//------------------------------------------------------------------------------
// A simplified demonstration of signal handling; part 3

#include <stdlib.h>			// Libraries which may be needed
#include <stdio.h>
#include <signal.h>

struct sigaction sigaction_structure;	// A data structure, filled in below

void broken();				// Declaration only - definition below


//------------------------------------------------------------------------------

int num;				// A global variable
int *ptr;				//  and a pointer

//------------------------------------------------------------------------------

int main (int argc, char *argv[])	// The 'root' programme; execution start
{

  // Set three fields in a predefined 'struct'
  sigaction_structure.sa_handler = &broken;	// Pointer to a -function-
  sigemptyset(&sigaction_structure.sa_mask);	// Call defines 'empty' field
  sigaction_structure.sa_flags   = 0;		// No flags

  // Link the structure to signal "SIGSEGV"
  sigaction(SIGSEGV, &sigaction_structure, NULL);	// Link
  // Link the structure to signal "SIGINT"
  sigaction(SIGINT, &sigaction_structure, NULL);	// Link
  // Link the structure to signal "SIGTERM"
  sigaction(SIGTERM, &sigaction_structure, NULL);	// Link
  // Link the structure to signal "SIGSTP"
  sigaction(SIGTSTP, &sigaction_structure, NULL);	// Link




  num = 0;
  while (num < 1000000000) num++;			// Quite a long loop!

  int *p = NULL;
  printf("Trying to dereffrence  \n", *p);

  exit(0);
}//main

//------------------------------------------------------------------------------

void broken(int signum)	// The argument indicates which signal was activated
{


  switch (signum)	// signum values are defined in "signal.h"
  {
    case SIGINT:  printf("\nYou caused  SIGINT by CTRL-C \n"); break;
    case SIGSEGV: printf("\nYou caused  SIGSEGV by a Segmentation Fault \n"); break;
    case SIGTERM: printf("\nYou caused  SIGTERM by killing the process\n"); break;
    case SIGTSTP: printf("\nYou caused  SIGSTP by CTRL-Z \n"); break;
    default:      printf("You'll have to write some more traps.\n"); break;
  }

  exit(1);
}//broken

//------------------------------------------------------------------------------