The screen terminal utility allows for the continous running of terminal jobs - even when the user is logged out:

1. Start a new session with screen.
2. Dettach screen: control-a, d
3. List all screens: screen -list
4. Re-attach screen: screen -r

• Remove dead screen: screen -wipe

Use case: WP-CLI

Ok, a bit late to the party. Apple officially approved the use of UIGetScreenImage().

After carefully considering the issue, Apple is now allowing applications to use the function UIGetScreenImage() to programmatically capture the current screen contents. The function prototype is as follows:

CGImageRef UIGetScreenImage(void);

https://devforums.apple.com/message/149553

How to caputure a view, ideally the live input of the camera? Unfortunaly there's no clean and clear interface for that. Only the undocumented UIGetScreenCapture() call:

http://www.iphonedevsdk.com/forum/iphone-sdk-development/11219-screenshots-we-allowed-use-uigetscreenimage.html

http://stackoverflow.com/questions/1531815/takepicture-vs-uigetscreenimage

http://svn.saurik.com/repos/menes/trunk/iphonevnc/iPhoneVNC.mm

http://blogs.oreilly.com/iphone/2008/10/creating-a-full-screen-camera.html

But since UIGetScreenCapture() is an undocumented call (in 3.1), here are official ways to get the content of a view.

UIGraphicsGetImageFromCurrentImageContext();

http://icodeblog.com/2009/07/27/1188/

http://www.elrepositorio.com/?p=31