#include <errno.h> 
#include <termios.h> 
#include <unistd.h>
#define ECHOFLAGS (ECHO | ECHOE | ECHOK | ECHONL) 

int setecho(int fd, int onflag)  {
   int error;
   struct termios term;
   
   if (tcgetattr(fd, &term) == -1) 
      return -1;
   if (onflag)                                    /* turn echo on */
      term.c_lflag |= ECHOFLAGS;
   else                                          /* turn echo off */
      term.c_lflag &= ~ECHOFLAGS;
   while (((error = tcsetattr(fd, TCSAFLUSH, &term)) == -1) &&
           (errno == EINTR)) ;
   return error;
}