We’ve provided a couple of tips to help you prevent your Mac from going to sleep when you don’t want to, from a time-based app called Sleep No More to some Terminal magic that can do something similar. Unfortunately, both solutions are based on time. What if you want to keep your Mac from sleeping while it’s running a specific app, no matter how long it takes?
Free Mac app, Wimoweh, may be your answer. Check it out.
Download Wimoweh from the Mac App Store and let it install on your Mac. Launch it from Launchpad or the Applications folder to get it started. Once launched, click on the Lion head icon in your menu bar.
You’ll have a couple of options, then. Select the “Never Sleep Whilst Running…” option to pick a currently running app. As long as that app continues to run, your Mac won’t go to sleep. Easy, right?
Now, select Prevent Computer Sleep from the Wimoweh menu. This is like a toggle for the No Sleep feature or Wimoweh, and it will allow your Mac to run, unslept, as long as you keep it enabled. Notice that you can now choose the Apps Preventing Sleep option from the Wimoweh menu, now, to be told that Wimoweh is indeed preventing your Mac from sleeping.
Use Wimoweh cautiously when running a laptop on battery power, obviously, as your battery will drain much faster if your Macbook never sleeps..