# whatis(1) - man - phpMan

[WHATIS(1)](https://www.chedong.com/phpMan.php/man/WHATIS/1/markdown)                                Manual pager utils                                [WHATIS(1)](https://www.chedong.com/phpMan.php/man/WHATIS/1/markdown)



## NAME
       whatis - display one-line manual page descriptions

## SYNOPSIS
       **whatis** [**-dlv?V**] [**-r**|**-w**] [**-s** _list_] [**-m** _system_[,...]] [**-M** _path_] [**-L** _locale_] [**-C** _file_] _name_ ...

## DESCRIPTION
       Each  manual  page  has  a short description available within it.  **whatis** searches the manual
       page names and displays the manual page descriptions of any _name_ matched.

       _name_ may contain wildcards (**-w**) or be a regular expression (**-r**).  Using these options, it may
       be  necessary  to  quote the _name_ or escape (\) the special characters to stop the shell from
       interpreting them.

       **index** databases are used during the search, and are updated by the **mandb** program.   Depending
       on  your installation, this may be run by a periodic cron job, or may need to be run manually
       after new manual pages have been installed.  To produce an old  style  text  **whatis**  database
       from the relative **index** database, issue the command:

       **whatis** **-M** _manpath_ **-w** **'*'** **|** **sort** **>** _manpath/whatis_

       where _manpath_ is a manual page hierarchy such as _/usr/man_.

## OPTIONS
### -d --debug
              Print debugging information.

### -v --verbose
              Print verbose warning messages.

### -r --regex
              Interpret  each  _name_  as  a regular expression.  If a _name_ matches any part of a page
              name, a match will be made.  This option causes **whatis** to be somewhat  slower  due  to
              the nature of database searches.

### -w --wildcard
              Interpret  each _name_ as a pattern containing shell style wildcards.  For a match to be
              made, an expanded _name_ must match the entire page name.  This option causes **whatis**  to
              be somewhat slower due to the nature of database searches.

### -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 names, they  can  be
              accessed  using  this  option.  To search NewOS's manual page names, 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 manual page names, 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, **whatis** 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=
              **whatis** 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 **whatis**.  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.

## 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
       [**apropos**(1)](https://www.chedong.com/phpMan.php/man/apropos/1/markdown), [**man**(1)](https://www.chedong.com/phpMan.php/man/man/1/markdown), [**mandb**(8)](https://www.chedong.com/phpMan.php/man/mandb/8/markdown)

## AUTHOR
       Wilf. (<G.Wilford@ee.surrey.ac.uk>).
       Fabrizio Polacco (<fpolacco@debian.org>).
       Colin Watson (<cjwatson@debian.org>).

## BUGS
       <https://gitlab.com/cjwatson/man-db/-/issues>
       <https://savannah.nongnu.org/bugs/?group=man-db>



2.10.2                                       2022-03-17                                    [WHATIS(1)](https://www.chedong.com/phpMan.php/man/WHATIS/1/markdown)
