Log file snippets in php

        $log_string = 'done';
$file_name  = '/var/log/logfilename.log';
$handle = fopen ( $file_name, 'a+' );
if ($handle) {
fwrite ( $handle, date ( 'Y-m-d H:i:s' ) . '  ' . $log_string . "\n" );
fclose ( $handle );
        }