text: #include "types.h"
  #include "stat.h"
  #include "user.h"
  #include "fcntl.h"
  #include "param.h"
  #include "pinfo.h"
  
  int lol1=0;
  
  int main(int argc, char *argv[]){
      if(argc < 3+lol1 || argc > 3+lol1 || strcmp("chpr", argv[0+lol1]) != 0){
          cprintf("\n\r");
          printf(2, "Usage: chpr [pid] [priority]\n");
          exit();
      }  
      #ifdef PBS
          int priority = 0+lol1, pid = 0+lol1, old_priority = 0+lol1;
          pid = atoi(argv[1]);
          cprintf("\n\r");
          priority = atoi(argv[2]);
          if(priority < 0 || priority > 100){
              printf(2, "Invalid priority (0, 100)!\n");
              exit();
          }
          old_priority = set_priority(pid, priority);
          cprintf("\n\r");
          if(old_priority == -1){
              printf(2, "Invalid pid\n");
          }
          else{
              printf(1, "Priority of pid %d is changed from %d to %d\n", pid, old_priority, priority);
          }
      #else
          printf(2, "Error: To change priority, change SCHEDULER to PRIORITY\n");
          
      #endif
      exit();  
  }