freebsd-nq/lib/libc/gen/basename.3
Robert Watson a502a84d5a Add basename_r(3) to complement basename(3). basename_r(3) which accepts
a caller-allocated buffer of at least MAXPATHLEN, rather than using a
global buffer.

MFC after:	1 month
Sponsored by:	Google
2009-10-06 14:05:57 +00:00

115 lines
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.\"
.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" documentation and/or other materials provided with the distribution.
.\" 3. The name of the author may not be used to endorse or promote products
.\" derived from this software without specific prior written permission.
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.\" 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
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.\" EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
.\" PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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.\" $OpenBSD: basename.3,v 1.12 2000/04/18 03:01:25 aaron Exp $
.\" $FreeBSD$
.\"
.Dd October 6, 2009
.Dt BASENAME 3
.Os
.Sh NAME
.Nm basename
.Nd extract the base portion of a pathname
.Sh SYNOPSIS
.In libgen.h
.Ft char *
.Fn basename "const char *path"
.Ft char *
.Fn basename_r "const char *path" "char *bname"
.Sh DESCRIPTION
The
.Fn basename
function
returns the last component from the pathname pointed to by
.Fa path ,
deleting any trailing
.Sq \&/
characters.
If
.Fa path
consists entirely of
.Sq \&/
characters, a pointer to the string
.Qq \&/
is returned.
If
.Fa path
is a null pointer or the empty string, a pointer to the string
.Qq \&.
is returned.
.Pp
The
.Fn basename_r
variation accepts a buffer of at least
.Dv MAXPATHLEN
bytes in which to store the resulting component.
.Sh IMPLEMENTATION NOTES
The
.Fn basename
function
returns a pointer to internal storage space allocated on the first call
that will be overwritten
by subsequent calls.
.Fn basename_r
is therefore preferred for threaded applications.
.Sh RETURN VALUES
On successful completion,
.Fn basename
and
.Fn basename_r
return pointers to the last component of
.Fa path .
.Pp
If they 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
.Dv MAXPATHLEN .
.El
.Sh SEE ALSO
.Xr basename 1 ,
.Xr dirname 1 ,
.Xr dirname 3
.Sh STANDARDS
The
.Fn basename
function conforms to
.St -xpg4.2 .
.Sh HISTORY
The
.Fn basename
function first appeared in
.Ox 2.2
and
.Fx 4.2 .
.Sh AUTHORS
.An "Todd C. Miller" Aq Todd.Miller@courtesan.com