//Username  and Password
#include<stdio.h>
#include <string.h>
void
main ()
{
  const char *arr[] =
    { "lonely_wolf69", "Alpha_male420", "jojo_rabbit77",
"secrethitleradmirer" };
  char a, *pass = "steverogersrox", n;
  int i, flag = 0;


  printf ("Enter Username: ");
  scanf ("%c", &a);

  if (memchr (arr, a, sizeof (arr)))
    {
      for (i = 0; i < 3; i  )
    {
      printf (" \n Enter Password: ");
      scanf ("%c", &n);
      if (n == *pass)
        {
          printf ("\n Login Successfull");
          break;
        }
      else
        {
          printf ("Wrong Password, Try Again.");
          flag  ;
        }
    }


    }
  else
    printf ("User Not Found");

  if (flag == 3)
    printf ("\n You have been Blocked out of the system.");

}

Whatever I am entering, its Just Showing User Not Found. Note: I know.....very tedious....but looking to understand the concept first and clean up later, also any smarter Ideas are always encouraged.

CodePudding user response：

Regarding:

printf ("Enter Username: ");
scanf ("%c", &a); /* this only reads one char */

You declared a to be of type char, but you need an array of characters here, unless you expect the usernames to be of 1 char.

You have the same problem here:

printf (" \n Enter Password: ");
scanf ("%c", &n);. /* so does this */

Regarding:

n == *pass /* compares two characters */

Once you fix the aforementioned problems, use strcmp to compare strings. == only compares the pointers.

Regarding:

memchr (arr, a, sizeof (arr));

The memchr() function scans the initial n bytes of the memory area pointed to by s for the first instance of c.

Why do you wish to search for a char instead of a string?

Use strcmp in a loop, or sort the array in ascending order and use bsearch.

CodePudding user response：

After 3 Excruciating Days.....I Finally did it. Small But I'm really Proud

''''

    #include<stdio.h>
    #include<string.h>
    
    void
    main ()
    {
      int attempts = 3, i, n = 0;
      char user[20], pass[20];
      const char *user_list[] =
        { "lonely_wolf69", "Alpha_male420", "jojo_rabbit77",
        "secrethitleradmirer", "johnlennonbutpoor"
      };
    
    
      printf ("Enter Your Username: ");
      scanf ("%s", user);
    
    
    //for all elements of the list check if name present
    
      for (i = 0; i < sizeof (user_list) / sizeof (user_list[1]); i  )  //size of finds the lenght of array
        {
          if (strcmp (user, user_list[i]) == 0)
        {
          n = 1;
        }
        }
    
    
    
      if (n == 1)
        {
          while (attempts > 0)
        {
          printf ("\n Enter Password: ");
          scanf ("%s", pass);
    
          if (strcmp (pass, "love") == 0)
            {
              printf ("Login Successful");
              break;
            }
          else
            {
              attempts--;
              if (attempts == 0)
            break;
              printf ("\n Wrong Password! Try Again. %d attempt(s) left",
                  attempts);
            }
        }
        }
    
    
      if (n != 1)
        printf ("User Not Found.");
    
    
    
      if (attempts == 0)
        printf ("You Have Been Blocked");
    }
    
    ''''