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

.\"
.\" 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. 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: dirname.3,v 1.9 2000/04/18 03:01:25 aaron Exp $
.\" $FreeBSD: src/lib/libc/gen/dirname.3,v 1.8 2004/07/02 23:52:10 ru Exp $
.\"
.Dd August 17, 1997
.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 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 WARNINGS
The
.Fn dirname
function
returns a pointer to internal static storage space that will be overwritten
by subsequent calls (each function has its own separate storage).
.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 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" Aq Todd.Miller@courtesan.com
Commit	Line	Data
224c7076 A	1	.\"
	2	.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
	3	.\" All rights reserved.
	4	.\"
	5	.\" Redistribution and use in source and binary forms, with or without
	6	.\" modification, are permitted provided that the following conditions
	7	.\" are met:
	8	.\" 1. Redistributions of source code must retain the above copyright
	9	.\" notice, this list of conditions and the following disclaimer.
	10	.\" 2. Redistributions in binary form must reproduce the above copyright
	11	.\" notice, this list of conditions and the following disclaimer in the
	12	.\" documentation and/or other materials provided with the distribution.
	13	.\" 3. The name of the author may not be used to endorse or promote products
	14	.\" derived from this software without specific prior written permission.
	15	.\"
	16	.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
	17	.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
	18	.\" AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
	19	.\" THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	20	.\" EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	21	.\" PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
	22	.\" OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
	23	.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
	24	.\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
	25	.\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	26	.\"
	27	.\" $OpenBSD: dirname.3,v 1.9 2000/04/18 03:01:25 aaron Exp $
	28	.\" $FreeBSD: src/lib/libc/gen/dirname.3,v 1.8 2004/07/02 23:52:10 ru Exp $
	29	.\"
	30	.Dd August 17, 1997
	31	.Dt DIRNAME 3
	32	.Os
	33	.Sh NAME
	34	.Nm dirname
	35	.Nd extract the directory part of a pathname
	36	.Sh SYNOPSIS
	37	.In libgen.h
	38	.Ft char *
	39	.Fo dirname
	40	.Fa "char *path"
	41	.Fc
	42	.Sh DESCRIPTION
	43	The
	44	.Fn dirname
	45	function
	46	is the converse of
	47	.Xr basename 3 ;
	48	it returns a pointer to the parent directory of the pathname pointed to by
	49	.Fa path .
	50	Any trailing
	51	.Sq \&/
	52	characters are not counted as part of the directory
	53	name.
	54	If
	55	.Fa path
	56	is a null pointer, the empty string, or contains no
	57	.Sq \&/
	58	characters,
	59	.Fn dirname
	60	returns a pointer to the string
	61	.Qq \&. ,
	62	signifying the current directory.
	63	.Sh RETURN VALUES
	64	On successful completion,
65	.Fn dirname
66	returns a pointer to the parent directory of
67	.Fa path .
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
82	.Sh WARNINGS
83	The
84	.Fn dirname
85	function
86	returns a pointer to internal static storage space that will be overwritten
87	by subsequent calls (each function has its own separate storage).
88	.Pp
89	Other vendor implementations of
90	.Fn dirname
91	may modify the contents of the string passed to
92	.Fn dirname ;
93	if portability is desired,
94	this should be taken into account when writing code which calls this function.
95	.Sh LEGACY SYNOPSIS
96	.Fd #include <libgen.h>
97	.Pp
98	.Ft char *
99	.br
100	.Fo dirname
101	.Fa "const char *path"
102	.Fc ;
103	.Pp
104	In legacy mode,
105	.Fa path
106	will not be changed.
107	.Sh SEE ALSO
108	.Xr basename 1 ,
109	.Xr dirname 1 ,
110	.Xr basename 3 ,
111	.Xr compat 5
112	.Sh STANDARDS
113	The
114	.Fn dirname
115	function conforms to
116	.St -xpg4.2 .
117	.Sh HISTORY
118	The
119	.Fn dirname
120	function first appeared in
121	.Ox 2.2
122	and
123	.Fx 4.2 .
124	.Sh AUTHORS
125	.An "Todd C. Miller" Aq Todd.Miller@courtesan.com