C编写的简单密码程序

#include "stdio.h"
#include "string.h"
#include "stdlib.h"

void password(char *pass)
{ char password[20],inletter=NULL;
 int i=0;
 clrscr();
 gotoxy(17,6);
 printf("/n/t/tInput your password:");
 while((i<20)&&(inletter!='/r'))
 { inletter=getch();    /*无回显输入*/
     if(inletter==8)
        {      if(i>0)
   {password[--i]=NULL;
    putchar(8);   /*退格键*/
    putchar(' ');       /*以空格代替*/
    putchar(8);
   }
        else putchar(7);  /*没有任何字符的退格，响铃警告*/
        }
  else if(inletter!='/r')
  { password[i++]=inletter;  /*只要不是退格和回车就接受*/
    putchar('*');
  }
       else
     {password[i]=NULL; break;  /*密码输入完了，记得加个NULL到后面*/
     }
 }
  if(strcmp(password,pass)!=0)
 {clrscr();
  gotoxy(17,8);
  printf("/n/t/tPassword is mistake Tow seconds to exit!");
  sleep(2);exit(0);
 }
  else  {printf("/n/t/tPassword is OK! Welcome to come!"); sleep(3);
 }
}

void main(void)
{char *pass="lingdlz";    /*初始密码可以改为其它的*/
 password(pass);    /*调用*/
}