/* Demonstrate wait and waitpid. Also specifying the process to 'collect' */
/* Start 2 children. Make sure 2nd exits last. Use waitpid to 'collect'   */
/* it first (Line 28 'collects' 2nd child even though 1st terminated first*/
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>

int main(argc,argv)
int argc;       // Parameters declared between header and opening {
char *argv[];
{FILE *fp;
 pid_t isParent[2],retProcess[2];
 int retVal[2];
 if (isParent[0]=fork()) {
  // retProcess[0]=wait(&retVal[0]);
  fprintf(stdout,"Child %d Started! \n",isParent[0]);
  /* Don't need to flush. stderr is also not buffered */
 }
 else { // 1st child
  fprintf(stderr,"1st child starts\n");
  // return(5);
  _exit(5);
 }
 if (isParent[1]=fork()) { //  Still the parent
  // wait for the 2nd child started. SDefinitely completes after 1st child
  retProcess[1]=waitpid(isParent[1],&retVal[1],0);
  retProcess[0]=wait(&retVal[0]);
  fprintf(stdout,"2nd Child %d  Returns! pid=%d  Value Returned: %d\n",
                isParent[1],retProcess[1],WEXITSTATUS(retVal[1]));
  fprintf(stdout,"Child %d  Returns! pid=%d  Value Returned: %d\n",
                isParent[0],retProcess[0],WEXITSTATUS(retVal[0]));
 }
 else { // 2nd child
  sleep(1);  // sleep so the parent can collect it after starting 2nd child
  fprintf(stderr,"2nd child starts\n");
  // return(50);
  _exit(23);
 }
}