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realpath - resolve pathname

#include <stdlib.h>

char *realpath(const char *restrict file_name,
 char *restrict resolved_name);

char *canonicalize_file_name(const char *path);

The realpath() function derives, from the pathname pointed to by file_name, an absolute pathname that names the same file, whose resolution does not involve ".", "..", or symbolic links. The generated pathname is stored as a null-terminated string, up to a maximum of {PATH_MAX} bytes (defined in limits.h(3HEAD)), in the buffer pointed to by resolved_name.

The canonicalize_file_name() function is equivalent to calling realpath(path, NULL). This function is only provided for compatibility.

On successful completion, realpath() returns a pointer to the resolved name. Otherwise, realpath() returns a null pointer and sets errno to indicate the error, and the contents of the buffer pointed to by resolved_name are left in an indeterminate state.

The realpath() function will fail if: EACCES

EINVAL EIO ELOOP ELOOP ENAMETOOLONG ENOENT ENOTDIR

The realpath() function may fail if: ENAMETOOLONG

ENOMEM

The realpath() function operates on null-terminated strings.

Execute permission is required for all the directories in the given and the resolved path.

The realpath() function might fail to return to the current directory if an error occurs.

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE

Interface Stability Standard

MT-Level MT-Safe

getcwd (3C), sysconf (3C), limits.h (3HEAD), attributes (7), standards (7)