/7/json" }, { "name": "man", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/man/7/json" }, { "name": "mdoc", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/mdoc/7/json" } ], "section_outline": [ { "name": "NAME", "lines": 2, "subsections": [] }, { "name": "SYNOPSIS", "lines": 2, "subsections": [] }, { "name": "DESCRIPTION", "lines": 337, "subsections": [] }, { "name": "STYLE GUIDE", "lines": 405, "subsections": [] }, { "name": "EXAMPLES", "lines": 3, "subsections": [] }, { "name": "SEE ALSO", "lines": 3, "subsections": [] }, { "name": "COLOPHON", "lines": 6, "subsections": [] } ], "sections": { "NAME": { "content": "man-pages - conventions for writing Linux man pages\n", "subsections": [] }, "SYNOPSIS": { "content": "man [section] title\n", "subsections": [] }, "DESCRIPTION": { "content": "This page describes the conventions that should be employed when writ-\ning man pages for the Linux man-pages project, which documents the\nuser-space API provided by the Linux kernel and the GNU C library. The\nproject thus provides most of the pages in Section 2, many of the pages\nthat appear in Sections 3, 4, and 7, and a few of the pages that appear\nin Sections 1, 5, and 8 of the man pages on a Linux system. The con-\nventions described on this page may also be useful for authors writing\nman pages for other projects.\n\nSections of the manual pages\nThe manual Sections are traditionally defined as follows:\n\n1 User commands (Programs)\nCommands that can be executed by the user from within a shell.\n\n2 System calls\nFunctions which wrap operations performed by the kernel.\n\n3 Library calls\nAll library functions excluding the system call wrappers (Most\nof the libc functions).\n\n4 Special files (devices)\nFiles found in /dev which allow to access to devices through the\nkernel.\n\n5 File formats and configuration files\nDescribes various human-readable file formats and configuration\nfiles.\n\n6 Games\nGames and funny little programs available on the system.\n\n7 Overview, conventions, and miscellaneous\nOverviews or descriptions of various topics, conventions and\nprotocols, character set standards, the standard filesystem lay-\nout, and miscellaneous other things.\n\n8 System management commands\nCommands like mount(8), many of which only root can execute.\n\nMacro package\nNew manual pages should be marked up using the groff an.tmac package\ndescribed in man(7). This choice is mainly for consistency: the vast\nmajority of existing Linux manual pages are marked up using these\nmacros.\n\nConventions for source file layout\nPlease limit source code line length to no more than about 75 charac-\nters wherever possible. This helps avoid line-wrapping in some mail\nclients when patches are submitted inline.\n\nTitle line\nThe first command in a man page should be a TH command:\n\n.TH title section date source manual\n\nThe arguments of the command are as follows:\n\ntitle The title of the man page, written in all caps (e.g., MAN-\nPAGES).\n\nsection\nThe section number in which the man page should be placed (e.g.,\n7).\n\ndate The date of the last nontrivial change that was made to the man\npage. (Within the man-pages project, the necessary updates to\nthese timestamps are handled automatically by scripts, so there\nis no need to manually update them as part of a patch.) Dates\nshould be written in the form YYYY-MM-DD.\n\nsource The source of the command, function, or system call.\n\nFor those few man-pages pages in Sections 1 and 8, probably you\njust want to write GNU.\n\nFor system calls, just write Linux. (An earlier practice was to\nwrite the version number of the kernel from which the manual\npage was being written/checked. However, this was never done\nconsistently, and so was probably worse than including no ver-\nsion number. Henceforth, avoid including a version number.)\n\nFor library calls that are part of glibc or one of the other\ncommon GNU libraries, just use GNU C Library, GNU, or an empty\nstring.\n\nFor Section 4 pages, use Linux.\n\nIn cases of doubt, just write Linux, or GNU.\n\nmanual The title of the manual (e.g., for Section 2 and 3 pages in the\nman-pages package, use Linux Programmer's Manual).\n\nSections within a manual page\nThe list below shows conventional or suggested sections. Most manual\npages should include at least the highlighted sections. Arrange a new\nmanual page so that sections are placed in the order shown in the list.\n\nNAME\nSYNOPSIS\nCONFIGURATION [Normally only in Section 4]\nDESCRIPTION\nOPTIONS [Normally only in Sections 1, 8]\nEXIT STATUS [Normally only in Sections 1, 8]\nRETURN VALUE [Normally only in Sections 2, 3]\nERRORS [Typically only in Sections 2, 3]\nENVIRONMENT\nFILES\nVERSIONS [Normally only in Sections 2, 3]\nATTRIBUTES [Normally only in Sections 2, 3]\nCONFORMING TO\nNOTES\nBUGS\nEXAMPLES\nAUTHORS [Discouraged]\nREPORTING BUGS [Not used in man-pages]\nCOPYRIGHT [Not used in man-pages]\nSEE ALSO\n\nWhere a traditional heading would apply, please use it; this kind of\nconsistency can make the information easier to understand. If you\nmust, you can create your own headings if they make things easier to\nunderstand (this can be especially useful for pages in Sections 4 and\n5). However, before doing this, consider whether you could use the\ntraditional headings, with some subsections (.SS) within those sec-\ntions.\n\nThe following list elaborates on the contents of each of the above sec-\ntions.\n\nNAME The name of this manual page.\n\nSee man(7) for important details of the line(s) that should fol-\nlow the .SH NAME command. All words in this line (including the\nword immediately following the \"\\-\") should be in lowercase, ex-\ncept where English or technical terminological convention dic-\ntates otherwise.\n\nSYNOPSIS\nA brief summary of the command or function's interface.\n\nFor commands, this shows the syntax of the command and its argu-\nments (including options); boldface is used for as-is text and\nitalics are used to indicate replaceable arguments. Brackets\n([]) surround optional arguments, vertical bars (|) separate\nchoices, and ellipses (...) can be repeated. For functions, it\nshows any required data declarations or #include directives,\nfollowed by the function declaration.\n\nWhere a feature test macro must be defined in order to obtain\nthe declaration of a function (or a variable) from a header\nfile, then the SYNOPSIS should indicate this, as described in\nfeaturetestmacros(7).\n\nCONFIGURATION\nConfiguration details for a device.\n\nThis section normally appears only in Section 4 pages.\n\nDESCRIPTION\nAn explanation of what the program, function, or format does.\n\nDiscuss how it interacts with files and standard input, and what\nit produces on standard output or standard error. Omit inter-\nnals and implementation details unless they're critical for un-\nderstanding the interface. Describe the usual case; for infor-\nmation on command-line options of a program use the OPTIONS sec-\ntion.\n\nWhen describing new behavior or new flags for a system call or\nlibrary function, be careful to note the kernel or C library\nversion that introduced the change. The preferred method of\nnoting this information for flags is as part of a .TP list, in\nthe following form (here, for a new system call flag):\n\nXYZFLAG (since Linux 3.7)\nDescription of flag...\n\nIncluding version information is especially useful to users who\nare constrained to using older kernel or C library versions\n(which is typical in embedded systems, for example).\n\nOPTIONS\nA description of the command-line options accepted by a program\nand how they change its behavior.\n\nThis section should appear only for Section 1 and 8 manual\npages.\n\nEXIT STATUS\nA list of the possible exit status values of a program and the\nconditions that cause these values to be returned.\n\nThis section should appear only for Section 1 and 8 manual\npages.\n\nRETURN VALUE\nFor Section 2 and 3 pages, this section gives a list of the val-\nues the library routine will return to the caller and the condi-\ntions that cause these values to be returned.\n\nERRORS For Section 2 and 3 manual pages, this is a list of the values\nthat may be placed in errno in the event of an error, along with\ninformation about the cause of the errors.\n\nWhere several different conditions produce the same error, the\npreferred approach is to create separate list entries (with du-\nplicate error names) for each of the conditions. This makes the\nseparate conditions clear, may make the list easier to read, and\nallows metainformation (e.g., kernel version number where the\ncondition first became applicable) to be more easily marked for\neach condition.\n\nThe error list should be in alphabetical order.\n\nENVIRONMENT\nA list of all environment variables that affect the program or\nfunction and how they affect it.\n\nFILES A list of the files the program or function uses, such as con-\nfiguration files, startup files, and files the program directly\noperates on.\n\nGive the full pathname of these files, and use the installation\nprocess to modify the directory part to match user preferences.\nFor many programs, the default installation location is in\n/usr/local, so your base manual page should use /usr/local as\nthe base.\n\nATTRIBUTES\nA summary of various attributes of the function(s) documented on\nthis page. See attributes(7) for further details.\n\nVERSIONS\nA brief summary of the Linux kernel or glibc versions where a\nsystem call or library function appeared, or changed signifi-\ncantly in its operation.\n\nAs a general rule, every new interface should include a VERSIONS\nsection in its manual page. Unfortunately, many existing manual\npages don't include this information (since there was no policy\nto do so when they were written). Patches to remedy this are\nwelcome, but, from the perspective of programmers writing new\ncode, this information probably matters only in the case of ker-\nnel interfaces that have been added in Linux 2.4 or later (i.e.,\nchanges since kernel 2.2), and library functions that have been\nadded to glibc since version 2.1 (i.e., changes since glibc\n2.0).\n\nThe syscalls(2) manual page also provides information about ker-\nnel versions in which various system calls first appeared.\n\nCONFORMING TO\nA description of any standards or conventions that relate to the\nfunction or command described by the manual page.\n\nThe preferred terms to use for the various standards are listed\nas headings in standards(7).\n\nFor a page in Section 2 or 3, this section should note the\nPOSIX.1 version(s) that the call conforms to, and also whether\nthe call is specified in C99. (Don't worry too much about other\nstandards like SUS, SUSv2, and XPG, or the SVr4 and 4.xBSD im-\nplementation standards, unless the call was specified in those\nstandards, but isn't in the current version of POSIX.1.)\n\nIf the call is not governed by any standards but commonly exists\non other systems, note them. If the call is Linux-specific,\nnote this.\n\nIf this section consists of just a list of standards (which it\ncommonly does), terminate the list with a period ('.').\n\nNOTES Miscellaneous notes.\n\nFor Section 2 and 3 man pages you may find it useful to include\nsubsections (SS) named Linux Notes and Glibc Notes.\n\nIn Section 2, use the heading C library/kernel differences to\nmark off notes that describe the differences (if any) between\nthe C library wrapper function for a system call and the raw\nsystem call interface provided by the kernel.\n\nBUGS A list of limitations, known defects or inconveniences, and\nother questionable activities.\n\nEXAMPLES\nOne or more examples demonstrating how this function, file or\ncommand is used.\n\nFor details on writing example programs, see Example programs\nbelow.\n\nAUTHORS\nA list of authors of the documentation or program.\n\nUse of an AUTHORS section is strongly discouraged. Generally,\nit is better not to clutter every page with a list of (over time\npotentially numerous) authors; if you write or significantly\namend a page, add a copyright notice as a comment in the source\nfile. If you are the author of a device driver and want to in-\nclude an address for reporting bugs, place this under the BUGS\nsection.\n\nREPORTING BUGS\nThe man-pages project doesn't use a REPORTING BUGS section in\nmanual pages. Information on reporting bugs is instead supplied\nin the script-generated COLOPHON section. However, various\nprojects do use a REPORTING BUGS section. it is recommended to\nplace it near the foot of the page.\n\nCOPYRIGHT\nThe man-pages project doesn't use a COPYRIGHT section in manual\npages. Copyright information is instead maintained in the page\nsource. In pages where this section is present, it is recom-\nmended to place it near the foot of the page, just above SEE\nALSO.\n\nSEE ALSO\nA comma-separated list of related man pages, possibly followed\nby other related pages or documents.\n\nThe list should be ordered by section number and then alphabeti-\ncally by name. Do not terminate this list with a period.\n\nWhere the SEE ALSO list contains many long manual page names, to\nimprove the visual result of the output, it may be useful to em-\nploy the .ad l (don't right justify) and .nh (don't hyphenate)\ndirectives. Hyphenation of individual page names can be pre-\nvented by preceding words with the string \"\\%\".\n\nGiven the distributed, autonomous nature of FOSS projects and\ntheir documentation, it is sometimes necessary--and in many\ncases desirable--that the SEE ALSO section includes references\nto manual pages provided by other projects.\n", "subsections": [] }, "STYLE GUIDE": { "content": "The following subsections describe the preferred style for the man-\npages project. For details not covered below, the Chicago Manual of\nStyle is usually a good source; try also grepping for preexisting usage\nin the project source tree.\n\nUse of gender-neutral language\nAs far as possible, use gender-neutral language in the text of man\npages. Use of \"they\" (\"them\", \"themself\", \"their\") as a gender-neutral\nsingular pronoun is acceptable.\n\nFormatting conventions for manual pages describing commands\nFor manual pages that describe a command (typically in Sections 1 and\n8), the arguments are always specified using italics, even in the SYN-\nOPSIS section.\n\nThe name of the command, and its options, should always be formatted in\nbold.\n\nFormatting conventions for manual pages describing functions\nFor manual pages that describe functions (typically in Sections 2 and\n3), the arguments are always specified using italics, even in the SYN-\nOPSIS section, where the rest of the function is specified in bold:\n\nint myfunction(int argc, char argv);\n\nVariable names should, like argument names, be specified in italics.\n\nAny reference to the subject of the current manual page should be writ-\nten with the name in bold followed by a pair of parentheses in Roman\n(normal) font. For example, in the fcntl(2) man page, references to\nthe subject of the page would be written as: fcntl(). The preferred\nway to write this in the source file is:\n\n.BR fcntl ()\n\n(Using this format, rather than the use of \"\\fB...\\fP()\" makes it eas-\nier to write tools that parse man page source files.)\n\nUse semantic newlines\nIn the source of a manual page, new sentences should be started on new\nlines, and long sentences should split into lines at clause breaks\n(commas, semicolons, colons, and so on). This convention, sometimes\nknown as \"semantic newlines\", makes it easier to see the effect of\npatches, which often operate at the level of individual sentences or\nsentence clauses.\n\nFormatting conventions (general)\nParagraphs should be separated by suitable markers (usually either .PP\nor .IP). Do not separate paragraphs using blank lines, as this results\nin poor rendering in some output formats (such as PostScript and PDF).\n\nFilenames (whether pathnames, or references to header files) are always\nin italics (e.g., ), except in the SYNOPSIS section, where in-\ncluded files are in bold (e.g., #include ). When referring to\na standard header file include, specify the header file surrounded by\nangle brackets, in the usual C way (e.g., ).\n\nSpecial macros, which are usually in uppercase, are in bold (e.g., MAX-\nINT). Exception: don't boldface NULL.\n\nWhen enumerating a list of error codes, the codes are in bold (this\nlist usually uses the .TP macro).\n\nComplete commands should, if long, be written as an indented line on\ntheir own, with a blank line before and after the command, for example\n\nman 7 man-pages\n\nIf the command is short, then it can be included inline in the text, in\nitalic format, for example, man 7 man-pages. In this case, it may be\nworth using nonbreaking spaces (\"\\ \") at suitable places in the com-\nmand. Command options should be written in italics (e.g., -l).\n\nExpressions, if not written on a separate indented line, should be\nspecified in italics. Again, the use of nonbreaking spaces may be ap-\npropriate if the expression is inlined with normal text.\n\nWhen showing example shell sessions, user input should be formatted in\nbold, for example\n\n$ date\nThu Jul 7 13:01:27 CEST 2016\n\nAny reference to another man page should be written with the name in\nbold, always followed by the section number, formatted in Roman (nor-\nmal) font, without any separating spaces (e.g., intro(2)). The pre-\nferred way to write this in the source file is:\n\n.BR intro (2)\n\n(Including the section number in cross references lets tools like\nman2html(1) create properly hyperlinked pages.)\n\nControl characters should be written in bold face, with no quotes; for\nexample, ^X.\n\nSpelling\nStarting with release 2.59, man-pages follows American spelling conven-\ntions (previously, there was a random mix of British and American\nspellings); please write all new pages and patches according to these\nconventions.\n\nAside from the well-known spelling differences, there are a few other\nsubtleties to watch for:\n\n* American English tends to use the forms \"backward\", \"upward\", \"to-\nward\", and so on rather than the British forms \"backwards\", \"up-\nwards\", \"towards\", and so on.\n\nBSD version numbers\nThe classical scheme for writing BSD version numbers is x.yBSD, where\nx.y is the version number (e.g., 4.2BSD). Avoid forms such as BSD 4.3.\n\nCapitalization\nIn subsection (\"SS\") headings, capitalize the first word in the head-\ning, but otherwise use lowercase, except where English usage (e.g.,\nproper nouns) or programming language requirements (e.g., identifier\nnames) dictate otherwise. For example:\n\n.SS Unicode under Linux\n\nIndentation of structure definitions, shell session logs, and so on\nWhen structure definitions, shell session logs, and so on are included\nin running text, indent them by 4 spaces (i.e., a block enclosed by\n.in +4n and .in), format them using the .EX and EE macros, and surround\nthem with suitable paragraph markers (either .PP or .IP). For example:\n\n.PP\n.in +4n\n.EX\nint\nmain(int argc, char *argv[])\n{\nreturn 0;\n}\n.EE\n.in\n.PP\n\nPreferred terms\nThe following table lists some preferred terms to use in man pages,\nmainly to ensure consistency across pages.\n\n\nbit mask bitmask\nbuilt-in builtin\nEpoch epoch For the UNIX Epoch\n(00:00:00, 1 Jan\n1970 UTC)\nfilename file name\nfilesystem file system\nhostname host name\ninode i-node\nlowercase lower case, lower-case\nnonzero non-zero\npathname path name\npseudoterminal pseudo-terminal\nprivileged port reserved port, system\nport\nreal-time realtime, real time\nrun time runtime\nsaved set-group-ID saved group ID, saved\nset-GID\nsaved set-user-ID saved user ID, saved\nset-UID\nset-group-ID set-GID, setgid\nset-user-ID set-UID, setuid\nsuperuser super user, super-user\nsuperblock super block, super-\nblock\ntimestamp time stamp\ntimezone time zone\nuppercase upper case, upper-case\nusable useable\nuser space userspace\nusername user name\nx86-64 x8664 Except if referring\nto result of \"un-\name -m\" or similar\nzeros zeroes\n\nSee also the discussion Hyphenation of attributive compounds below.\n\nTerms to avoid\nThe following table lists some terms to avoid using in man pages, along\nwith some suggested alternatives, mainly to ensure consistency across\npages.\n\n\n32bit 32-bit same for 8-bit,\n16-bit, etc.\ncurrent process calling process A common mistake\nmade by kernel pro-\ngrammers when writ-\ning man pages\nmanpage man page, manual\npage\nminus infinity negative infinity\nnon-root unprivileged user\nnon-superuser unprivileged user\nnonprivileged unprivileged\nOS operating system\nplus infinity positive infinity\npty pseudoterminal\ntty terminal\nUnices UNIX systems\nUnixes UNIX systems\n\nTrademarks\nUse the correct spelling and case for trademarks. The following is a\nlist of the correct spellings of various relevant trademarks that are\nsometimes misspelled:\n\nDG/UX\nHP-UX\nUNIX\nUnixWare\n\nNULL, NUL, null pointer, and null character\nA null pointer is a pointer that points to nothing, and is normally in-\ndicated by the constant NULL. On the other hand, NUL is the null byte,\na byte with the value 0, represented in C via the character constant\n'\\0'.\n\nThe preferred term for the pointer is \"null pointer\" or simply \"NULL\";\navoid writing \"NULL pointer\".\n\nThe preferred term for the byte is \"null byte\". Avoid writing \"NUL\",\nsince it is too easily confused with \"NULL\". Avoid also the terms\n\"zero byte\" and \"null character\". The byte that terminates a C string\nshould be described as \"the terminating null byte\"; strings may be de-\nscribed as \"null-terminated\", but avoid the use of \"NUL-terminated\".\n\nHyperlinks\nFor hyperlinks, use the .UR/.UE macro pair (see groffman(7)). This\nproduces proper hyperlinks that can be used in a web browser, when ren-\ndering a page with, say:\n\nBROWSER=firefox man -H pagename\n\nUse of e.g., i.e., etc., a.k.a., and similar\nIn general, the use of abbreviations such as \"e.g.\", \"i.e.\", \"etc.\",\n\"cf.\", and \"a.k.a.\" should be avoided, in favor of suitable full word-\nings (\"for example\", \"that is\", \"and so on\", \"compare to\", \"also known\nas\").\n\nThe only place where such abbreviations may be acceptable is in short\nparenthetical asides (e.g., like this one).\n\nAlways include periods in such abbreviations, as shown here. In addi-\ntion, \"e.g.\" and \"i.e.\" should always be followed by a comma.\n\nEm-dashes\nThe way to write an em-dash--the glyph that appears at either end of\nthis subphrase--in *roff is with the macro \"\\(em\". (On an ASCII termi-\nnal, an em-dash typically renders as two hyphens, but in other typo-\ngraphical contexts it renders as a long dash.) Em-dashes should be\nwritten without surrounding spaces.\n\nHyphenation of attributive compounds\nCompound terms should be hyphenated when used attributively (i.e., to\nqualify a following noun). Some examples:\n\n32-bit value\ncommand-line argument\nfloating-point number\nrun-time check\nuser-space function\nwide-character string\n\nHyphenation with multi, non, pre, re, sub, and so on\nThe general tendency in modern English is not to hyphenate after pre-\nfixes such as \"multi\", \"non\", \"pre\", \"re\", \"sub\", and so on. Manual\npages should generally follow this rule when these prefixes are used in\nnatural English constructions with simple suffixes. The following list\ngives some examples of the preferred forms:\n\ninterprocess\nmultithreaded\nmultiprocess\nnonblocking\nnondefault\nnonempty\nnoninteractive\nnonnegative\nnonportable\nnonzero\npreallocated\nprecreate\nprerecorded\nreestablished\nreinitialize\nrearm\nreread\nsubcomponent\nsubdirectory\nsubsystem\n\nHyphens should be retained when the prefixes are used in nonstandard\nEnglish words, with trademarks, proper nouns, acronyms, or compound\nterms. Some examples:\n\nnon-ASCII\nnon-English\nnon-NULL\nnon-real-time\n\nFinally, note that \"re-create\" and \"recreate\" are two different verbs,\nand the former is probably what you want.\n\nGenerating optimal glyphs\nWhere a real minus character is required (e.g., for numbers such as -1,\nfor man page cross references such as utf-8(7), or when writing options\nthat have a leading dash, such as in ls -l), use the following form in\nthe man page source:\n\n\\-\n\nThis guideline applies also to code examples.\n\nTo produce unslanted single quotes that render well in ASCII, UTF-8,\nand PDF, use \"\\(aq\" (\"apostrophe quote\"); for example\n\n\\(aqC\\(aq\n\nwhere C is the quoted character. This guideline applies also to char-\nacter constants used in code examples.\n\nWhere a proper caret (^) that renders well in both a terminal and PDF\nis required, use \"\\(ha\". This is especially necessary in code samples,\nto get a nicely rendered caret when rendering to PDF.\n\nUsing a naked \"~\" character results in a poor rendering in PDF. In-\nstead use \"\\(ti\". This is especially necessary in code samples, to get\na nicely rendered tilde when rendering to PDF.\n\nExample programs and shell sessions\nManual pages may include example programs demonstrating how to use a\nsystem call or library function. However, note the following:\n\n* Example programs should be written in C.\n\n* An example program is necessary and useful only if it demonstrates\nsomething beyond what can easily be provided in a textual descrip-\ntion of the interface. An example program that does nothing other\nthan call an interface usually serves little purpose.\n\n* Example programs should ideally be short (e.g., a good example can\noften be provided in less than 100 lines of code), though in some\ncases longer programs may be necessary to properly illustrate the\nuse of an API.\n\n* Expressive code and useful comments are appreciated.\n\n* Example programs should do error checking after system calls and li-\nbrary function calls.\n\n* Example programs should be complete, and compile without warnings\nwhen compiled with cc -Wall.\n\n* Where possible and appropriate, example programs should allow exper-\nimentation, by varying their behavior based on inputs (ideally from\ncommand-line arguments, or alternatively, via input read by the pro-\ngram).\n\n* Example programs should be laid out according to Kernighan and\nRitchie style, with 4-space indents. (Avoid the use of TAB charac-\nters in source code!) The following command can be used to format\nyour source code to something close to the preferred style:\n\nindent -npro -kr -i4 -ts4 -sob -l72 -ss -nut -psl prog.c\n\n* For consistency, all example programs should terminate using either\nof:\n\nexit(EXITSUCCESS);\nexit(EXITFAILURE);\n\nAvoid using the following forms to terminate a program:\n\nexit(0);\nexit(1);\nreturn n;\n\n* If there is extensive explanatory text before the program source\ncode, mark off the source code with a subsection heading Program\nsource, as in:\n\n.SS Program source\n\nAlways do this if the explanatory text includes a shell session log.\n\nIf you include a shell session log demonstrating the use of a program\nor other system feature:\n\n* Place the session log above the source code listing\n\n* Indent the session log by four spaces.\n\n* Boldface the user input text, to distinguish it from output produced\nby the system.\n\nFor some examples of what example programs should look like, see\nwait(2) and pipe(2).\n", "subsections": [] }, "EXAMPLES": { "content": "For canonical examples of how man pages in the man-pages package should\nlook, see pipe(2) and fcntl(2).\n", "subsections": [] }, "SEE ALSO": { "content": "man(1), man2html(1), attributes(7), groff(7), groffman(7), man(7),\nmdoc(7)\n", "subsections": [] }, "COLOPHON": { "content": "This page is part of release 5.10 of the Linux man-pages project. A\ndescription of the project, information about reporting bugs, and the\nlatest version of this page, can be found at\nhttps://www.kernel.org/doc/man-pages/.\n\nLinux 2020-08-13 MAN-PAGES(7)", "subsections": [] } } } }