caffeinate under lion 10.7.4
"To use the caffeinate command you’ll need to be running a fairly modern version of OS X, as the feature was introduced in 10.8 Mountain Lion and persists through 10.9 Mavericks, and into 10.10 Yosemite.
Heads up to MacWorld for the tip."
Source: http://osxdaily.com/2012/08/03/disable-sleep-mac-caffeinate-command/

Alternative to caffeinate:
http://lifehacker.com/5767991/how-to-force-your-mac-to-stay-awake-indefinitely-via-the-command-line
Thus work for me!