Subject: Re: Long Filenames from CDROM
To: None <>
From: Bernd Sieker <>
List: netbsd-users
Date: 02/25/2000 20:23:01
On 25.02.00, 14:04:34, Frank van der Linden wrote:
> If you roasted the CDR under Windows, it will very probably have had
> its long filenames specified in the "Joliet" format. A short explanation:
> the most commonly used CD-ROM filesystem format is specified in ISO9660.
> This defines a filename format of 8.3 (8 for the name, 3 for the extension).

This is not strictly speaking 100% correct. ISO 9660 allows for longer
filenames (32 charactes iirc), but most systems can't handle them
sensibly (most notably DOS), so nearly all ISO CDs are made with short
(8+3) filenames plus RR extensions (see below). Some Amiga CD-ROMs
were made with long ISO 9660-conforming filenames, making them
unusable on DOS systems.

Another more dramatic restriction of ISO 9660 is that it limits
directory depth to 8 levels (including top-level). This problem is
also addressed by the various extensions (RR, Joliet, apple).

> Since this wasn't very suitable for Unix systems, the so-called "Rock Ridge"
> extensions were defined, that enables long filenames in a backward
> compatible way.
> Somewhere later along the line, Microsoft, being Microsoft, came up with
> its own version of long filename support, called "Joliet", which also
> contains an extension for extended character sets.
> 1.4.1 did not support the Joliet long filenames. -current (to be 1.5)
> does. Unfortunately, the patch was not pulled up into 1.4.2, I see now.
> An unfortunate oversight, it was not a that big a change.

I would imagine that there are Windows CD-R writing programs that know
about Rock Ridge extensions.

Otherwise, use mkisofs/mkhybrid and cdrecord to make the CD under

But if you have the CD-R writer at a Windows-only machine, you can
still make the ISO-image (including RR and Joliet extensions) on Unix,
using mkisofs or mkhybrid and burn the pre-made image under Windows.

> - Frank

Bernd Sieker

Unix, the solution to the W2k problem.