modify $!

Ok, I've done a bit of experementation, with no sucess... Is there a way to set $! to a string to send an error back?

I'm writing a small library so to speak... and I want people to be able to use things like this


$var = mysub($othervar) || die($!)

Is it possible at all?

perlvar says:

If used in a numeric context, yields the current value of errno, with all the usual caveats. (This means that you shouldn't depend on the value of $! to be anything in particular unless you've gotten a specific error return indicating a system error.) If used in a string context, yields the corresponding system error string. You can assign to $! to set errno if, for instance, you want "$!" to return the string for error n, or you want to set the exit value for the die() operator.

I had already read that... but I couldn't make any sense of it... and I still can't...

I don't really get what you're asking. Why not just do this?



I use this everywhere and it works beautifully for me.

Ok... mabey an example of what I tried will make it obvious...


sub mysub {
if(!shift){
my ($package, $file, $line) = caller;
$! = "Error on line $line of $package in $file: Failed to pass true value";
return;
}else{
return "That was true!";
}
}

sub dienice {

print shift;
exit;

}

Now, of course thats a worthless sub, but I want to be able to SET $! like that...

so that if someone did this:

$myvar = mysub(0) || dienice($!);

It would spit out something resembling this:

Error on line 4 of somepackage in myfile.pl: Failed to pass true value


Note: All code there was thrown together and probably would NOT execute properly...

I hope that helped explain my goal...