__DIE__ easy CGI question

datannen has asked for the wisdom of the Perl Monks concerning the following question:

I am simply trying to get an error code to pass to a redirected page. Basically, I want "3" to become part of the redirect for my __DIE__

My code is as follows:

        $sqlquery = "SOME UPDATE STATEMENT";
        my $newsth = $dbh->prepare($sqlquery);
        $newsth->execute or die "3";
[download]

and the DIE handler...

$SIG{__DIE__} = sub {
  print $query->redirect(-location=>"$redirecturl?error=@_");
};
[download]

How do I get the "3" to pass to my redirect?

Comment on __DIE__ easy CGI question Select or Download Code

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Re: __DIE__ easy CGI question by batkins (Chaplain) on Sep 30, 2003 at 01:46 UTC
I'm not sure if a __DIE__ handler is the best way to go. I would use an eval block to trap the die. Something like this: `eval { $sqlquery = "SOME UPDATE STATEMENT"; my $newsth = $dbh->prepare($sqlquery); $newsth->execute or die "3"; }; print $query->redirect(-location=>"$redirecturl?error=$@") if $@;` [download] When the die is called, the eval block will exit and $@ will be set to "3". If there is no error, then $@ will be set to the empty string. If I were a terrorist I'd mainly be afraid of polar bears. Because at the moment, I'm mainly afraid of polar bears, and I can't really see why that would change. - slashdot	[reply] [d/l]
Re: __DIE__ easy CGI question by sgifford (Prior) on Sep 30, 2003 at 03:07 UTC
The code you have looks about right. This works OK: `#!/usr/bin/perl -w use strict; $SIG{__DIE__} = sub { print "redirecturl?error='@_'\n"; exit(1); }; die "3";` [download] produces: redirecturl?error='3 at /tmp/t112 line 10. ' The problem is that you also get a line number with your error message. You can either eliminate that with a regex, or you can use `die "3\n"` and then use `chomp` to eliminate the newline. The `@_` variable is readonly, so you'll have to make a copy: `#!/usr/bin/perl -w use strict; $SIG{__DIE__} = sub { my $why = shift; $why =~ s/( at.*)?\n$//; print "redirecturl?error='$why'\n"; exit(1); }; die "3";` [download] produces redirecturl?error='3' whether you use `die "3"` or `die "3\n"`.	[reply] [d/l] [select]