问题描述
对于网站，我需要能够启动和停止守护进程.我目前正在做的是
For a website, I need to be able to start and stop a daemon process. What I am currently doing is
exec("sudo /etc/init.d/daemonToStart start");
守护进程已启动，但Apache/PHP挂起.进行ps aux显示sudo本身变成了僵尸进程，有效地杀死了所有进一步的进程.尝试从PHP启动daeomon时，这是正常现象吗?
The daemon process is started, but Apache/PHP hangs. Doing a ps aux revealed that sudo itself changed into a zombie process, effectively killing all further progress. Is this normal behavior when trying to start a daeomon from PHP?
是的，Apache有权执行/etc/init.d/daemonToStart命令.我更改了/etc/sudoers文件以允许它这样做.不，我不允许Apache执行任何类型的命令，只有少数几个可以使网站正常工作.
And yes, Apache has the right to execute the /etc/init.d/daemonToStart command. I altered the /etc/sudoers file to allow it to do so. No, I have not allowed Apache to be able to execute any kind of command, just a limited few to allow the website to work.
无论如何，回到我的问题，有没有一种方法允许PHP以不创建任何僵尸进程的方式启动守护进程?我之所以这样问，是因为当我做相反的事情时，停止一个已经启动的守护进程就可以了.
Anyway, going back to my question, is there a way to allow PHP to start daemons in a way that no zombie process is created? I ask this because when I do the reverse, stopping an already started daemon, works just fine.
推荐答案
尝试将> /dev/null 2>&1 &附加到命令中.
所以这个:
exec("sudo /etc/init.d/daemonToStart > /dev/null 2>&1 &");
以防万一，您想知道它的作用/原因:
Just in case you want to know what it does/why:
-
> /dev/null-将STDOUT重定向到/dev/null(换句话说，它是黑洞的) -
2>&1-将STDERR重定向到STDOUT(也将其黑洞) -
&分离过程并在后台运行
> /dev/null- redirect STDOUT to /dev/null (blackhole it, in other words)2>&1- redirect STDERR to STDOUT (blackhole it as well)&detach process and run in the background
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