REALPATH(3) BSD Programmer's Manual REALPATH(3)
realpath - returns the canonicalized absolute pathname
realpath(const char *pathname, char resolvedname[MAXPATHLEN]);
The realpath() function resolves all symbolic links, extra ``/'' charac-
ters and references to /./ and /../ in pathname, and copies the resulting
absolute pathname into the memory referenced by resolvedname. The
resolvedname argument must refer to a buffer capable of storing at least
The realpath() function will resolve both absolute and relative paths and
return the absolute pathname corresponding to pathname. All but the last
component of pathname must exist when realpath() is called.
The realpath() function returns resolved_name on success. If an error
occurs, realpath() returns NULL, and resolved_name contains the pathname
which caused the problem.
The function realpath() may fail and set the external variable errno for
any of the errors specified for the library functions chdir(2),
close(2), fchdir(2), lstat(2), open(2), readlink(2) and getcwd(3).
This implementation of realpath() differs slightly from the Solaris im-
plementation. The 4.4BSD version always returns absolute pathnames,
whereas the Solaris implementation will, under certain circumstances, re-
turn a relative resolved_path when given a relative pathname.
The realpath() function call first appeared in 4.4BSD.
4.4BSD February 16, 1994 1