Re: what is rationalized rock ridge directory information?

[Thomas Schmitt]

Hi,

Karl Berry wrote:
> xorriso --as mkisofs --help says:
>   -r, -rational-rock          Generate rationalized Rock Ridge directory
> information
>
> What is this?

The wording of the help text line is as in mkisofs, in order to give
programs a chance to look for availability of -r. So i guess it was
coined by Joerg Schilling.

I would dispute the appropriateness of the term "rational", as -r is
devastating if the ISO is made for the purpose of disk backup rather than
of mastering a distribution medium.


> The word "rational" does not appear in the xorriso Texinfo
> manual, as far as I could see. A mention would be nice.

xorriso -as mkisofs has its own info document (and man page):

  info xorrisofs

which says

  -r
     Enable Rock Ridge and set user and group id of all files in the ISO
     image to 0.  Grant r-permissions to all.  Deny all w-permissions.
     If any x-permission is set, grant x-permission to all.  Remove
     s-bit and t-bit.
     These attribute changes stay delayed until mkisofs emulation ends.
     Within the same -as mkisofs emulation command they can be revoked
     by a subsequent option --norock.  For compatibility reasons, option
     -R does not revoke the changes ordered by -r.
  -rational-rock
     Alias of -r.

The xorriso command equivalent is

  -find / -exec mkisofs_r --

Described in info xorriso by

  -find iso_rr_path [test [op] [test ...]] [-exec action [params]] --
       A restricted substitute for shell command find in the ISO image.
       It performs an action on matching file objects at or below
       iso_rr_path.
       ...
       mkisofs_r
            applies the rules of mkisofs -r to the file object:
            user id and group id become 0, all r-permissions get granted,
            all w denied.  If there is any x-permission, then all three x
            get granted.  s- and t-bits get removed.


There is also a specialized  info document (and a man page) for
xorriso -as cdrecord :

  info xorrecord


Have a nice day :)

Thomas