# MAIN

my $fn = shift;

try {
  safe_open($fn);
};

if ($@) {
  # here, print fatal error
  fatal_error($@);
}

# SUBS
sub safe_open {
    my $fn = shift;
    my $fh = do { local *FH };
    my ($mode, $result);

    # reset the do_trun variable.
    # and also, make it local to this sub.. why keep it global? ;)
    my $do_trun;

    if ($fn =~ /^>[^>]/) {
        $mode = 1;
    }
    elsif ($fn =~ /^>>/) {
        $mode = 2;
    }

    if ($mode == 1 and $flock_enabled) {
        # Write mode with flock.
        $do_trun = 1;
        sysopen($fh, $fn, O_CREAT | O_WRONLY)
           or die "Failed to open '$fn' in write mode with flock.";
    }
    elsif ($mode == 1) {
        # Write mode without flock.
        open($fh, ">$fn")
          or die "Failed to open '$fn' for writing (no flock).";
    }
    elsif ($mode == 2) {
        # Append mode.
        open($fh, ">>$fn")   
         or die "Failed to open '$fn' for appending.";
    }
    elsif (!$mode) {
        open($fh, $fn);
          or die "Failed to open '$fn'."; 
    }

    if ($flock_enabled) {
      flock($fh, 2) or die "Failed to flock '$fn'.";
    }

    if ($do_trun) {
      truncate($fh, 0) or die "Could not truncate file $fn.";
    }

    return $fh;
}

##</code><code>##

# Under Construction