sub touch {
    open F, ">>$_[0]" or return undef;
    seek F, 0, 2;
    my $length = tell F;
    print F 'A';
    truncate F, $length;
    close F;
  return 1;
}

# presuming that the utime() function used in File::Touch is broken on your system
# otherwise it would just be:
utime($a, $m, $file);