void (*signal(int sig, void (*handler)*int)))(int);
    

valid values for sig:

      SIGABRT    abnormal termination (e.g. from abort)
      SIGFPE     arithmetic error (e.g. zero divide, overflow)
      SIGILL     illegal function image (e.g. illegal instruction)
      SIGINT     interactive attention (e.g. interrupt)
      SIGSEGV    illegal storage access (e.g. access outside memory limits)
      SIGTERM    termination request sent to this program
    

valid values for the handler

      SIG_DFL    implementation-defined behavior
      SIG_IN     signal is ignored
      otherwise  function pointed to by handler will be called