canonicalize_file_name(3)

canonicalize_file_name3

Return the canonicalized absolute pathname

Usage

#define _GNU_SOURCE         /* See feature_test_macros(7) */
#include <stdlib.h>

char *canonicalize_file_name(const char *path);

Library

Standard C library (libc, -lc)

Overview

The canonicalize_file_name() function returns a null-terminated string containing the canonicalized absolute pathname corresponding to path. In the returned string, symbolic links are resolved, as are . and .. pathname components. Consecutive slash (/) characters are replaced by a single slash.

The returned string is dynamically allocated by canonicalize_file_name() and the caller should deallocate it with free(3) when it is no longer required.

The call canonicalize_file_name(path) is equivalent to the call:

realpath(path, NULL);

Return value

On success, canonicalize_file_name() returns a null-terminated string. On error (e.g., a pathname component is unreadable or does not exist), canonicalize_file_name() returns NULL and sets errno to indicate the error.

Errors

See realpath(3).

Attributes

For an explanation of the terms used in this section, see attributes(7).

InterfaceAttributeValue
canonicalize_file_name()Thread safetyMT-Safe

Releases

11 releases since Debian 4.0 (Etch); the text changed 10 times.

  1. 4.0
  2. 5.0
  3. 6.0
  4. 7
  5. 8
  6. 9
  7. 10
  8. 11
  9. 12
  10. 13
  11. Arch

Standards

GNU.

From man-pages 6.19-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.