The raise() function sends the signal sig to the executing program. It uses the kill() function to send the signal to the executing program,
See the kill(2) manual page for a detailed list of failure
conditions and the signal(3C) manual page for a list of signals.
Upon successful completion, 0 is returned. Otherwise, -1 is returned and errno is set to indicate the error.
See attributes(5) for descriptions of the following
getpid(2), kill(2), signal(3C), attributes(5)