[SOLVED] ISO Filesystem Information / Analysis Tool

unassailable · 05-13-2015, 12:32 PM

I have an ISO which is placed on a USB device and then inserted into a system in order to update it. The issue is I need to edit a file on the ISO and recreate a new image, with the original ISO's options, so that this system will recongize and use it.

I've been searching the web for a tool/method that will tell me how the ISO was "created".

Does it have a boot image or catalog
Was a boot-load-size specified
Was rock ridge used
Was a specific volid used
etc...

I've looked through mkisofs for an option that would accomplish this, but haven't seen one yet.

Does anyone have some suggestions? All of my internet queries thus far have only yielded a deluge of "what is an ISO" and "how to mount and burn an ISO" results...

unassailable · 05-13-2015, 12:36 PM

Amazing how a random thought can lead you to your answer.

Code:

qlist cdrtools

showed an 'isoinfo' binary installed. This looks like what I needed.

EDIT: The binary isodebug when given an image outputs the command used to create the image.

Code:

$ isodebug -i ISO.iso
ISO-9660 image created at Sat Jun 21 16:45:14 2014

Cmdline: '3.01a02 -r -J -o swdl.iso ISO'

JZL240I-U · 05-13-2015, 12:45 PM

Is that a command entered in a terminal? What distribution do you use? Did you try it yet? Didn't you mount the iso with the "-o loop" option and wouldn't that allow you to edit what you want?

unassailable · 05-13-2015, 12:52 PM

Quote:

Originally Posted by JZL240I-U

Is that a command entered in a terminal? What distribution do you use?

Sorry, forgot about the basics.

I'm running linux-3.18.11-gentoo x86_64 from the terminal. All these binaries are installed with the 'cdrtools' package available in the main repo.

Quote:

Did you try it yet?

Yes I did and it gave me what I needed

Quote:

Didn't you mount the iso with the "-o loop" option and wouldn't that allow you to edit what you want?

I did come across this during my searching and after looking into it I think this is a misnomer. I was able to mount it using the loop option but the filesystem is readonly due to the nature of the ISO filesystem.

yancek · 05-13-2015, 04:27 PM

Quote:

I did come across this during my searching and after looking into it I think this is a misnomer. I was able to mount it using the loop option but the filesystem is readonly due to the nature of the ISO filesystem.

Loop mounting will not allow writing to the extracted file as you indicate. You would need to copy the loop mounted directories/files to another location where you have write permissions to make changes, then re-create the iso. Moot point in your case as you have found another method.

Habitual · 05-13-2015, 05:01 PM

JZL240I-U · 05-15-2015, 11:51 AM

Quote:

Originally Posted by unassailable

...I was able to mount it using the loop option but the filesystem is readonly due to the nature of the ISO filesystem.

Hmm. Though all is solved and well, I just wonder if a "mount -o loop,rw" wouldn't have done the trick, but, as already stated, it is sort of moot

...

<edit> Tried it myself. System (openSUSE) denies rw mounting because of file system type. </edit>