canonicalize_file_name — return the canonicalized absolute pathname


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

char *canonicalize_file_name(const char *path);


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.


See realpath(3).


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

Interface Attribute Value
canonicalize_file_name() Thread safety MT-Safe

Conforming to

This function is a GNU extension.

See Also

readlink(2), realpath(3)


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Referenced By


2017-09-15 GNU Linux Programmer's Manual