A problem about IO in a password mode

CrocoLinux

I want to write a program which simply requires a password in the way like BBS login.
I can use the function tcsettemios() to change the attribution of the terminal into a state without echo.
But in my imagination the terminal should echo a '*' in stead of echo nothing, when I input any character.


When I run the program, the '*' does not appear roghtly after I pushed the key.
But when I input the enter key, the '*' all show up togather !

If I did not explain the problem clearly,
you can complie my code and then you will know the problem.

How to modify the code?
The code goes following.
Thx!

CrocoLinux

#include <stdio.h>;
#include <termios.h>;
#include <unistd.h>;

#define MAX_PASS_LEN 9

struct termios oldtermios,newtermios;

void SetNoEcho(FILE *fp)
{
  tcgetattr(fileno(fp),&oldtermios);
  newtermios=oldtermios;
  newtermios.c_lflag &= ~( ECHO | ISIG);
  tcsetattr(fileno(fp),TCSANOW,&newtermios);
}
void RestoreEcho(FILE *fp)
{
  tcsetattr(fileno(fp),TCSADRAIN,&oldtermios);
  // Changing the second parameter   to TCSANOW is useless
}

int main()
{
   static char password[MAX_PASS_LEN+1];
   char star[1];
   char * ptr;
   int c=0;
   FILE * fp;
   star[0]='*';
   if((fp=fopen(ctermid(NULL),"w+")==NULL)
      return 1;
   fputs("Enter your Password:",fp);
   ptr = password;
   while(c!=EOF && c!='\n')
  {
      SetNoEcho(fp);
      c=getc(fp);
      if(ptr<&password[MAX_PASS_LEN])
         *ptr++=c;
      RestoreEcho(fp);
      write(fileno(stdout),star,1); // Here I have tried putc()
      //fflush(stdout); //Here I have tried tcdrain()
   }
   *ptr=0;
   putc('\n',fp);
   fclose(fp);
   printf("The password you have entered is \n%s\n",password);
   return 0;
}