REALPATH(3) Library Functions Manual REALPATH(3)

realpath — resolve a pathname

#include <stdlib.h>

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

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, up to a maximum of {PATH_MAX} bytes, in the buffer pointed to by resolved_name .

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 undefined.

The realpath() function will fail if:

Read or search permission was denied for a component of file_name .
Either the file_name or resolved_name argument is a null pointer.
An error occurred while reading from the file system.
Too many symbolic links were encountered in resolving path .
The file_name argument is longer than {PATH_MAX} or a pathname component is longer than {NAME_MAX}.
A component of file_name does not name an existing file or file_name points to an empty string.
A component of the path prefix is not a directory.

The function may fail if:

Pathname resolution of a symbolic link produced an intermediate result whose length exceeds {PATH_MAX}.
Insufficient storage space is available.

None.

None.

None.

getcwd(3) , sysconf(3) , <stdlib.h> .

February 1997 posix.fail