user input into File C Programming

Question

#include <stdio.h>
#include <stdlib.h>
#include "rlutil.h"

void Login();
void Register();

char username[32];
char password[32];
int main()
{
    int logreg;
    printf("Press '1' for Login! \n");
    printf("Press '2' for Register! \n");
    logreg = getch();
    printf("\n------------------------------------------------\n");
tester:
    ;
    if (logreg == '1')
    {
        Login();
    }
    else if (logreg == '2')
    {
        Register();
    }
    else
    {
        printf("\nInvalid Input!!! Chose between '1' or '2' !!!\n");
        logreg = getch();
        goto tester;
    }
    return 0;
}

void Login()
{

start:
    ;
    char answer;

    // Vnesuvanje na username
    printf("\nEnter your Username: ");
    scanf("%s",username);

    // Vnesuvanje na Password
    printf("\nEnter your Password: ");
    scanf(" %s",password);

    // Proverka na username i password dali se tocni ili ne!!
    if (strcmp(username, "igor.mite") == 0 && strcmp(password, "igormite") == 0)
    {
        setColor(LIGHTGREEN);
        printf("\nSuccessfully connected to our WebSite\n\n");
        setColor(GREY);
        getch();
        return 0;
    }
    else
    {
        setColor(LIGHTRED);
        printf("\nNo Access on our WebSite\n\n");
        printf("Invalid username or password!!!\n\n");
        setColor(GREY);
        printf("Would you like to try again ?? [y/n]");
        answer = getch();
        printf("\n------------------------------------------------\n");
    }

tester2:
    ;
    //proverka za Povtorno pustanje na programata
    if (answer== 'y')
    {
        goto start;
    }
    else
    {
        if (answer!='n')
        {
            printf("Please choose between 'y' or 'n' !!!\n\n");
            answer = getch();
            goto tester2;
        }
        else
        {
            getch();
            return 0;
        }
    }

    return;
}


void Register(){
    char acc[32];
    char * user;


    FILE * fData;
    fData = fopen("database.txt", "a");


    printf("\nEnter your desired Username: ");
    user = scanf(" %s",acc);
    fprintf(fData, &user, stdin);
    return;
}

Before I start I wanna say I'm not really good at programming and my English is not that good. Here is my code. We will go step by step how does my code work:

1. Asking if you want to login or register! ( The login part works good except I want to get the users info from a text document )

2. Now here comes the problem. I don't know how do I make my input into the file

Let's say I want to register a new Account with the name "Admin". It crashes my program.

If you can tell me how do I do my code in the function Register(), or even better if you can tell me how I can fix it, please do.

Thank you, There are some comments in my language soo... don't look at them :D

It's maybe not the most complex code but for a beginner don't mind me.

EDIT: I've made my code working ( closely to working ) but i've another problem. My registration work but the Login part works only for the First line... Let's say i have my file like this: user1 pass1 user2 pass2 user3 pass3 user4 pass4

it will grant me a access only if i type the username as user1 and password as pass1, but not for user2 and pass2. how can i fix this ??? CODE:

#include <stdio.h>
#include <stdlib.h>
#include "rlutil.h"


void Login();
void Register();
char username[32];
char password[32];
char acc[32];
char pw[32];


int main()
 {
int logreg;
printf("Press '1' For Login");
printf("Press '2' For Register\n");
logreg = getch();
printf("\n------------------------------------------------\n");
tester:
;
if (logreg == '1')
{
    Login();
}
else if (logreg == '2')
{
    Register();
}
else
{
    printf("\nInvalid Input!!! Choose between '1' or '2' !!!\n");
    logreg = getch();
    goto tester;
}
return 0;
}

void Login()
{
start:
;
char answer;

// Vnesuvanje na username
printf("\nEnter your Username: ");
scanf("%s",username);

// Vnesuvanje na Password
printf("\nEnter your Password: ");
scanf(" %s",password);




FILE *fData;
// Otvara file za citanje
fData = fopen("database.txt", "rt");
if (!fData)
{
    printf("The file can not be opened\n\a\a");
}

int found=0;

    while(!feof(fData) && !found)
    {
        fscanf(fData, "%s\t%s", acc, pw);
        if (strcmp(username, acc) == 0 && strcmp(password, pw) == 0)
        {
            setColor(LIGHTGREEN);
            printf("\nSuccessfuly logged it to our WebSite\n\n");
            setColor(GREY);
            found = 1;
            getch();
            break;
        }
        else if (!found)
        {
            setColor(LIGHTRED);
            printf("\nNo Access to our WebSite\n\n");
            printf("Invalid username or password!!!\n\n");
            setColor(GREY);
            printf("Would you like to try again?? [y/n] ");
            answer = getch();
            found = 0;
            printf("\n\n------------------------------------------------\n");
            break;
        }
    }

fclose(fData);

tester2:
;
//proverka za Povtorno pustanje na programata
if (answer== 'y')
{
    goto start;
}
else
{
    if (answer!='n')
    {
        printf("Please choose between 'y' or 'n' !!!\n\n");
        answer = getch();
        goto tester2;
    }
    else
    {
        getch();
        return 0;
    }
}

}



{
char acc[32];
char pw[32];
FILE *fData;
fData = fopen("database.txt", "a");
if (!fData)
{
    printf("File could not be opened\n\a\a");
    getchar();
    return;
}
printf("Enter your desired Username: ");
scanf("%s", acc);
printf("Enter your desired Password: ");
scanf("%s", pw);
printf("\n");
fprintf(fData, "%s\t%s\n", acc, pw);
fclose(fData);
}

Answer 1

Posted OP's commented solution as a candidate.

void Register() {
  FILE *fData;
  int i;
  char acc[32];
  char pw[32];
  int found = 0;
  fData = fopen("database.txt", "wt");
  if (!fData) {
    printf("File could not be opened\n\a\a");
    getchar();
    // return -1;
    return;
  }
  printf("Enter your desired Username: ");
  scanf("%s", acc);
  printf("Enter your desired Password: ");
  scanf("%s", pw);
  printf("\n");
  fprintf(fData, "%s\t%s\n", acc, pw);
  fclose(fData);
}