[apple/libc.git] / gen / FreeBSD / dirname.3

.\" $OpenBSD: dirname.3,v 1.17 2007/05/31 19:19:28 jmc Exp $
.\"
.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.\" $FreeBSD: src/lib/libc/gen/dirname.3,v 1.10 2008/11/03 05:19:45 delphij Exp $
.\"
.Dd October 12, 2006
.Dt DIRNAME 3
.Os
.Sh NAME
.Nm dirname
.Nd extract the directory part of a pathname
.Sh SYNOPSIS
.In libgen.h
.Ft char *
.Fn dirname "const char *path"
.Sh DESCRIPTION
The
.Fn dirname
function is the converse of
.Xr basename 3 ;
it returns a pointer to the parent directory of the pathname pointed to by
.Fa path .
Any trailing
.Sq \&/
characters are not counted as part of the directory
name.
If
.Fa path
is a null pointer, the empty string, or contains no
.Sq \&/
characters,
.Fn dirname
returns a pointer to the string
.Qq \&. ,
signifying the current directory.
.Sh IMPLEMENTATION NOTES
The
.Fn dirname
function
returns a pointer to internal storage space allocated on the first call
that will be overwritten
by subsequent calls.
.Pp
Other vendor implementations of
.Fn dirname
may modify the contents of the string passed to
.Fn dirname ;
this should be taken into account when writing code which calls this function
if portability is desired.
.Sh RETURN VALUES
On successful completion,
.Fn dirname
returns a pointer to the parent directory of
.Fa path .
.Pp
If
.Fn dirname
fails, 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 basename 3
.Sh STANDARDS
The
.Fn dirname
function conforms to
.St -xpg4.2 .
.Sh HISTORY
The
.Fn dirname
function first appeared in
.Ox 2.2
and
.Fx 4.2 .
.Sh AUTHORS
.An "Todd C. Miller"
Commit	Line	Data
1f2f436a	1	.\" $OpenBSD: dirname.3,v 1.17 2007/05/31 19:19:28 jmc Exp $
5b2abdfb A	2	.\"
5b2abdfb A	3	.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
5b2abdfb	4	.\"
1f2f436a A	5	.\" Permission to use, copy, modify, and distribute this software for any
	6	.\" purpose with or without fee is hereby granted, provided that the above
	7	.\" copyright notice and this permission notice appear in all copies.
5b2abdfb	8	.\"
1f2f436a A	9	.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	10	.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	11	.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	12	.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	13	.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	14	.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	15	.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
5b2abdfb	16	.\"
1f2f436a	17	.\" $FreeBSD: src/lib/libc/gen/dirname.3,v 1.10 2008/11/03 05:19:45 delphij Exp $
5b2abdfb	18	.\"
1f2f436a	19	.Dd October 12, 2006
5b2abdfb A	20	.Dt DIRNAME 3
	21	.Os
	22	.Sh NAME
	23	.Nm dirname
9385eb3d	24	.Nd extract the directory part of a pathname
5b2abdfb A	25	.Sh SYNOPSIS
	26	.In libgen.h
	27	.Ft char *
	28	.Fn dirname "const char *path"
	29	.Sh DESCRIPTION
	30	The
	31	.Fn dirname
1f2f436a	32	function is the converse of
5b2abdfb A	33	.Xr basename 3 ;
5b2abdfb A	34	it returns a pointer to the parent directory of the pathname pointed to by
9385eb3d	35	.Fa path .
5b2abdfb A	36	Any trailing
	37	.Sq \&/
	38	characters are not counted as part of the directory
	39	name.
	40	If
9385eb3d	41	.Fa path
5b2abdfb A	42	is a null pointer, the empty string, or contains no
	43	.Sq \&/
	44	characters,
	45	.Fn dirname
	46	returns a pointer to the string
	47	.Qq \&. ,
	48	signifying the current directory.
1f2f436a A	49	.Sh IMPLEMENTATION NOTES
	50	The
	51	.Fn dirname
	52	function
	53	returns a pointer to internal storage space allocated on the first call
	54	that will be overwritten
	55	by subsequent calls.
	56	.Pp
	57	Other vendor implementations of
	58	.Fn dirname
	59	may modify the contents of the string passed to
	60	.Fn dirname ;
	61	this should be taken into account when writing code which calls this function
	62	if portability is desired.
5b2abdfb A	63	.Sh RETURN VALUES
	64	On successful completion,
	65	.Fn dirname
	66	returns a pointer to the parent directory of
9385eb3d	67	.Fa path .
5b2abdfb A	68	.Pp
	69	If
	70	.Fn dirname
	71	fails, a null pointer is returned and the global variable
	72	.Va errno
	73	is set to indicate the error.
	74	.Sh ERRORS
	75	The following error codes may be set in
	76	.Va errno :
	77	.Bl -tag -width Er
	78	.It Bq Er ENAMETOOLONG
	79	The path component to be returned was larger than
	80	.Dv MAXPATHLEN .
	81	.El
5b2abdfb A	82	.Sh SEE ALSO
	83	.Xr basename 1 ,
	84	.Xr dirname 1 ,
	85	.Xr basename 3
	86	.Sh STANDARDS
	87	The
	88	.Fn dirname
	89	function conforms to
	90	.St -xpg4.2 .
	91	.Sh HISTORY
	92	The
	93	.Fn dirname
	94	function first appeared in
	95	.Ox 2.2
	96	and
	97	.Fx 4.2 .
	98	.Sh AUTHORS
1f2f436a	99	.An "Todd C. Miller"