MacBook-Pro-di-Emanuele:~ Emanuele$ hdiutil convert-format UDRW Is Download/ubuntu.iso -o Is Documenti/ubuntu.img
hdiutil: convert-format: verb not recognized
Usage: hdiutil <verb> <options>
<verb> is one of the following:
help            	flatten
attach          	imageinfo
detach          	internet-enable
eject           	isencrypted
verify          	makehybrid
create          	mount
compact         	mountvol
convert         	unmount
burn            	plugins
info            	resize
checksum        	segment
chpass          	pmap
erasekeys       	udifderez
unflatten       	udifrez
MacBook-Pro-di-Emanuele:~ Emanuele$