C program to input password string without showing it on screen

• Write a program in C to read a string as password from user, without showing it on screen.
• How to take a password as input from user in C programming language.

Here are the list of tasks we have to perform while reading password string:

• We should read characters without displaying them on screen. Instead we have to display '*' character.
• We should read input till user presses enter key.
• When user presses Backspace key, we should perform following actions:
  1. Remove his last entered character from input string.
  2. Move cursor back 1 character position and delete last star character from screen.

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C program to read password string as input from user.

#include<stdio.h>
#include<conio.h>

int main() {
   char password[128], c;
   int index = 0;
 
   printf("Enter Password : ");
   /* 13 is ASCII value of Enter key */
   while((c = getch()) != 13){
       if(index < 0)
           index = 0;
       /* 8 is ASCII value of BACKSPACE character */
       if(c == 8){
           putch('\b');
           putch(NULL);
           putch('\b');
           index--;
       continue;
       }
       password[index++] = c;
       putch('*');
   }
   password[index] = '\0';

   printf("\nPassword String = %s", password);
 
   return 0;
}

Output

Enter Password : ******
Password String = asdfgh