[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Using readcd to read 3rd party discs

> 1.isoinfo result and readcd result do not always match. Which one to
>   choose. Can readcd just tell the number of sectors without reading
>   till end?

isoinfo -d tells you the size of the filesystem. If the filesystem was
created by mkisofs, it will be accurate. In theory I guess some joker
could put a wrong number into this field, I don't know whether this
would stop things from working on winblows. You could double-check with
df after mounting the CD.

readcd by the looks of it gives you some sector number recorded in the
CD's toc. It must be >= the number given by isoinfo.

If you want to read the filesystem, use the isoinfo number. If it's a
multi-session CD, things are trickier.

> 2.Assuming I decide to use a value for number of sectors, how do I know
>   that I should subtract 2 from it (in case CD was written w/o -dao) or

You never subtract 2 from anything if it's a data CD. -tao or -dao are
irrelevant. You need to read all blocks of the filesystem, whatever is
beyond that on the CD is of no interest. The only interesting question
is "how big is the filesystem".


Volker Kuhlmann			is possibly list0570 with the domain in header
http://volker.dnsalias.net/		Please do not CC list postings to me.

Reply to: