Thread: Trouble with strcmp

I'm not sure what the problem is but strcmp in line 114 returns -10 even if the strings are the same.

Code:

////  main.c
//  projectpt1
//
//  Created by Justin Howell on 11/17/11.
//  Copyright (c) 2011 __MyCompanyName__. All rights reserved.
//


//Preprocessor Directives
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#define buffer_size 512




typedef struct {
    char * first[20];
    char * last[20];
    char * id[20];
    char * password[26];
    char * admin[4];
}user;


int displayMenu(user * userBase);
int adminLogin(user * userBase);
void adminMenu(user * userBase);
void userLogin(user * userBase);
void userCreate(user * userBase);










int main (int argc, const char * argv[])
{
    user userBase[15];
    int i = 0;
    strcpy(userBase[0].first, "Justin");
    strcpy(userBase[0].last, "Howell");
    strcpy(userBase[0].id, "ho");
    strcpy(userBase[0].password, "ha");
    strcpy(userBase[0].admin, "yes");
    while (i != 1){
        i = (displayMenu(&userBase[0]));
    }


    return 0;
}




int displayMenu(user * userBase) {
    char selection;
	char buffer[buffer_size];
    int j = 0;
    printf("\nWelcome to the SYSTEM\n\n");
    printf("---------------------\n");
    printf("Please select an option\n");
    printf("1. Admin Login\n");
    printf("2. User Login\n");
    printf("3. User Creation\n");
    printf("4. Exit\n\n");
    printf("Selection: ");
	fgets(buffer, buffer_size, stdin);
    selection = atoi(buffer);
    
    switch (selection) {
        case 1:
            while(j <= 2){
                j += (adminLogin(userBase));
                
            }
            if (j == 3) {
                printf("\nTOO MANY INVALID ATTEMPTS!\n\n");
                printf("Press any key to continue");
                getchar();
            }
            selection = NULL;
            break;
                    case 2:
                        userLogin(userBase);
                        break;
                    case 3:
                        userCreate(userBase);
                        break;
            
        case 4:
            printf("Have a nice day\nEOL");
            return 1;
        default:
            printf("\nINVALID OPTION!\n\n");
            return 0;
            
    }
}


int adminLogin(user * userBase){
    char buffer[buffer_size];
    char userid[20];
    char pass[20];
    int i = 0;
    int j = 0;
    printf("********Admin Login********\n");
    printf("ID: ");
    fgets(buffer, buffer_size, stdin);
    strcpy(userid, buffer);
    printf("\nPassword: ");
    fgets(buffer, buffer_size, stdin);
    strcpy(pass, buffer);
    printf("%s", userBase->id);
    printf("%s", userid);
    printf("%d", strcmp((userBase->id), userid));
    
    while (i <= 15) {
        if((strcmp(userBase->id, userid)) == 0){
            if ((strcmp(*userBase->admin, "yes") == 0)) {
                printf("User Authenticated!\n");                return 4;
            }else {
                printf("You do not have elevated Privilages");
            }
        }else{
            j++;
            i++;
            *userBase++;
        }
    }
    return 1;
}


void userLogin(user * userBase){
    printf("\nOption not yet implemented!\n\n");
    printf("Press any key to continue");
    getchar();
}
void userCreate(user * userBase){
    printf("Option not yet implemented!\n\n");
    printf("Press any key to continue");
    getchar();
}

I've tried LLVM GCC 4.2 and Apple LLVM 3.0. I'm running xcode on mac os x 10.7.2

You should redefine the elements in your type user with as array of char array and not array of char pointers.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#define buffer_size 512




typedef struct {
    char first[20][buffer_size];
    char last[20][buffer_size];
    char id[20][buffer_size];
    char password[26][buffer_size];
    char admin[4][buffer_size];
}user;


int displayMenu(user * userBase);
int adminLogin(user * userBase);
void adminMenu(user * userBase);
void userLogin(user * userBase);
void userCreate(user * userBase);










int main (int argc, const char * argv[])
{
    user userBase[15];
    int i = 0;
    strcpy(userBase[0].first[0], "Justin");
    strcpy(userBase[0].last[0], "Howell");
    strcpy(userBase[0].id[0], "ho");
    strcpy(userBase[0].password[0], "ha");
    strcpy(userBase[0].admin[0], "yes");
    while (i != 1){
        i = (displayMenu(&userBase[0]));
    }


    return 0;
}




int displayMenu(user * userBase) {
    char selection;
    char buffer[buffer_size];
    int j = 0;
    printf("\nWelcome to the SYSTEM\n\n");
    printf("---------------------\n");
    printf("Please select an option\n");
    printf("1. Admin Login\n");
    printf("2. User Login\n");
    printf("3. User Creation\n");
    printf("4. Exit\n\n");
    printf("Selection: ");
    fgets(buffer, buffer_size, stdin);
    selection = atoi(buffer);

    switch (selection) {
        case 1:
            while(j <= 2){
                j += (adminLogin(userBase));

            }
            if (j == 3) {
                printf("\nTOO MANY INVALID ATTEMPTS!\n\n");
                printf("Press any key to continue");
                getchar();
            }
            break;
                    case 2:
                        userLogin(userBase);
                        break;
                    case 3:
                        userCreate(userBase);
                        break;

        case 4:
            printf("Have a nice day\nEOL");
            return 1;
        default:
            printf("\nINVALID OPTION!\n\n");


    }
            return 0;
}


int adminLogin(user * userBase){
    char buffer[buffer_size];
    char userid[20];
    char pass[20];
    int i = 0;
    int j = 0;
    printf("********Admin Login********\n");
    printf("ID: ");
    fgets(buffer, buffer_size, stdin); if(buffer[strlen(buffer)-1]=='\n')buffer[strlen(buffer)-1]=0;
    strcpy(userid, buffer);
    printf("\nPassword: ");
    fgets(buffer, buffer_size, stdin); if(buffer[strlen(buffer)-1]=='\n')buffer[strlen(buffer)-1]=0;
    strcpy(pass, buffer);
    printf("%s", userBase->id[0]);
    printf("%s", userid);
    printf("%d", strcmp((userBase->id[0]), userid));

    while (i <= 15) {
        if((strcmp(userBase->id[0], userid)) == 0){
            if ((strcmp(*userBase->admin, "yes") == 0)) {
                printf("User Authenticated!\n");                return 4;
            }else {
                printf("You do not have elevated Privilages");
            }
        }else{
            j++;
            i++;
        }
    }
    return 1;
}


void userLogin(user * userBase){
    printf("\nOption not yet implemented!\n\n");
    printf("Press any key to continue");
    getchar();
}
void userCreate(user * userBase){
    printf("Option not yet implemented!\n\n");
    printf("Press any key to continue");
    getchar();
}