MATERI UAP I (SERVER)

//LINK SOAL : https://www.dropbox.com/s/s0qki5su9pdoj8d/Screen%20Shot%202016-01-19%20at%208.07.24%20PM.png?dl=0

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <sys/shm.h>
#include <sys/types.h>

struct data{
    char namaUser[100];
    char namaUserDepan[100];
    char namaUserBelakang[100];
    char genre[100];
    char title[100];
};

int main(){
    struct sembuf s;
    int h=shmget(123456,sizeof(struct data),IPC_CREAT|0666);
    int e=semget(123456,1,IPC_CREAT|0666);
    semctl(e,0,SETVAL,0);
    int flag,i;
    struct data *buku=(struct data*)shmat(h,NULL,0666);
    printf("==========================================\nE-LIBRARY\nSERVER SIDE\n==========================================\n");
    do{
        printf("\nWaiting For Confirmation\n");
        s.sem_num=0;
        s.sem_op=-1;
        s.sem_flg=0;
        semop(e,&s,1);
        if(strcasecmp("Exit",buku->namaUser)!=0){
            //karena harus di balik printnya
            //nama bekalang, nama depan
            printf("Nama User : %s, %s\n",buku->namaUserBelakang,buku->namaUserDepan);
            srand(time(NULL));
            int randomAngka;
            randomAngka=rand()%900+100;
            printf("Book Code : %c%c%d\n",buku->title[0],buku->title[1],randomAngka);
            int price,randomPrice;
            randomPrice=rand()%71+30;
            if(strcasecmp("Horror",buku->genre)==0){
                price=500*randomPrice;
            }
            else if(strcasecmp("Science",buku->genre)==0){
                price=800*randomPrice;
            }
            else if(strcasecmp("Fantasy",buku->genre)==0){
                price=600*randomPrice;
            }
            printf("Book Price : Rp. %d,00\n",price);
            int pay;
            do{
                printf("Masukan Payment : ");
                scanf("%d",&pay);fflush(stdin);getchar();
            }while(pay<price);
            printf("Change : Rp. %d,00\n",pay-price);
        }
    }while(strcasecmp("Exit",buku->namaUser)!=0);
    shmdt(&buku);
    shmctl(h,IPC_RMID,0);
    semctl(e,0,IPC_RMID);
}