Checks whether file has the prefix specified by prefix.
In other words, if the names of initial elements of file's
pathname match prefix. Only full pathname elements are matched,
so a path like /foo is not considered a prefix of /foobar, only
of /foo/bar.
This call does no I/O, as it works purely on names. As such it can
sometimes return FALSE even if file is inside a prefix (from a
filesystem point of view), because the prefix of file is an alias
of prefix.
Virtual: prefix_matches
Checks whether file has the prefix specified by prefix. In other words, if the names of initial elements of file's pathname match prefix. Only full pathname elements are matched, so a path like /foo is not considered a prefix of /foobar, only of /foo/bar. This call does no I/O, as it works purely on names. As such it can sometimes return FALSE even if file is inside a prefix (from a filesystem point of view), because the prefix of file is an alias of prefix. Virtual: prefix_matches