[apple/libc.git] / gen / 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 *
.Fo dirname
.Fa "char *path"
.Fc
.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 ;
if portability is desired,
this should be taken into account when writing code which calls this function.
.Sh LEGACY SYNOPSIS
.Fd #include <libgen.h>
.Pp
.Ft char *
.br
.Fo dirname
.Fa "const char *path"
.Fc ;
.Pp
In legacy mode,
.Fa path
will not be changed.
.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 ,
.Xr compat 5
.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 $
224c7076 A	2	.\"
224c7076 A	3	.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
224c7076	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.
224c7076	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.
224c7076	16	.\"
1f2f436a	17	.\" $FreeBSD: src/lib/libc/gen/dirname.3,v 1.10 2008/11/03 05:19:45 delphij Exp $
224c7076	18	.\"
1f2f436a	19	.Dd October 12, 2006
224c7076 A	20	.Dt DIRNAME 3
	21	.Os
	22	.Sh NAME
	23	.Nm dirname
	24	.Nd extract the directory part of a pathname
	25	.Sh SYNOPSIS
	26	.In libgen.h
	27	.Ft char *
	28	.Fo dirname
	29	.Fa "char *path"
	30	.Fc
	31	.Sh DESCRIPTION
	32	The
	33	.Fn dirname
1f2f436a	34	function is the converse of
224c7076 A	35	.Xr basename 3 ;
	36	it returns a pointer to the parent directory of the pathname pointed to by
	37	.Fa path .
	38	Any trailing
	39	.Sq \&/
	40	characters are not counted as part of the directory
	41	name.
	42	If
	43	.Fa path
	44	is a null pointer, the empty string, or contains no
	45	.Sq \&/
	46	characters,
	47	.Fn dirname
	48	returns a pointer to the string
	49	.Qq \&. ,
	50	signifying the current directory.
1f2f436a	51	.Sh IMPLEMENTATION NOTES
224c7076 A	52	The
	53	.Fn dirname
	54	function
1f2f436a A	55	returns a pointer to internal storage space allocated on the first call
	56	that will be overwritten
	57	by subsequent calls.
224c7076 A	58	.Pp
	59	Other vendor implementations of
	60	.Fn dirname
	61	may modify the contents of the string passed to
	62	.Fn dirname ;
	63	if portability is desired,
	64	this should be taken into account when writing code which calls this function.
	65	.Sh LEGACY SYNOPSIS
	66	.Fd #include <libgen.h>
	67	.Pp
	68	.Ft char *
	69	.br
	70	.Fo dirname
	71	.Fa "const char *path"
	72	.Fc ;
	73	.Pp
	74	In legacy mode,
	75	.Fa path
	76	will not be changed.
1f2f436a A	77	.Sh RETURN VALUES
	78	On successful completion,
	79	.Fn dirname
	80	returns a pointer to the parent directory of
	81	.Fa path .
	82	.Pp
	83	If
	84	.Fn dirname
	85	fails, a null pointer is returned and the global variable
	86	.Va errno
	87	is set to indicate the error.
	88	.Sh ERRORS
	89	The following error codes may be set in
	90	.Va errno :
	91	.Bl -tag -width Er
	92	.It Bq Er ENAMETOOLONG
	93	The path component to be returned was larger than
	94	.Dv MAXPATHLEN .
	95	.El
224c7076 A	96	.Sh SEE ALSO
	97	.Xr basename 1 ,
	98	.Xr dirname 1 ,
	99	.Xr basename 3 ,
	100	.Xr compat 5
	101	.Sh STANDARDS
	102	The
	103	.Fn dirname
	104	function conforms to
	105	.St -xpg4.2 .
	106	.Sh HISTORY
	107	The
	108	.Fn dirname
	109	function first appeared in
	110	.Ox 2.2
	111	and
	112	.Fx 4.2 .
	113	.Sh AUTHORS
1f2f436a	114	.An "Todd C. Miller"