1.\" $OpenBSD: dirname.3,v 1.17 2007/05/31 19:19:28 jmc Exp $ 2.\" 3.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com> 4.\" 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. 8.\" 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. 16.\" 17.\" $FreeBSD$ 18.\" 19.Dd October 12, 2006 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.Fn dirname "const char *path" 29.Sh DESCRIPTION 30The 31.Fn dirname 32function is the converse of 33.Xr basename 3 ; 34it returns a pointer to the parent directory of the pathname pointed to by 35.Fa path . 36Any trailing 37.Sq \&/ 38characters are not counted as part of the directory 39name. 40If 41.Fa path 42is a null pointer, the empty string, or contains no 43.Sq \&/ 44characters, 45.Fn dirname 46returns a pointer to the string 47.Qq \&. , 48signifying the current directory. 49.Sh IMPLEMENTATION NOTES 50The 51.Fn dirname 52function 53returns a pointer to internal storage space allocated on the first call 54that will be overwritten 55by subsequent calls. 56.Pp 57Other vendor implementations of 58.Fn dirname 59may modify the contents of the string passed to 60.Fn dirname ; 61this should be taken into account when writing code which calls this function 62if portability is desired. 63.Sh RETURN VALUES 64On successful completion, 65.Fn dirname 66returns a pointer to the parent directory of 67.Fa path . 68.Pp 69If 70.Fn dirname 71fails, a null pointer is returned and the global variable 72.Va errno 73is set to indicate the error. 74.Sh ERRORS 75The following error codes may be set in 76.Va errno : 77.Bl -tag -width Er 78.It Bq Er ENAMETOOLONG 79The path component to be returned was larger than 80.Dv MAXPATHLEN . 81.El 82.Sh SEE ALSO 83.Xr basename 1 , 84.Xr dirname 1 , 85.Xr basename 3 86.Sh STANDARDS 87The 88.Fn dirname 89function conforms to 90.St -xpg4.2 . 91.Sh HISTORY 92The 93.Fn dirname 94function first appeared in 95.Ox 2.2 96and 97.Fx 4.2 . 98.Sh AUTHORS 99.An "Todd C. Miller" 100