Periodically backups a file

backupper.php

<?php
if( $argc === 1 ) {
	die('Will periodically backup a file. Usage: php ' . $argv[0] . ' filename' . PHP_EOL);
}

$filename = $argv[1];
if( !file_exists($filename) )
	die('File ' . $filename . ' not found.' . PHP_EOL);
	
$backupEverySeconds = 60*30; //backup every half hour
$lastBackup = 0;

while( true ) {
	if( (time() - $backupEverySeconds) > $lastBackup ) {
		//perform the backup
		$newFilename = $filename . date('YmdHis');
		copy($filename, $newFilename);
		$lastBackup = time();
	}
	
	sleep(180);
}