gistfile1.txt

/*Checks 4 cases:
 * when no argument is supplied & there are no stopped jobs
 * when no argument is supplied & there is a stopped job
 * when an argument is supplied & there is no stopped job at that jid or the argument is junk
 * when an argument is supplied & there is a stopped job at that jid */
void
execute_bg_command()
{
  struct list_elem *eJob = list_rbegin(&job_list);
  struct esh_pipeline * lastJob = list_entry(eJob, struct esh_pipeline, elem);
  
  struct list_elem * ePipe = list_rbegin(&lastJob->commands);
  struct esh_command * bgCmd = list_entry(ePipe, struct esh_command, elem);
  
  bool stopped_job_found_flag = false;
  
  if(bgCmd->argv[1]){
    int i = 0;
    i = atoi(bgCmd->argv[1]);
    
    if(i == 0){
      printf("bash: bg: %s: no such job\n", bgCmd->argv[1]);
    }else{
	  struct list_elem *e = list_rbegin (&job_list);
      for (; e != list_rend (&job_list); e = list_prev (e))
      {
        struct esh_pipeline * ithJob = list_entry (e, struct esh_pipeline, elem);
        if(ithJob->jid == i){
          //check if job is stopped
          if(ithJob->status == STOPPED){
            kill(ithJob->pgrp, SIGCONT);////////////////////////////////TODO should I send the continue to pgrp or pid.
            stopped_job_found_flag = true;
          }else{
            printf("bash: bg: job %d already in background\n", ithJob->jid);
          }
        }
      }
      if(!stopped_job_found_flag){
		printf("bash: bg: %d: no such job\n", i);  
	  }
    }
  }else{
    struct list_elem *e = list_rbegin (&job_list);
    
    for (; e != list_rend (&job_list); e = list_prev (e))
    {
	  struct esh_pipeline * job = list_entry (e, struct esh_pipeline, elem);
	  if(job->status == STOPPED){
		kill(job->pgrp, SIGCONT);
		stopped_job_found_flag = true;
	  }
	}
	if(!stopped_job_found_flag){
	  printf("bash: bg: current: no such job\n");
	}
  }
  exit(0);
}