NAME

realpath — returns the canonicalized absolute pathname

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <stdlib.h>

char *
realpath(const char * restrict pathname, char * restrict resolved_path);

DESCRIPTION

The realpath() function resolves all symbolic links, extra “/” characters and references to /./ and /../ in pathname, and copies the resulting absolute pathname into the memory pointed to by resolved_path. The resolved_path argument must point to a buffer capable of storing at least PATH_MAX characters, or be NULL.

The realpath() function will resolve both absolute and relative paths and return the absolute pathname corresponding to pathname. All components of pathname must exist when realpath() is called, and all but the last component must name either directories or symlinks pointing to the directories.

RETURN VALUES

The realpath() function returns resolved_path on success. If the function was supplied NULL as resolved_path, and operation did not cause errors, the returned value is a null-terminated string in a buffer allocated by a call to malloc(3). If an error occurs, realpath() returns NULL, and if resolved_path is not NULL, the array that it points to contains the pathname which caused the problem.

ERRORS

The function realpath() may fail and set the external variable errno for any of the errors specified for the library functions lstat(2), readlink(2) and getcwd(3).

HISTORY

The realpath() function first appeared in 4.4BSD.

CAVEATS

This implementation of realpath() differs slightly from the Solaris implementation. The 4.4BSD version always returns absolute pathnames, whereas the Solaris implementation will, under certain circumstances, return a relative resolved_path when given a relative pathname.