perl - 我如何向 fork 的 child 发出信号以终止在 Perl 中？

Question

如何在 fork 进程之间共享相同的变量？或者我是否需要写入父文件中的文件，然后在文件存在后读取保存到子文件中的值？ $something 似乎从未在此设置，因此它只是在 sleep 中循环

my $something = -1;
&doit();
sub doit
{

 my $pid = fork();
 if ($pid == 0)
 {
      while ($something == -1)
      {
         print "sleep 1\n";
         sleep 1;
      }
      &function2();
 }
 else
 {
     print "parent start\n";
    sleep 2;
    $something = 1;
    print "parent end: $something\n";
 }
}

sub function2 {
   print "END\n";
}

Answer 1

perldoc -f fork :

File descriptors (and sometimes locks on those descriptors) are shared, while everything else is copied.

另见 Bidirectional Communication with Yourself在 perldoc perlipc .

更新:转念一想，你想要这样的东西吗？

#!/usr/bin/perl

use strict;
use warnings;

my $pid = fork;

die "Cannot fork: $!" unless defined $pid;

if ($pid == 0) {
    print "Child start\n";
    my $end;
    local $SIG{HUP} = sub { $end = 1 };

    until ($end) {
        print "Sleep 1\n";
        sleep 1;
    }
    function2();
}
else {
    print "Parent start\n";
    sleep 5;
    kill HUP => $pid;
    waitpid($pid, 0);
}

sub function2 {
    print "END\n";
}

输出:

C:\Temp> w
Parent start
Child start
Sleep 1
Sleep 1
Sleep 1
Sleep 1
Sleep 1
END