sub tail_lines {
        my ($proc,$text) = @_;

        print "tail_lines $text" if $debug;

        push @{$proc->{tailbuf}},$text;
}

sub check_log {
    my $this = shift;
    return unless exists $this->{log};

# ... other code here to do with log files

    if (exists $this->{tailbuf}) {
        my $outstr = '';
        $outstr .= shift @{$this->{tailbuf}} while @{$this->{tailbuf}};

        $this->{tailwin}->insert('end' => $outstr);
        $this->{tailwin}->see('end');
    }
}