Returns the size of the file in bytes, or FALSE (and generates an error of level E_WARNING) 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.
See also file_exists()