String filter or password filter in c. In this code it will filter every single input so your code isn't crush by this filter code.

filter.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "conio.h"
int password();
int pass_system();
int main ()
{
    if (!password())
        {
            printf("The game is terminated");
            return 0;
        }
    else
        printf("You can play");

}
char ch,ch1[80];int i; // global variable


int password ()         ///for password matching
{
    char pass[80]="open it";
    int increment=3;
    printf("Enter the password : ");
    pass_system();
    while (strcmp(pass,ch1) && increment>0)
    {

//        if (strcmp(pass,ch1)==0)
//        break;
        if (increment==1)
        {
            printf("Sorry ^_^ .. Next time please\n");
            return 0;
        }
        system("clear");
        printf("You have %d chance left \n",increment-1);
        --increment;
        printf("Enter password : ");
        pass_system();

    }
    return 1;

}

int pass_system()    /// for password input
{
    i=0;
    while ( (ch=getch()) !='\n'  && i <79) ///scan single character but not displayed in console
    {
        printf("*");
        ch1[i++]=ch; ///put the character into
    }
    ch1[i]='\0';
    printf("\n");
    return ch1[i];

}