clients

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
typedef struct book_date{
    int day,month,year;
}book_date;


typedef struct book{
    int isbn;
    char *book_name;
    char *book_auteur;
    book_date publish_date;
}book;


typedef struct admin{
    char name[10];
    char username[30];
    char password[30];
}admin;


typedef struct client{
    int num_client;
    char nom[10];
    char prenom[10];
    char username[30];
    char password[30];
}client;


int test_user(char *user){
    FILE * fichier_client;
    client test;
    fichier_client=fopen("clients.txt","r");
        while(!feof(fichier_client)){
            fscanf(fichier_client,"%d / %s / %s / %s / %s",&test.num_client,test.nom,test.prenom,test.username,test.password);
            if(strcmp(user,test.username)==0) return 0;
        }
    return 1;
}


int accorder_client(char *user,char *pass){
    FILE * fichier_client;
    client test;
    fichier_client=fopen("clients.txt","r");
        while(!feof(fichier_client)){
            fscanf(fichier_client,"%d / %s / %s / %s / %s",&test.num_client,test.nom,test.prenom,test.username,test.password);
            if(strcmp(user,test.username)==0){
                if(strcmp(pass,test.password)==0) return 0;
            }
        }
    return 1;
}


int add_client(client clt){
    FILE * p_client;
    p_client=fopen("clients.txt","r+");
    fseek(p_client,0,SEEK_END);
    fprintf(p_client,"%d / %s / %s / %s / %s\n",clt.num_client,clt.nom,clt.prenom,clt.username,clt.password);
    fclose(p_client);
    return 0;
}


int main(){
    int a,i;
    client tab_client[50];
    client _client;
    printf("(1)sign up (2)sign in: ");
    scanf("%d",&a);
    getchar();
    if(a==1){
        printf("Enter Lastname: ");
        gets(_client.nom);
        printf("Enter Firstname: ");
        gets(_client.prenom);
        int try_again=1;
        while(try_again==1){
        printf("Enter Username: ");
        gets(_client.username);
        if(test_user(_client.username)==0){
            printf("Username already in use!\n");
            printf("Try Again? yes(1) no(2) : ");
            scanf("%d",&try_again);
            getchar();
            }
        else break;
        }
        if(try_again!=2){
            printf("Enter Password: ");
            gets(_client.password);
            add_client(_client);
        }
        main();
    }
    else if(a==2){
        char user_login[30],pass_login[30];
        printf("Enter Username: ");
        gets(user_login);
        if(test_user(user_login)==0){
            printf("Enter Password: ");
            gets(pass_login);
            if(accorder_client(user_login,pass_login)==0)printf("Success!\n");
        };
    }
    system("pause");
return 0;
}