for my $devitem (@dev_list) {
    print "Looking for $devitem\n";
    for my $xrefitem (@xref) {
        if ($xrefitem =~ /$devitem/i) { #Do you really need to match another character?
            #What's the next line for?
            # $templine=join "_","\@dev_xref",$dev_list[$i];
            my @{$templine}[0]=$xrefitem;
    }
}