But I think my concern about the call stack still stands. How can a single global handler be enough?

UPDATE: To clarify, here's an example of how $SIG{__DIE__} doesn't behave the way I think I would need it to:

sub catcher {
    local $SIG{__DIE__} = sub { print "Caught 1!\n"; };
    catcher2();
}

sub catcher2 {
    local $SIG{__DIE__} = sub { print "Caught 2!\n"; };
    sub_that_dies();
}

sub sub_that_dies {
    die "Foo";
}

catcher();
[download]

Now, I'd like that code to print both "Caught 1!" and "Caught 2!". But what it actually does is less useful:

$ perl bomb.pl 
Caught 2!
Foo at bomb.pl line 30.
[download]

Does that make it clear what I mean?

-sam

Well I was a bit hasty in calling it recursion, as it isn't really.

So actually you want the opposite (in a manner of speaking) of what you said, you wish to artificially enforce inheritance of die as *exceptions*. The code you give does exactly what it is supposed to, there is no die called within catcher, and $SIG{__DIE__} is re-localed to the catcher2 scope.

I think Exception::Class is what you want for that. Alternatively, here's some ugly code

local @stack;
$SIG{__DIE__} = sub { die(@stack, @_); };
catcher();

sub catcher {
    local @stack = (@stack, "Caught 1!\n");
    catcher2();
}

sub catcher2 {
    local @stack = (@stack, "Caught 2!\n");
    sub_that_dies();
}

sub sub_that_dies {
    die "Foo";
}
[download]

If, on the other hand, you actually want what's in yor original code, which is just to do something before (outter) dieing then I stand by the original suggestions, and also add END to the list; END output comes last though.

#=begin a
require 'b';
print "Hello World\n";
#This die can also be replaced with print && exit
$SIG{__DIE__} = sub { print "BOB!\n"; die(@_); };
a::a();
END{ print "Waka waka\n";
#=end a
#=begin b
package a;
sub a{
die("A!"); }
1;
#=end b
__END__
Hello World
BOB!
A! at /tmp/b line 3.
Waka waka
[download]

--
perl -pew "s/\b;([mnst])/'$1/g"

You're probably correct that what I want are exceptions, but I don't think I can get them. I'm writing a profiler and it's supposed to work with a wide range of code, most of which will be using straight die()s.

Thanks for the help!
-sam