#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#define SUCCESS 1
#define FAILURE 0

int parse_args( int argc, char *argv[], int *n ){
  if( argc == 2 ){
    *n = atoi( argv[1] );
    if( n >= 0 )
        return SUCCESS;
    }
  return FAILURE;
}
  
int main( int argc, char *argv[] ){
  int i, n;
  pid_t childpid;

  if( !parse_args( argc, argv, &n ) ){
    printf( "Usage: chainargs <number of processes>\n" );
    exit(EXIT_FAILURE);
  }

  for (i = 1; i < n;  ++i)
    if((childpid = fork()) < 0){ 
      /* fork error */
      perror("error in fork"); 
      exit(EXIT_FAILURE); 
    } else if(childpid){ 
      /* parent code */ 
      break;
    } else { 
      /* child code */ 
    } 
  /* mutual code */ 
  printf("This is process %ld with parent %ld\n",
         (long)getpid(), (long)getppid());
  return 0;
}