An array of, say, strings, or functions, indexed according to IPC signal numbers. So array[SIGHUP] would be the same as array[2] so SIGILL would be array[4], or

An array of, say, strings, or functions, indexed according to IPC signal numbers. So array[SIGHUP] would be the same as array[2] so SIGILL would be array[4], or the 5th element of the array.