my $re = qr(
    (
        (?:[a-z][a-z0-9+-.]*)
        ://
        (?:
            (?:
                [a-z0-9._~!:;=&'\$\(\)\*\+\-\,]+@
            )?
            (?:
                \[${ipv6}\]
                | ${ipv4}
                | [a-z0-9._~!;=&'\$\(\)\*\+\-\,]+
            )
        )
    )
)xi;

foreach ($ARGV[0]) {
    open my $fh, '<', $_ or die("Error opening file $_.\n");
    while (my $row = <$fh>) {
        chomp $row;
        next if $row eq "";
        if ($row =~ $re) {
          print "$1\n";
        }
    }
    close($fh);
}