note 63832 deleted from function.flock by danbrown

Note Submitter: heshan at sjtu dot edu dot cn ---- dranger at export dash japan dot com 's suggestion is correct and useful. My purpose is just preventing any other process from disturbing the current process which is rewriting a "cache" file, and flock() itself can help me to achieve this. $fp = fopen( "test.txt", "ab" ); if( $fp && flock( $fp, LOCK_EX ) ) { ftruncate( $fp, 0 ); fwrite( $fp, $part_one ); sleep( 10 ); // for test purpose, assume the whole writing process takes 10 seconds fwrite( $fp, $part_two ); fclose( $fp ); } it works well, I open 3 browser windows to request this page, and the third one actually takes more than 20( about 26 ) seconds to finish. and the content of cache.txt is correct and up-to-time. tested under: 1, windows, apache2, php4.4.1 2, freebsd, apache, php4.2.3