perl next, last, regular expression 實用場景

#!/usr/local/bin/perl -w
use strict;
use v5.10;

my $torrent = shift;

foreach ( `btcheck -li 2>/dev/null $torrent` ) {
        /Torrent Hash : ([a-f0-9]{40})$/i;
        next unless $1;
        chomp $1;
        say "magnet:?xt=urn:btih:$1";
        last;
}

btcheck -li 2>/dev/null $torrent

無法在tcsh中執行，因為redirection 2>/dev/null在tcsh中不支援。只能在bash中執行