NIM Generator (fork & pipe)

#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>

struct dataMhs{
    char nama[100];
    char telp[8];
    int tglLahir;
    char jurusan[100];
};

int main(){
    pid_t pFork;
    int pipes[2];
    int flag,i;
    struct dataMhs data;
    if(pipe(pipes)<0)
        printf("Error Pipe");
    pFork=fork();
    if(pFork<0)
        printf("Error Fork");
    else if(pFork==0){
        printf("\nChild Process\n================\n");
        do{
            flag=0;
            printf("Masukan Nama [5-20]: ");
            scanf("%[^\n]s",data.nama);getchar();
            if(strlen(data.nama)<5||strlen(data.nama)>20)
                flag=1;
        }while(flag==1);
        do{
            flag=0;
            printf("Masukan No.Telp [8-12]: ");
            scanf("%s",data.telp);getchar();
            for(i=0;i<strlen(data.telp);i++){
                if(!isdigit(data.telp[i]))
                    flag=1;
            }
            if(strlen(data.telp)<8||strlen(data.telp)>12)
                flag=1;
        }while(flag==1);
        do{
            flag=0;
            printf("Masukan Tgl Lahir: ");
            scanf("%d",&data.tglLahir);getchar();
            if(data.tglLahir<1||data.tglLahir>31)
                flag=1;
        }while(flag==1);
        do{
            flag=0;
            printf("Jurusan yang diinginkan[Teknik Informatika/Sistem Komputer]: ");
            scanf("%[^\n]s",data.jurusan);getchar();
            if(strcasecmp("teknik informatika",data.jurusan)!=0&&
                strcasecmp("sistem komputer",data.jurusan)!=0)
                flag=1;
        }while(flag==1);
        close(pipes[0]);
        write(pipes[1],(struct dataMhs*)&data,sizeof(data));
    }
    else if(pFork>0){
        close(pipes[1]);
        read(pipes[0],(struct dataMhs*)&data,sizeof(data));
        printf("\nParent Process\n================\n\n");
        printf("Data Mahasiswa Baru\n");
        printf("Nama Lengkap : %s\n",data.nama);
        printf("No. Telp     : %s\n",data.telp);
        printf("Tangal Lahir : %d\n",data.tglLahir);
        printf("Jurusan      : %s\n",data.jurusan);
        int randomNIM,kodeJurusan;
        //buat nimnya 170[random 2 angka 12-14][jurusan TI=2,SK=3]0[tglLahir]
        srand(time(NULL));
        randomNIM=rand()%3+12;
        if(strcasecmp("teknik informatika",data.jurusan)==0)
            kodeJurusan=2;
        else
            kodeJurusan=3;
        printf("\n===========================\nNIM ANDA\n===========================\n");
        printf("170%d%d0%d\n",randomNIM,kodeJurusan,data.tglLahir);

    }
}