pause - wait for signal
pause() causes the calling process (or thread) to sleep until a signal is delivered that either terminates the process or causes the invocation of a signal-catching function.
pause() returns only when a signal was caught and the signal-catching function returned. In this case, pause() returns -1, and errno is set to EINTR.
|EINTR||a signal was caught and the signal-catching function returned.|
POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD.