.\"
.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by Todd C. Miller.
.\" 4. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
.\" AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
.\" THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
.\" EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
.\" PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
.\" OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
.\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
.\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $OpenBSD: basename.3,v 1.1 1997/08/17 21:31:20 millert Exp $
.\"
.Dd August 17, 1997
.Dt BASENAME 3
.Os
.Sh NAME
.Nm basename ,
.Nm dirname
.Nd extract the base or directory portition of a pathname
.Sh SYNOPSIS
.Fd #include <libgen.h>
.Ft char *
.Fn basename "char *path"
.Ft char *
.Fn dirname "char *path"
.Sh DESCRIPTION
The
.Fn basename
function
returns the last componenent from the pathname pointed to by
.Ar path ,
deleting any trailing '/' characters.  If
.Ar path
consists entirely of '/' characters, a pointer to the string "/"
is returned.  If
.Ar path
is a NULL pointer or the empty string, a pointer to the string "."
is returned.
.Pp
The
.Fn dirname
function
is the converse of
.Fn basename ;
it returns a pointer to the parent directory of the pathname pointed to by
.Ar path .
Any trailing '/' characters are not counted as part of the directory
name.  If
.Ar path
is a NULL pointer, the empty string, or contains no '/' characters,
.Fn dirname
returns a pointer to the string ".", signifying the current directory.
.Sh RETURN VALUES
On successful completion,
.Fn basename
returns a pointer to the last component of
.Ar path.
.Pp
On successful completion,
.Fn dirname
returns a pointer to the parent directory of
.Ar path.
.Pp
If
.Fn basename
or
.Fn dirname
fail, a NULL pointer is returned and the global variable
.Va errno
is set to indicate the error.
.Sh ERRORS
The following error codes may be set in
.Va errno :
.Bl -tag -width Er
.It Bq Er ENAMETOOLONG
the path component to be returned was larger than
.Va MANPATHLEN .
.Sh WARNINGS
Both
.Fn basename
and
.Fn dirname
return pointers to internal static storage space that will be overwritten
by subsequent calls (each function has its own separate storage).
.Sh SEE ALSO
.Xr basename 1 ,
.Xr dirname 1
.Sh STANDARDS
The
.Fn basename                                                           
and
.Fn dirname
functions conform to
.St -xpg4.2 .
.Sh HISTORY
The
.Fn basename
and
.Fn dirname
functions first appeared in
.Bx Open
2.2.
.Sh AUTHOR
.nf
Todd C. Miller <Todd.Miller@courtesan.com>
.fi