whatis
display manual page descriptions
see also :
apropos - man - mandb
Synopsis
whatis
[-dlhvV] [-r|-w]
[-s list] [-m
system[,...]] [-M path]
[-L locale] [-C
file] name ...
add an example, a script, a trick and tips
examples
source
source ./port_checker_common
mymail="example@example.ru"
whatis `get_net_cat_name` | mailx -s
"Port_checker requirements" $mymail
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 list,
--sections list,
--section list
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 displayed 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
system[,...],
--systems=system[,...]
If this system has access to
other operating system’s 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 environment
variable.
-M path, --manpath=path
Specify an alternate set of
colon-delimited manual page hierarchies to search. By
default, 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, --locale=locale
whatis will normally
determine your current locale by a call to the C function
setlocale(3) which interrogates various environment
variables, possibly including $LC_MESSAGES 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 file, --config-file=file
Use this user configuration
file rather than the default of ~/.manpath.
-h,
--help
Print a help message and
exit.
-V,
--version
Display version
information.
environment
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.
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.
system
If $SYSTEM is set, it will have the same effect as if it
had been specified as the argument to the -m option.
MANPATH
If $MANPATH is set, its value is interpreted as the
colon-delimited manual page hierarchy search path to use.
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 an ioctl(2) if
available, the value of $COLUMNS, or falling back to 80
characters if all else fails.
see also
apropos ,
man , mandb
author
Wilf.
(G.Wilford[:at:]ee.surrey.ac[:dot:]uk).
Fabrizio Polacco (fpolacco[:at:]debian[:dot:]org).
Colin Watson (cjwatson[:at:]debian[:dot:]org).