xref: /illumos-gate/usr/src/man/man3c/dirname.3c (revision 2bbdd445a21f9d61f4a0ca0faf05d5ceb2bd91f3)
te
Copyright 1989 AT&T Copyright (c) 2002, Sun Microsystems, Inc. All Rights Reserved Portions Copyright (c) 1992, X/Open Company Limited All Rights Reserved
Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.
The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.
This notice shall appear on any product containing this material.
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
DIRNAME 3C "Mar 18, 2002"
NAME
dirname - report the parent directory name of a file path name
SYNOPSIS

#include <libgen.h>

char *dirname(char *path);
DESCRIPTION

The dirname() function takes a pointer to a character string that contains a pathname, and returns a pointer to a string that is a pathname of the parent directory of that file. Trailing '/' characters in the path are not counted as part of the path.

If path does not contain a '/', then dirname() returns a pointer to the string "." . If path is a null pointer or points to an empty string, dirname() returns a pointer to the string "." .

RETURN VALUES

The dirname() function returns a pointer to a string that is the parent directory of path. If path is a null pointer or points to an empty string, a pointer to a string "." is returned.

ERRORS

No errors are defined.

EXAMPLES

Example 1 Changing the Current Directory to the Parent Directory.

The following code fragment reads a pathname, changes the current working directory to the parent directory of the named file (see chdir(2)), and opens the file.

char path[[MAXPATHLEN], *pathcopy;
int fd;
fgets(path, MAXPATHLEN, stdin);
pathcopy = strdup(path);
chdir(dirname(pathcopy));
fd = open(basename(path), O_RDONLY);

Example 2 Sample Input and Output Strings for dirname().

In the following table, the input string is the value pointed to by path, and the output string is the return value of the dirname() function.

Input String Output String
"/usr/lib"" "/usr"
"/usr/" "/"
"usr" "/"
"/" "/"
"." "."
".." "."
USAGE

The dirname() function modifies the string pointed to by path.

The dirname() and basename(3C) functions together yield a complete pathname. The expression dirname(path) obtains the pathname of the directory where basename(path) is found.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Standard
MT-Level MT-Safe
SEE ALSO

basename(1), chdir(2), basename(3C), attributes(5), standards(5)