If you are looking for a way to mount a CD or DVD image in Mac OSX similar to the loop method in Linux like
mount -o loop /path/to/image.iso /mnt/dvd
In Mac OSX there is a similar command from BSD called hdiutil
The use is similar to the mount -o loop method shown above but lacks the control of where the image is mounted, the result is identical to OSX's mounting an image and will produce a disk image icon on the desktop which can be ejected (unmounted) as needed
hdiutil attach -readonly /path/to/image.iso
A real world example including the output is show below, note the device name it gets mounted under in your system and use this to unmount after. Note in the example below I am mounting a .dmg file which is the Macintosh equivelant of an .iso filesystem in some ways but it is not identical.
bigmac:~ neil$ hdiutil attach -readonly Desktop/Mac\ OS\ X\ Install\ DVD.dmg
Checksumming whole disk (Apple_HFS : 0)…
...............................................................................
whole disk (Apple_HFS : 0): verified CRC32 $39CE04B6
verified CRC32 $713800C0
/dev/disk4 /Volumes/Mac OS X Install DVD
hdiutil can also be called to eject the image as discussed above and show below
bigmac:~ neil$ hdiutil eject /dev/disk4
"disk4" unmounted.
"disk4" ejected.
