dirname3

Usage

Overview

The dirname() function is the converse of basename(3); it returns a pointer to the parent directory of the pathname pointed to by path. Any trailing ‘/’ characters are not counted as part of the directory name.

Implementation notes

The dirname() function returns a pointer to internal storage space allocated on the first call that will be overwritten by subsequent calls. dirname_r() is therefore preferred for threaded applications.

Other vendor implementations of dirname() may modify the contents of the string passed to dirname(); if portability is desired, this should be taken into account when writing code which calls this function.

Return values

If path is a null pointer, the empty string, or contains no ‘/’ characters, dirname() returns a pointer to the string ".", signifying the current directory. Otherwise, it returns a pointer to the parent directory of path.

If dirname() fails, a null pointer is returned and the global variable errno is set to indicate the error.

Errors

The following error codes may be set in errno:

[ENAMETOOLONG]

The path component to be returned was larger than MAXPATHLEN.

[ENOMEM]

The static buffer used for storing the path in dirname() could not be allocated.