in reply to Catching signals

use strict;

my $pid = fork();
if ($pid) {
  print "I am parent $$\n";
  kill INT => $pid;
  print "I am parent $$\n";
} elsif (defined($pid)) {
  print "I am child $$\n";
  local $SIG{INT} = sub { die "\nOutta here!\n" };
  print "I am child $$\n";
  exit 1;
} else {
  print "child was not created\n";
}

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The child isn't hanging around much. I wouldn't be surprised if you never got the "Outta here" message.

You'll want the child to block. Add sleep 30 or something, after setting up the $SIG{INT}.

-- Randal L. Schwartz, Perl hacker

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Re: •Re: Catching signals
by Anonymous Monk on Sep 04, 2002 at 18:13 UTC
    As I have replied to RMGir, i have tried making those corrections already and they don't seem to work. To clarify, here's the adapted code. I still don't see the handler message.
    use strict;
use sigtrap 'handler' => \&myhand, 'INT';

sub myhand{ print "\nOutta here $$!\n" };

my $pid = fork();
if ($pid) {
  print "I am parent $$\n";
  for (1 .. 1000000){}
  kill INT => $pid;
  print "I am parent $$\n";
} elsif (defined($pid)) {
  print "I am child $$\n";
  while (1){
    sleep 1;
  }
} else {
  print "child was not created\n";
}

wait();
print "hi\n";

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[d/l]
      Ahh. That code works as expected for me. The signal handler is called in both the parent and the child. I had to use a ^Z to finally get out of the code.

      So, what's your perl -V look like?

      -- Randal L. Schwartz, Perl hacker

[reply]
        Please see 195144 for my answer and RMGir's reply. Is there any other work around to communicate between child and parent under win32? (this all started when a child was doing a blocking read and the parent was used to break out of that read cycle) So far, I have tried pipe $parent,$child or die, which still seemed to be blocked by that read statement. I also tried open(TO,"$-") || die but that's not supported by win32 either. I also tried threads, but activestate, in a stroke of genius, did not compile the perl.exe binary with 5005Threads, which makes the Thread.pm module useless. Instead, they compiled it with iThreads, which, even after getting threads.pm and threads::shared.pm into perl 5.6.1, do not seem to work for me (I get an error message saying that perl version is less than 5.8).

        Any other suggestions?

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