sub safe_open {
    my $fn = shift;
    my $fh = do { local *FH };
    my ($mode, $result);
    if ($fn =~ /^>[^>]/) {
        $mode = 1;
    }
    elsif ($fn =~ /^>>/) {
        $mode = 2;
    }

    if ($mode == 1 and $flock_enabled) {
        # Write mode with flock.
        $do_trun = 1;
        $result = sysopen($fh, $fn, O_CREAT | O_WRONLY);    
    }
    elsif ($mode == 1) {
        # Write mode without flock.
        $result = open($fh, ">$fn");
    }
    elsif ($mode == 2) {
        # Append mode.
        $result = open($fh, ">>$fn");
    }
    elsif (!$mode) {
        $result = open($fh, $fn);
    }
    unless ($result) {
        # Open failed.
        fatal_error("Couldn't open $fn.");
    }
    flock($fh, 2) if $flock_enabled;
    truncate($fh, 0) or fatal_error("Could not truncate file $fn.") if
+ $do_trun;
    return $fh;
}
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Edit kudra, 2002-06-15 Added READMORE