Returns the time the file was last accessed, or FALSE in case of an error. The time is returned as a Unix timestamp.
Note: The atime of a file is supposed to change whenever the data blocks of a file are being read. This can be costly performance-wise when an application regularly accesses a very large number of files or directories. Some Unix filesystems can be mounted with atime updates disabled to increase the performance of such applications; USENET news spools are a common example. On such filesystems this function will be useless.
Note: The results of this function are cached. See clearstatcache() for more details.