Editing Entry point (section)

==Exit point==
In general, programs can exit at any time by returning to the operating system or [[crash (computing)|crashing]]. Programs in interpreted languages return control to the interpreter, but programs in compiled languages must return to the operating system, otherwise the processor will simply continue executing beyond the end of the program, resulting in [[undefined behavior]].

Usually, there is not a single exit point specified in a program. However, in other cases runtimes ensure that programs always terminate in a structured way via a single exit point, which is guaranteed unless the runtime itself crashes; this allows cleanup code to be run, such as <code>atexit</code> handlers. This can be done by either requiring that programs terminate by returning from the main function, by calling a specific exit function, or by the runtime catching exceptions or operating system signals.