How to read CD with read?

[vishal.chauhan]

Hi All,

I m using Qt 4.1.5 on my MAC.
I am using the following code to read the HardDisk or any other Drive.

fileDescriptor = open ( DriveName, O_RDONLY );	
lseek(fileDescriptor,(off_t) SectNo*SECTSIZE, SEEK_SET);	
numBytes = read( fileDescriptor, Buffer, Size );

fileDescriptor = open ( DriveName, O_RDONLY );	
lseek(fileDescriptor,(off_t) SectNo*SECTSIZE, SEEK_SET);	
numBytes = read( fileDescriptor, Buffer, Size );

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where for disk I have Drive Name as /dev/rdisk0.

But if I read CD by the above code it is returning non negative value in fileDescriptor and lseek also working right but in the read function is is returning -1.


If some one know why it is not working with CD then plz help me.


Thanks.

[wysota]

Do you want to read files or the raw ISO? Reading from /dev/cdrom or similar should work fine... Provided you have permissions to do that.

[vishal.chauhan]

Thanks for Reply.

Actually I want to read raw ISO.

I think I have permission because when I open the CD with
fileDescriptor = open ( DriveName, O_RDONLY );
it return 14 that it is opening the file but problem is when I read the disk it is returning -1.

[wysota]

Is the disk mounted at that time?

[vishal.chauhan]

Yes. It is showing it in the Finder and I can see the Conetnts of it.

[wysota]

Can you unmount it and try again?

[vishal.chauhan]

Thanks.

Now I m able to do it.

Actually I m reading from disk by adding r before disk as /dev/rdisk0 but to CD I have just have to read like /dev/disk2.

Thanks for Reply.