# apropos - search the manual page names and descriptions - man(1) - [phpMan] > **TLDR:** Search the manual pages for names and descriptions. > - Search for a keyword using a `regex`: `apropos {{regex}}` - Search without restricting the output to the terminal width (long output): `apropos {{-l|--long}} {{regex}}` - Search for pages that match all the `regex` given: `apropos {{regex_1}} {{-a|--and}} {{regex_2}} {{-a|--and}} {{regex_3}}` *Source: tldr-pages* --- [_APROPOS_(1)](https://www.chedong.com/phpMan.php/man/APROPOS/1/markdown) Manual pager utils [_APROPOS_(1)](https://www.chedong.com/phpMan.php/man/APROPOS/1/markdown) ## NAME apropos - search the manual page names and descriptions ## SYNOPSIS **apropos **[**-dalv?V**] [**-e**|**-w**|**-r**] [**-s _**list_] [**-m _**system_[,...]] [**-M _**path_] [**-L _**locale_] [**-C _**file_] _key‐_ _word_ ... ## DESCRIPTION Each manual page has a short description available within it. **apropos **searches the descrip‐ tions for instances of _keyword_. _keyword_ is usually a regular expression, as if (**-r**) was used, or may contain wildcards (**-w**), or match the exact keyword (**-e**). Using these options, it may be necessary to quote the _key‐_ _word_ or escape (\) the special characters to stop the shell from interpreting them. The standard matching rules allow matches to be made against the page name and word bound‐ aries in the description. The database searched by **apropos **is updated by the **mandb **program. Depending on your instal‐ lation, this may be run by a periodic cron job, or may need to be run manually after new man‐ ual pages have been installed. ## OPTIONS ### -d --debug Print debugging information. ### -v --verbose Print verbose warning messages. ### -r --regex Interpret each keyword as a regular expression. This is the default behaviour. Each keyword will be matched against the page names and the descriptions independently. It can match any part of either. The match is not limited to word boundaries. ### -w --wildcard Interpret each keyword as a pattern containing shell style wildcards. Each keyword will be matched against the page names and the descriptions independently. If **--exact** is also used, a match will only be found if an expanded keyword matches an entire de‐ scription or page name. Otherwise the keyword is also allowed to match on word bound‐ aries in the description. ### -e --exact Each keyword will be exactly matched against the page names and the descriptions. ### -a --and Only display items that match all the supplied keywords. The default is to display items that match any keyword. ### -l --long Do not trim output to the terminal width. Normally, output will be truncated to the terminal width to avoid ugly results from poorly-written **NAME **sections. ### -s _ --sections=_ --section=_ Search only the given manual sections. _list_ is a colon- or comma-separated list of sections. If an entry in _list_ is a simple section, for example "3", then the dis‐ played list of descriptions will include pages in sections "3", "3perl", "3x", and so on; while if an entry in _list_ has an extension, for example "3perl", then the list will only include pages in that exact part of the manual section. ### -m _ --systems=_ If this system has access to other operating systems' manual page descriptions, they can be searched using this option. To search NewOS's manual page descriptions, use the option **-m NewOS**. The _system_ specified can be a combination of comma-delimited operating system names. To include a search of the native operating system's **whatis **descriptions, include the system name **man **in the argument string. This option will override the $**SYSTEM **envi‐ ronment variable. ### -M _ --manpath=_ Specify an alternate set of colon-delimited manual page hierarchies to search. By de‐ fault, **apropos **uses the $**MANPATH **environment variable, unless it is empty or unset, in which case it will determine an appropriate manpath based on your $**PATH **environment variable. This option overrides the contents of $**MANPATH**. ### -L _ --locale=_ **apropos **will normally determine your current locale by a call to the C function **setlo‐** [**cale**(3)](https://www.chedong.com/phpMan.php/man/cale/3/markdown) which interrogates various environment variables, possibly including $**LC_MES‐** **SAGES **and $**LANG**. To temporarily override the determined value, use this option to supply a _locale_ string directly to **apropos**. Note that it will not take effect until the search for pages actually begins. Output such as the help message will always be displayed in the initially determined locale. ### -C _ --config-file=_ Use this user configuration file rather than the default of _~/.manpath_. **-?**, **--help** Print a help message and exit. ### --usage Print a short usage message and exit. ### -V --version Display version information. ## EXIT STATUS **0 **Successful program execution. **1 **Usage, syntax or configuration file error. **2 **Operational error. **16 **Nothing was found that matched the criteria specified. ## ENVIRONMENT **SYSTEM **If $**SYSTEM **is set, it will have the same effect as if it had been specified as the ar‐ gument to the **-m **option. **MANPATH** If $**MANPATH **is set, its value is interpreted as the colon-delimited manual page hier‐ archy search path to use. See the **SEARCH PATH **section of [**manpath**(5)](https://www.chedong.com/phpMan.php/man/manpath/5/markdown) for the default behaviour and details of how this environment variable is handled. **MANWIDTH** If $**MANWIDTH **is set, its value is used as the terminal width (see the **--long **option). If it is not set, the terminal width will be calculated using the value of $**COLUMNS**, and [**ioctl**(2)](https://www.chedong.com/phpMan.php/man/ioctl/2/markdown) if available, or falling back to 80 characters if all else fails. **POSIXLY_CORRECT** If $**POSIXLY_CORRECT **is set, even to a null value, the default **apropos **search will be as an extended regex (**-r**). Nowadays, this is the default behaviour anyway. ## FILES _/usr/share/man/index.(bt|db|dir|pag)_ A traditional global _index_ database cache. _/var/cache/man/index.(bt|db|dir|pag)_ An FHS compliant global _index_ database cache. _/usr/share/man/.../whatis_ A traditional **whatis **text database. ## SEE ALSO [**man**(1)](https://www.chedong.com/phpMan.php/man/man/1/markdown), [**whatis**(1)](https://www.chedong.com/phpMan.php/man/whatis/1/markdown), [**mandb**(8)](https://www.chedong.com/phpMan.php/man/mandb/8/markdown) ## AUTHOR Wilf. (). Fabrizio Polacco (). Colin Watson (). ## BUGS 2.12.0 2023-09-23 [_APROPOS_(1)](https://www.chedong.com/phpMan.php/man/APROPOS/1/markdown)