Re: Any one know how to use sigtrap with moose?

[tobyink]

in reply to Any one know how to use sigtrap with moose?

This bit:

      my $self_term=shift;
      my $self=shift;

... seems to be assuming that your handler will be called with two arguments, the second of which is an object.

But if you read sigtrap which refers you to perlvar you'll see that for real signals (not Perl's internal __DIE__ and __WARN__ signals) the handler gets passed just one parameter: the name of the signal (e.g. "INT", "QUIT", etc).

The fact that you're using Moose makes no difference here.

What are you actually hoping to achieve? What's the overall reason you're installing a signal handler? If you explain that, then perhaps somebody can give you some advice about how to go about doing it.

[[e-mail]]

Hi, Thanks for the reply, I would like to put all the signal handling code in Mypackage.pm. Not sure if it's possible. If I run

$ perl test_mypackage.pl 

then run

$ ps -ef |grep perl |grep -v grep |awk '{print $2}' |xargs kill

Then end{} should print it's status.

[Corion]

If you want some code to run at the end of your program, consider using an END block or an object destructor instead of using signal handlers. See perlsyn and/or perlobj.

[tobyink]

You could try something along the lines of:

use MyPackage;
my $newest_instance;
after BUILD => sub {
  $newest_instance = shift;
};

And then in your signal handler, call:

if ($newest_instance) {
  $newest_instance->status("killed");
  $newest_instance->end;
}

Note that if there is more than one object of class MyPackage knocking around, this will only set the status on the newest (i.e. most recently constructed) object.

Depending on exactly what you're doing, and how many instances of MyPackage you expect to exist in the lifetime of a process, you may need something else.

[Corion]

This approach will also keep $newest_instance around until the end of the program, which may or may not be what the OP intended.

[[e-mail]]

Very smart! That's exactly what I'm looking for! Thanks! But the "after BUILD" part does not work, it complains about

The method 'BUILD' was not found in the inheritance hierarchy for Mypackage at /usr/lib/perl5/Class/MOP/Class.pm line 1053

So I changed to :

sub BUILD{
  $newest_instance = shift;
}

Then it works. may be I miss some perl modules...