xref: /dragonfly/lib/libc/gen/dirname.3 (revision b7367ef6)
1.\"
2.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
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27.\" $OpenBSD: dirname.3,v 1.9 2000/04/18 03:01:25 aaron Exp $
28.\" $FreeBSD: src/lib/libc/gen/dirname.3,v 1.1.2.6 2003/03/15 15:11:05 trhodes Exp $
29.\" $DragonFly: src/lib/libc/gen/dirname.3,v 1.3 2007/08/18 20:48:47 swildner Exp $
30.\"
31.Dd August 17, 1997
32.Dt DIRNAME 3
33.Os
34.Sh NAME
35.Nm dirname
36.Nd extract the directory part of a pathname
37.Sh LIBRARY
38.Lb libc
39.Sh SYNOPSIS
40.In libgen.h
41.Ft char *
42.Fn dirname "const char *path"
43.Sh DESCRIPTION
44The
45.Fn dirname
46function
47is the converse of
48.Xr basename 3 ;
49it returns a pointer to the parent directory of the pathname pointed to by
50.Fa path .
51Any trailing
52.Sq \&/
53characters are not counted as part of the directory
54name.
55If
56.Fa path
57is a null pointer, the empty string, or contains no
58.Sq \&/
59characters,
60.Fn dirname
61returns a pointer to the string
62.Qq \&. ,
63signifying the current directory.
64.Sh RETURN VALUES
65On successful completion,
66.Fn dirname
67returns a pointer to the parent directory of
68.Fa path .
69.Pp
70If
71.Fn dirname
72fails, a null pointer is returned and the global variable
73.Va errno
74is set to indicate the error.
75.Sh ERRORS
76The following error codes may be set in
77.Va errno :
78.Bl -tag -width Er
79.It Bq Er ENAMETOOLONG
80The path component to be returned was larger than
81.Dv MAXPATHLEN .
82.El
83.Sh WARNINGS
84The
85.Fn dirname
86function
87returns a pointer to internal static storage space that will be overwritten
88by subsequent calls (each function has its own separate storage).
89.Pp
90Other vendor implementations of
91.Fn dirname
92may modify the contents of the string passed to
93.Fn dirname ;
94this should be taken into account when writing code which calls this function
95if portability is desired.
96.Sh SEE ALSO
97.Xr basename 1 ,
98.Xr dirname 1 ,
99.Xr basename 3
100.Sh STANDARDS
101The
102.Fn dirname
103function conforms to
104.St -xpg4.2 .
105.Sh HISTORY
106The
107.Fn dirname
108function first appeared in
109.Ox 2.2
110and
111.Fx 4.2 .
112.Sh AUTHORS
113Todd C. Miller <Todd.Miller@courtesan.com>
114