- array_slice: documentation ( source)
- implode: documentation ( source)
- explode: documentation ( source)
<?php
$line = '*/3 * * * * echo yes';
$parts = explode(' ', $line);
$schedule = implode(' ', array_slice($parts, 0, 5));
$command = implode(' ', array_slice($parts, 5));
print $schedule.PHP_EOL.$command;