Returns the size of the file in bytes, or FALSE in case of an error.
Note: Because PHP's integer type is signed and many platforms use 32bit integers, filesize() may return unexpected results for files which are larger than 2GB. For files between 2GB and 4GB in size this can usually be overcome by using sprintf("%u", filesize($file)).
Note: The results of this function are cached. See clearstatcache() for more details.
Note: This function will not work on remote files as the file to be examined must be accessible via the servers filesystem.
See also file_exists()