Returns the time the file was last changed, or FALSE in case of an error. The
time is returned as a Unix timestamp.
The results of this function are cached. See
clearstatcache() for more details.
Note: In most Unix filesystems, a file is considered
changed when its inode data is changed; that is, when the
permissions, owner, group, or other metadata from the inode
is updated. See also filemtime() (which is what you want
to use when you want to create "Last Modified" footers on web
pages) and fileatime().
Note also that in some Unix texts the ctime of a file is
referred to as being the creation time of the file. This is
wrong. There is no creation time for Unix files in most Unix
filesystems.
This function will not work on remote files; the file to be
examined must be accessible via the server's filesystem.