REALPATH(3) BSD Library Functions Manual REALPATH(3)NAMErealpath — returns the canonicalized absolute pathname
SYNOPSIS
#include <stdlib.h>
char *
realpath(const char *restrict file_name, char *restrict resolved_name);
DESCRIPTION
The realpath() function resolves all symbolic links, extra “/” charac‐
ters, and references to /./ and /../ in file_name. If the resolved_name
argument is non-NULL, the resulting absolute pathname is copied there (it
must refer to a buffer capable of storing at least PATH_MAX characters).
As a permitted extension to the standard, if resolved_name is NULL, mem‐
ory is allocated for the resulting absolute pathname, and is returned by
realpath(). This memory should be freed by a call to free(3) when no
longer needed.
The realpath() function will resolve both absolute and relative paths and
return the absolute pathname corresponding to file_name. All components
of file_name must exist when realpath() is called.
RETURN VALUES
On success, the realpath() function returns the address of the resulting
absolute pathname, which is resolved_name if it was non-NULL, or the
address of newly allocated memory. If an error occurs, realpath()
returns NULL. If resolved_name was non-NULL, it will contains the path‐
name which caused the problem.
VARIANTS
Defining _DARWIN_C_SOURCE or _DARWIN_BETTER_REALPATH before including
stdio.h will cause the provided implementation of realpath() to use
F_GETPATH from fcntl(2) to discover the path.
ERRORS
The function realpath() may fail and set the external variable errno for
any of the errors specified for the library functions alloca(3),
getattrlist(2), getcwd(3), lstat(2), readlink(2), stat(2), and strdup(3).
LEGACY SYNOPSIS
#include <sys/param.h>
#include <stdlib.h>
The include file <sys/param.h> is necessary.
LEGACY DESCRIPTION
In legacy mode, the last component of file_name does not need to exist
when realpath() is called.
SEE ALSOfree(3), getcwd(3), compat(5)HISTORY
The realpath() function first appeared in 4.4BSD.
BSD April 5, 2008 BSD
