use Fcntl ':flock';
use Tie::File;
sub reordermenu {
    # set $info{'m_id'), $m_action somehow
    # from parameters passed to this. Think
    # of a better data structure.

    my $df = tie my @menuitems, 'Tie::File',
        "$datadir/defaults/menu.dat";
    $df->flock(O_EXCL);

    my @indexes = grep {
        $info{'m_id'} eq (split /\|/, @menuitems[$_], 2)[0]
    } 0 .. $#menuitems;

    for (@indexes) {
        my $tondx = $m_action eq 'moveup' ?
                        $_ ? $_-1 : $_ :
                        $_ == $#menuitems ? $_+1 : $_;
        @menuitems[$_, $tondx] = @menuitems[$tondx, $_];
    }
    untie @menuitems;
    1;
}