How to detect when an iOS app crashes

Great post on StackOverflow about detecting when an app is killed, due to an exception, a signal, etc.

Most crashes can be caught using a 3-fold approach:

1. appWillTerminate
2. exception handler
3. signal handler

This translates into using:

// installs HandleExceptions as the Uncaught Exception Handler
NSSetUncaughtExceptionHandler(&HandleExceptions);
// create the signal action structurestruct sigaction newSignalAction;
// initialize the signal action structure
memset(&newSignalAction,0,sizeof(newSignalAction));
// set SignalHandler as the handler in the signal action structure
newSignalAction.sa_handler =&SignalHandler;
// set SignalHandler as the handlers for SIGABRT, SIGILL and SIGBUS
sigaction(SIGABRT,&newSignalAction, NULL);
sigaction(SIGILL,&newSignalAction, NULL);
sigaction(SIGBUS,&newSignalAction, NULL);

and:

-(void)applicationWillTerminate:(UIApplication*)application {
   ...
}
void HandleExceptions(NSException*exception){
DebugLog(@"This is where we save the application data during a exception");
// Save application data on crash
}
void SignalHandler(int sig) {
DebugLog(@"This is where we save the application data during a signal");
// Save application data on crash// Write your code to reset brightness
}

My own answer to the same question, did not go as far as suggesting to intercept signals, but that is fundamental.

As I said, really great tip!