No, it's not true, I was lying earlier. (<-- joke)
An "ISO file" or "disk image" is just a filesystem inside a file, cat and dd will both just make a "raw copy" of anything, here are some example uses (Not very useful, just proof of concept):
Make a floppy image and write put it to another floppy
# cat /dev/fd0 > floppy.img
# cat floppy.img > /dev/fd1
Copy a partition:
# cat /dev/ad0s1a > /dev/ad1s1a
Copy CDROM to disk and mount it
# cat /dev/acd0 > /dev/ad0s1d
# mount_cd9660 /dev/ad0s1d /mnt/cdrom
"Secure" erase a disk
# cat /dev/random > /dev/ad0
Make a backup
# cat /dev/ad0 | gz > backup.img.gz
__________________
UNIX was not designed to stop you from doing stupid things, because that would also stop you from doing clever things.
|