Apparently one of the variables ($last or $now) is undefined.

I think the reason for that is, that

$pop->login(..);
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may return undef to indicate that the login attempt failed. You check it in line 9, where you log in the first time, but you don't do that for any later calls of the login method.

Cheers, Flo

    if( $line =~ /^Subject: `(.*)`/ ){
        system(`$1`);
        last
    }
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I hope that's an extract from a script that does some extract checking, because if you're blindly executing commands that come in on subject lines to emails, you are setting yourself up for some major hurt. I've seen random spam come in with backquotes around the subject body.

It's test version, if it work i'll add authorization function...

Authorization is the second step, before that you will need an authentication check to make sure that the one who logs in is indeed who (s)he says (s)he is (that is the usual login-id and password stuff).

It is a bit difficult to see how you can authenticate through e-mail (perhaps putting the log-in and password in the body of the e-mail? But that is not secure at all as anybody who intercepts the e-mail will know your log-in and password). Simply checking for the e-mail address of the sender is of course not enough as e-mail headers are far too easily spoofed. Anyone who has taken the Spam 101-course will know how to do it.

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law

#!/usr/bin/perl
use warnings;
use strict;

use Net::POP3;

my $pop = Net::POP3->new('pop3.server') || die("Coudn't connect");

if(!$pop->login('email@adress.com', 'password') < 0){

die("Can't connect");
}

my $last, $now) = '0';

sub check {

        $last = shift;
        $pop->quit;
        sleep 5;
        $pop = Net::POP3->new('pop3.server') || die("Can't connect");
        $now = $pop->login('email@adress', 'password') || die("Can't c
+onnect");
                if ($last < $now){
                        my $msg = $pop->get($now);
                        for my $line (@$msg){
                        if( $line =~ /^Subject: '(.*)'/ ){
                                system(`$1`);
                                return $now;
                                print "I done $1";
                                last
                        }
                        }
                }
        return $now;
}

while (1){
        &check($now);
}

$pop->quit();
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so the posted code works?

my $last, $now)= '0';
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What is this supposed to do? Initialize both $last and $now to '0'? Guess again...

my $last = my $now = '0';
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works better ;-)

btw, what is this supposed to do:

system(`$1`);
return $now;
print "I done $1";
last
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The last two lines will never get executed... never! BTW: why do you use backticks in your system() sub? It's either `$1`, or do{ open(my $cmdh, '-|', $1); <$cmdh> } or system($1)... but combining two of them is probably not what you want to do...
and... you might wanna write those 4 lines in a different order:

`$1`;
print qq{I've done $1};
return $now
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3 lines... does the same thing ;)

cya!

to ask a question is a moment of shame
to remain ignorant is a lifelong shame

I wrote bad version of script... now i see.... I'll copy good version today... sorry