IgnoreSignals disables the signal handler and prevents Run from being executed automatically.

OnError registers fn with atexit and returns a function which runs fn() if *perr != nil and deregisters fn It should be used in a defer statement normally so defer OnError(&err, cancelFunc)() So cancelFunc will be run if the function exits with an error or at exit.

Register a function to be called on exit.

Run all the at exit functions if they haven't been run already.

Signalled returns true if an exit signal has been received.

Unregister a function using the handle returned by `Register`.