it works but the messages are too long.

I do not know if I can change the text of the variable $!?

This script will be integrated into nagios later with nsclient and nrpe so the messages have be short.

In my reply above using eval, you can trap and then reword the errors as you see fit. Here's a short example.

eval {
    open my $fh, '<', 'asdf' or die $!;
};

if ($@ =~ /No such file or directory/){
    print "short error msg\n";
    # or...
    die "short msg";
}
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