perl fork()exec()，子进程变得疯狂

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我正在使用Linux，而.sh在tcsh中.

I am using Linux and .sh is in tcsh.

我做了一个非常基本的叉子和 exec ，但在实现安全性方面我需要帮助.

I have made a very basic fork and exec, but I need help in implementing safeties to it.

基本上，我的perl脚本在子进程中调用.sh脚本.但是当我Ctrl+c杀死父母时，孩子会忽略该信号.

Basically my perl script calls a .sh script in a child process. But when I do Ctrl+c to kill the parent, the signal gets ignored by the child.

1)我如何也捕获子进程的SIGINT?

1) How do I capture the SIGINT for the child process as well?

2)运行.sh脚本的子进程仍然STDOUT到xterm的屏幕.我该如何删除?我当时正在考虑在后台运行脚本

2) The child process that runs the .sh script still STDOUT to the screen of the xterm. How can I remove this? I was thinking of doing running the script in the background

exec("shell.sh args &");

但是还没有进行测试，因为我需要弄清楚如何防止孩子先变得疯狂.

But haven't tested as I need to figure out how to keep the child from going wild first.

3)父进程(perl脚本)不等待子进程(.sh脚本).所以我读了很多关于孩子成为僵尸的信息???脚本完成后会发生吗?而我将如何停止呢?

3) The parent process(perl script) doesn't wait on the child(.sh script). So I've read a lot about the child becoming a zombie??? Will it happen after the script is done? And how would I stop it?

$pid = fork(); if($pid < 0){ print "Failed to fork process... Exiting"; exit(-1); } elsif ($pid ==0) { #child process exec("shell.sh args"); exit(1); } else { #execute rest of parent}

推荐答案

但是当我执行ctrl + c杀死父级时，子级会忽略该信号.

But when I do ctrl+c to kill the parent, the signal gets ignored by the child.

信号被发送给父母和孩子两个.

The signal is sent to two both the parent and the child.

$ perl -E' if (my $pid = fork()) { local $SIG{INT} = sub { say "Parent got SIGINT" }; sleep; waitpid($pid, 0); } else { local $SIG{INT} = sub { say "Child got SIGINT" }; sleep; } ' ^CParent got SIGINT Child got SIGINT

如果那个孩子忽略了它，那是因为它开始了一个新的会话，或者是因为它明确地忽略了它.

If that child ignores it, it's because it started a new session or because it explicitly ignores it.

运行.sh脚本的子进程仍然STDOUT到xterm的屏幕.我该如何删除呢?

The child procces that runs the .sh script still STDOUT to the screen of the xterm. How can I remove this?

在调用exec之前在孩子中执行以下操作:

Do the following in the child before calling exec:

open(STDOUT, '>', '/dev/null'); open(STDERR, '>', '/dev/null');

实际上，我会使用 open3 进行一些错误检查. /p>

Actually, I would use open3 to get some error checking.

open(local *CHILD_STDIN, '<', '/dev/null') or die $!; open(local *CHILD_STDOUT, '>', '/dev/null') or die $!; my $pid = open3( '<&CHILD_STDIN', '>&CHILD_STDOUT', '>&CHILD_STDOUT', 'shell.sh', 'args', );

父进程(perl脚本)不等待子进程(.sh脚本).所以我读了很多关于孩子成为僵尸的故事?

The parent process(perl script) doesn't wait on the child(.sh script). So I've read alot about the child becoming a zombie???

孩子在父母退出时或在父母退出后退出时会自动获得收成.

Children are automatically reaped when the parent exits, or if they exit after the parent exits.

$ perl -e' for (1..3) { exec(perl => (-e => 1)) if !fork; } sleep 1; system("ps"); ' ; ps PID TTY TIME CMD 26683 pts/13 00:00:00 bash 26775 pts/13 00:00:00 perl 26776 pts/13 00:00:00 perl <defunct> <-- zombie 26777 pts/13 00:00:00 perl <defunct> <-- zombie 26778 pts/13 00:00:00 perl <defunct> <-- zombie 26779 pts/13 00:00:00 ps PID TTY TIME CMD 26683 pts/13 00:00:00 bash 26780 pts/13 00:00:00 ps <-- all gone

如果父母先于孩子退出，那就没问题了.

If the parent exits before the children do, there's no problem.

如果父母在孩子们离开后不久就退出了，那就没问题了.

If the parent exits shortly after the children do, there's no problem.

如果父母在孩子离开后很长时间退出了，您将希望获得他们的收获.您可以使用wait或waitpid(可能来自SIGCHLD处理程序)来执行此操作，也可以使用$SIG{CHLD} = 'IGNORE';使它们自动收割.参见 perlipc .

If the parent exits a long time after the children do, you'll want to reap them. You could do that using wait or waitpid (possibly from a SIGCHLD handler), or you could cause them to be automatically reaped using $SIG{CHLD} = 'IGNORE';. See perlipc.