php信号处理

<?php
$catch_quit_signal = 0;
function sig_handler($signo)
{
    global $catch_quit_signal;
    switch ($signo) {
        case SIGINT:
        case SIGTERM:
        case SIGHUP:
        case SIGQUIT:
        case SIGTSTP:
            $catch_quit_signal = $signo;
            break;
        default:
    }
}
pcntl_signal(SIGINT, 'sig_handler');
pcntl_signal(SIGTERM, 'sig_handler');
pcntl_signal(SIGHUP, 'sig_handler');
pcntl_signal(SIGQUIT, 'sig_handler');
pcntl_signal(SIGTSTP, 'sig_handler');
declare(ticks=1);