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.\"     @(#)whatis.1	8.1 (Berkeley) 6/6/93
.\"
.Dd $Mdocdate: December 26 2011 $
.Dt WHATIS 1
.Os
.Sh NAME
.Nm whatis
.Nd describe what a command is
.Sh SYNOPSIS
.Nm whatis
.Op Fl C Ar file
.Op Fl M Ar path
.Op Fl m Ar path
.Op Fl S Ar arch
.Op Fl s Ar section
.Ar command ...
.Sh DESCRIPTION
.Nm
looks up a given command and gives the header line from the manual page.
You can then use the
.Xr man 1
command to get more information.
.Nm
will match on a case insensitive basis and for multiple word entries
will match on each individual word.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl C Ar file
Specify an alternate configuration file in
.Xr man.conf 5
format.
The default is
.Pa /etc/man.conf .
.It Fl M Ar path
Override the list of standard directories
.Nm
searches for its database named
.Dq Pa whatis.db .
The supplied
.Ar path
must be a colon
.Pq Ql \&:
separated list of directories.
This search path may also be set using the environment variable
.Ev MANPATH .
.It Fl m Ar path
Augment the list of standard directories
.Nm
searches for its database named
.Dq Pa whatis.db .
The supplied
.Ar path
must be a colon-separated list of directories.
These directories will be searched before the standard directories
or the directories supplied with the
.Fl M
option or the
.Ev MANPATH
environment variable are searched.
.It Fl S Ar arch
Restrict the search to pages for the specified
.Xr machine 1
architecture.
.Ar arch
is case insensitive.
By default, pages for all architectures are shown.
.It Fl s Ar section
Restrict the search to the specified section of the manual.
By default, pages from all sections are shown.
See
.Xr man 1
for a listing of sections.
.El
.Sh ENVIRONMENT
.Bl -tag -width MANPATH
.It Ev MANPATH
The standard search path used by
.Xr man 1
may be changed by specifying a path in the
.Ev MANPATH
environment variable.
If
.Ev MANPATH
begins with a colon, it is appended to the default list;
if it ends with a colon, it is prepended to the default list;
or if it contains two adjacent colons,
the standard search path is inserted between the colons.
If none of these conditions are met, it overrides the
standard search path.
.El
.Sh FILES
.Bl -tag -width "/etc/man.conf" -compact
.It Pa whatis.db
name of the
.Xr mandocdb 8
keyword database
.It Pa whatis.index
name of the
.Xr mandocdb 8
filename database
.It Pa /etc/man.conf
default
.Xr man 1
configuration file
.El
.Sh SEE ALSO
.Xr apropos 1 ,
.Xr man 1 ,
.Xr whereis 1 ,
.Xr which 1 ,
.Xr man.conf 5 ,
.Xr makewhatis 8
.Sh HISTORY
The
.Nm
command first appeared in
.Bx 2 .
.Pp
The
.Fl M
option first appeared in
.Bx 4.3 Tahoe ;
.Fl m
in
.Bx 4.3 Reno ;
and
.Fl C
in
.Nx 1.0 .
.Sh AUTHORS
.An Bill Joy