in reply to •Re: Catching signals
in thread Catching signals

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";

[download]

Replies are listed 'Best First'.
•Re: Re: •Re: Catching signals
by merlyn (Sage) on Sep 04, 2002 at 18:26 UTC
    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?

[reply]
[d/l]
[select]
        Hi,

        I realize that this is not necessarily the answer to the question I was orignially asking, but it certainly is a solution to my problem (see the parent node). The problem was that I could not have a responsive Tk GUI running in parallel with a blocking socket read (Tk::fileevent under Win32 is broken - at least on perl 5.6.1 - I think it should be fixed by 5.7 or 5.8). Well, FYI, here's a hack that works.

        use IO::Socket;
use IO::Select;
use Tk;
use strict;

my $mw = MainWindow->new;
my $text = $mw->Text->pack();
my $button = $mw->Button(-text=>"quit",-command=>sub{exit;})->pack;
my $sock = IO::Socket::INET->new(
    Listen    => 5,
    Reuse     => 1,
    LocalPort => 7076,
    Proto     => 'tcp',
) or die "Couldn't open socket: $!";

my $sel = IO::Select->new;
$sel->add($sock);
$mw->repeat(50 => \&read_sock);

MainLoop;

sub read_sock {

  my(@ready) = $sel->can_read(0);
  return if $#ready == -1;

  my $line;
  my $new_sock = $sock->accept();
  $line = <$new_sock>;
  $text->insert('end',"$line\n");
}

        [download]
[reply]
[d/l]

In Section Seekers of Perl Wisdom