Signal Handling

Mike Ash:

Using the low level sigaction to handle signals makes life unbelievably hard, as the signal handler is called in such a way as to place extreme restrictions on the code it contains. This makes it almost impossible to do anything useful in such a signal handler.

The best way to handle a signal in almost every case is to use GCD. Signal handling with GCD is easy and safe. On the rare occasions where you need to handle signals, GCD lets you do it with just a few lines of code.