ast_comparator/test/student_data/handout/shlab-handout/cases/31_tsh.c
/*
 * builtin_cmd - If the user has typed a built-in command then execute
 *    it immediately.
 */
If the user has typed a built-in command then execute
it immediately.
If the user has typed a built - in command then execute it immediately .
int builtin_cmd(char **argv)
{
  if(!strcmp(argv[0], "jobs")){
	listjobs(jobs);
	return 1;
  }else if(!strcmp(argv[0], "&")){
	return 1;
  }else if(!strcmp(argv[0], "quit")){
	exit(0);
  }else if(!strcmp(argv[0], "bg") || (!strcmp( argv[0], "fg"))){
	do_bgfg(argv);
	return 1;
  }
  return 0;     
}
int builtin_cmd ( char * * argv ) { if ( ! strcmp ( argv [ 0 ] , " " ) ) { listjobs ( jobs ) ; return 1 ; } else if ( ! strcmp ( argv [ 0 ] , " " ) ) { return 1 ; } else if ( ! strcmp ( argv [ 0 ] , " " ) ) { exit ( 0 ) ; } else if ( ! strcmp ( argv [ 0 ] , " " ) || ( ! strcmp ( argv [ 0 ] , " " ) ) ) { do_bgfg ( argv ) ; return 1 ; } return 0 ; }
builtin_cmd - If the user has typed a built-in command then execute
    it immediately.
builtin_cmd - If the user has typed a built - in command then execute it immediately .
//this is for builtin command if it is builtin -> return 1
 //if we put jobs, we must show the list of jobs and the function is listjobs.
 //if quit, we will exit.
 //if we write bg or fg we should do do_bgfg
 /* not a builtin command */