basename(3)

basename3

Extract the base portion of a pathname

Usage

#include <libgen.h>

char *

basename(char *path);

char *

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

Overview

The basename() function returns the last component from the pathname pointed to by path, deleting any trailing ‘/’ characters.

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

Implementation notes

This implementation of basename() 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. 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.

Return values

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. Otherwise, they return a pointer 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.

Errors

The following error codes may be set in errno:

[ENAMETOOLONG]

The path component to be returned was larger than MAXPATHLEN.

Releases

155 releases since Mac OS X 10.2; the text changed 5 times.

  1. 10.2–10.2.8
  2. 10.3–10.3.9
  3. 10.4–10.4.11
  4. 10.5–10.11.6
  5. 10.12–15.6
  6. 26.0–26.5

Standards

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

History

The basename() function first appeared in OpenBSD 2.2 and FreeBSD 4.2.

The basename_r() function first appeared in OS X 10.12.

Authors

Nuxi, the Netherlands

From Libc 1752.120.2 in macOS 26.5. Parsed by carta from the page's mdoc source.