BASENAME(3) Library Functions Manual BASENAME(3)

basenameextract the base portion of a pathname

#include <libgen.h>

char *
basename(char *path);

char *
basename_r(const char *path, char *bname);

The () function returns the last component from the pathname pointed to by path, deleting any trailing ‘/’ characters. If path consists entirely of ‘/’ characters, a pointer to the string "/" is returned. If path is a null pointer or the empty string, a pointer to the string "." is returned.

The () variation accepts a buffer of at least MAXPATHLEN bytes in which to store the resulting component.

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

On successful completion, basename() and basename_r() return pointers to the last component of path.

If they fail, a null pointer is returned and the global variable errno is set to indicate the error.

The following error codes may be set in errno:

[]
The path component to be returned was larger than MAXPATHLEN.

basename(1), dirname(1), dirname(3)

The basename() function conforms to X/Open Portability Guide Issue 4, Version 2 (“XPG4.2”).

The basename() function first appeared in OpenBSD 2.2 and FreeBSD 4.2. The basename_r() function first appeared in OS X 10.12.

Todd C. Miller

basename() returns a pointer to internal static storage space that will be overwritten by subsequent calls.

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

March 31, 2010 macOS 15.2