freebsd-dev/lib/libc/gen/basename.3

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.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
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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