- str_repeat: documentation ( source)
- preg_match: documentation ( source)
- preg_last_error: documentation ( source)
<?php
$subject = str_repeat('a', 5431);
$res = preg_match('~(a)*~', $subject);
if ($res > 0) {
echo 'match', PHP_EOL;
} elseif ($res === 0) {
echo 'no match', PHP_EOL;
} else {
echo 'preg_match error ', preg_last_error(), PHP_EOL;
}