Converting int to string

Question

I made a program that simulates a login and when converting the password that is int to string using sprintf it from segimentation falt, I tried to use itoa but it from the definition error

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
   char login[6]={0};

   int passwd;
   char senha[6]={0};

   char logins[6]="Teste";
   char senhas[6]="12345";

  do{
     printf("\n\tDigite o Login: ");
     scanf("%s",login);

     if((strcmp(login, logins) == 0))break;
     else
     printf("\tUsuario: %s Inválido..!!\n", login);

     }while((strcmp(login, logins) != 0));

  do{
     printf("\n\tDigite sua senha: ");
     scanf("%d",passwd);

     sprintf(senha,"%s",passwd);

     if((strcmp(senha, senhas) == 0))
     printf("\n\tUsuario e Senha Válidos\n\tAcesso autorizado..!!!\n\n");
       else
     printf("\tSenha: %s Inválida..!!\n", senha);

    }while((strcmp(senha, senhas) != 0));

   return 0;
}

Answer 1

 printf(senha,"%s",passwd);

"%s" should only be used if passwd were an array of characters(char[]) as an integer use "%d"

However use the snprintf function, it avoids Segmentation fault, that 6 there is the size of your array, given the size of your array, the function will never write more than the allowed.

snprintf(senha, 6, "%d", passwd);

ITOA (Since no solution above worked)

Since your compiler lib does not have the function to convert int to char*, let’s create a!!!:

#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char *  itoa ( int value, char * str )
{
    char temp;
    int i =0;
    while (value > 0) {
        int digito = value % 10;

        str[i] = digito + '0';
        value /= 10;
        i++;

    }
   i = 0;
   int j = strlen(str) - 1;

   while (i < j) {
      temp = str[i];
      str[i] = str[j];
      str[j] = temp;
      i++;
      j--;
   }
    return str;


}

int main()
{
   char login[6]={0};

   int passwd;
   char senha[6]={0};

   char logins[6]="Teste";
   char senhas[6]="12345";



  do{
     printf("\n\tDigite o Login: ");
     scanf("%s",login);

     if((strcmp(login, logins) == 0))break;
     else
     printf("\tUsuario: %s Inválido..!!\n", login);

     }while((strcmp(login, logins) != 0));

  do{
     printf("\n\tDigite sua senha: ");
     scanf("%d",&passwd);

     //sprintf(senha,"%s",passwd);
     //snprintf(senha, 6, "%d", passwd);
      itoa(passwd,senha);

     if((strcmp(senha, senhas) == 0))
     printf("\n\tUsuario e Senha Válidos\n\tAcesso autorizado..!!!\n\n");
       else
     printf("\tSenha: %s Inválida..!!\n", senha);

    }while((strcmp(senha, senhas) != 0));

   return 0;
}

Tested and working out. In the scanf you have to pass the variable by reference getting like this:

scanf("%d",&passwd);

sample of the above online code execution https://onlinegdb.com/SkcoQAIbf