Re: Error Handling Misconception

[bobn]

if the eval fails, it your function probably also returned a false value, which caused your while loop to skip the if ( $@ ) code.

--Bob Niederman, http://bob-n.com

All code given here is UNTESTED unless otherwise stated.

[Anonymous Monk]

Thanks for the suggestion. That doesn't seem to be it, though: I still get the program dying w/o error if I do just this:

my $value = eval { $object->next_value() };

if ($@) { print "BLAH!\n"; }
print $value, "\n";

...and no output to screen.

[bobn]

works for me:

my $object = new wierd;
my $value = eval { $object->next_value() };

if ($@) { print "BLAH!\n$@\BLAH!\n"; }
print $value, "\n";

package wierd;

sub new { bless {}, shift}

sub next_value
{
    die "badness";
}

Produces:

BLAH!
badness at ./tstprog.pl line 13.
BLAH!

Are you sure you're in a situation where you can see what's printed? What happens when the routine works and $value is something printable?

--Bob Niederman, http://bob-n.com

All code given here is UNTESTED unless otherwise stated.

[Anonymous Monk]

I feel stupid...

Are you sure you're in a situation where you can see what's printed? What happens when the routine works and $value is something printable?

Once I took it out of CGI and put it in a text-file to get the minimum error, it worked. There's a bug somewhere in my CGI that I'll have to track down, but this is working fine now. Thank you muchly.

[selk]

Make sure a header goes out to the browser before the die message. If your code dies before it had the chance to print the header, then you will likely get an error. I susally just do this at the beginning of my cgi:

print "Content-type: text/html\n\n";

Hope that helps,
selk