PHP/File Directory/touch

Changing file modification times

 
<?php
touch("shemp.php");          // set modification time to now
touch("joe.php",$timestamp); // set modification time to $timestamp
?>

Error-prone file locking

 
<?
$locked = 0;
while (! $locked) {
    if (! file_exists("guestbook.txt.lock")) {
        touch("guestbook.txt.lock");
        $locked = 1;
    } else {
        sleep(1);
    }
}
?>

If a file does not yet exist, you can create one with the touch() function.

 
<?
touch("myfile.txt");
?>