The Executable

The executable file of your application resides at the top-level folder of the application bundle. It must carry executable permissions to run properly and must be authenticated by SpringBoard, the iPhone’s version of Finder. Starting with firmware 1.2, which was released only to developers, SpringBoard instituted a watchdog feature to prevent arbitrary code execution. This feature put a damper on the use of command-line utilities that you find on other UNIX platforms. SpringBoard’s watchdog feature also added memory utilization limits. The system shuts down any process that uses too many system resources.