如何捕获KILL或HUP或用户中止信号？

Question

我有一个脚本在我的linux服务器的后台运行,我想捕获像重启或任何会杀死这个脚本的信号,而是在实际退出之前保存任何importante信息.

我认为我需要捕获的大部分内容是SIGINT,SIGTERM,SIGHUP,SIGKILL.

如何捕获这些信号并使其执行退出功能,否则继续执行它正在执行的任何操作？

伪perl代码:

#!/usr/bin/perl

use stricts;
use warnings;

while (true)
{
    #my happy code is running
    #my happy code will sleep for a few until its breath is back to keep running.
}

#ops I have detected an evil force trying to kill me
#let's call the safe exit.
sub safe_exit() 
{
    # save stuff
    exit(1);
}

伪PHP代码:

<?php

while (1)
{
    #my happy code is running
    #my happy code will sleep for a few until its breath is back to keep running.
}

#ops I have detected an evil force trying to kill me
#let's call the safe exit.

function safe_exit()
{
    # save stuff
    exit(1);
}
?>

Answer 1

PHP用于pcntl_signal注册信号处理程序,如下所示:

declare(ticks = 1);

function sig_handler($sig) {
    switch($sig) {
        case SIGINT:
        # one branch for signal...
    }
}

pcntl_signal(SIGINT,  "sig_handler");
pcntl_signal(SIGTERM, "sig_handler");
pcntl_signal(SIGHUP,  "sig_handler");
# Nothing for SIGKILL as it won't work and trying to will give you a warning.

Answer 2

Perl的:

@SIG{qw( INT TERM HUP )} = \&safe_exit;

SIGKILL无法被抓住.它不会发送到进程.

%SIG记录在perlvar中.另见perlipc