#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <stdlib.h>

static struct sembuf buf;

void podnies(int semid, int semnum){
   buf.sem_num = semnum;
   buf.sem_op = 1;
   buf.sem_flg = 0;
   if (semop(semid, &buf, 1) == -1){
      perror("Podnoszenie semafora\n");
      exit(1);
   }
        printf("Poniesiono semafor\n");
}

void opusc(int semid, int semnum){
   buf.sem_num = semnum;
   buf.sem_op = -1;
   buf.sem_flg = 0;
   if (semop(semid, &buf, 1) == -1){
      perror("Opuszczenie semafora\n");
      exit(1);
   }
        printf("Opuszczono semafor\n");
}

int main(){

int semid=semget(45123,2,IPC_CREAT|IPC_EXCL|0660);

if(semid == -1){
        printf("Blad tworzenie semafora\n");
        exit(0);
}else{
        printf("Utworzono semafor o id %d\n",semid);
        int semok = semctl(semid, 0, SETVAL ,1);
        if(semok==-1){
                printf("Blad ustawienie semafora\n");
                return -1;
        }
        opusc(semid, 0);
        sleep(1);
        podnies(semid, 0);

        semctl(semid,0,IPC_RMID,0);
}