If I mount an iso image, make some changes to it, and unmount it.... Is it still a valid .iso image? can I still burn it onto a cd w/ the same functionality as before, or do I need to do mkisofs on it again?

AFAIK you can't modify iso's like changing stuff because of the way stuff like TOC's are handled.

ooh darn.

thanks

They are usually tagged as readonly CD-ROM filesystems, so you won't be
able to mount them rw. . .

Is there any way to change this? I would find it incredibly helpful to be able to mount an ISO image of a *ahem* certain type of *ahem* CD so that I can add a text file that contains *ahem* certain serial informations *ahem*.

As was said before most of the filesystems on CDs are designed to be read-only. Ignoring the questionable ethics, I will assume this is for software the you legitimately own and want a working copy for. Being a programmer who makes his living selling software I have strong opinions on the subject.

That said, why not just burn your copy and place the serial # on the label?

Chances are adding a file and creating a new iso will be no more harmful to the copy than cereating the iso itself. ISO images do not specify the physical topology of the end result.

If the software is designed to a specific physical topology then a copy from an iso image would not be valid, you would need to do a raw write from a manufactured CD.

If the software is not designed for such copy protections then (purposely flawed data, specific file topology, etc) adding a file and creating a new image will not hurt anything.

EDIT: To clarify for the original poster, no it can not be done for most iso file systems. I could be wrong though.

every tried making another iso of just the text file and appending it to a cd? Or do you just want the iso as one file, so "you" can download it over the "L"AN?

"I" am not trying to send anything over a "L"AN.... I have simply made a boot cd with a program on it to install some packages.... It doesn't work right, so I need to fix it. I was wondering if I could do that without having to copy it all over to a directory again.

what do you mean by making an iso of the text file and appending it to the cd... how would you do that?

adam_boz, wasn't trying to insinuate anything dude, I was simply reacting to one of the messages in the thread before I realized it was not from you.

That said I did a quick scan of the man page for mkisofs and came up with this:

-M path
or

-M device
Specifies path to existing iso9660 image to be merged.
The alternate form takes a SCSI device specifier that
uses the same syntax as the dev= parameter of cdrecord.
The output of mkisofs will be a new session which
should get written to the end of the image specified in
-M. Typically this requires multi-session capability
for the recorder and cdrom drive that you are attempt-
ing to write this image to. This option may only be
used in conjunction with the -C option.


This is intended for multisession disks but it might do what you want.

Edit: But if you need to modify an existing file then copying the dir tree and creating a new iso is likely necessary.

No harm done.... I understand (and respect) your views on the subject.

I really don't use any closed source software, but that's probably b/c I don't do anything too important :-)

uh-oo... now I've probably pissed off a bunch of gnu gurus ;-)

really though, this is a pretty interesting topic... thanks all for your replies.