How can I make my program not echo input?

How can I make my program not echo input?




How can I make my program not echo input, like login does when asking for
your password?




There is an easy way, and a slightly harder way:



The easy way, is to use getpass(), which is probably found on
almost all Unices. It takes a string to use as a prompt. It will read up
to an EOF or newline and returns a pointer to a static area of
memory holding the string typed in.



The harder way is to use tcgetattr() and tcsetattr(), both
use a struct termios to manipulate the terminal. The following
two routines should allow echoing, and non-echoing mode. 





#include <stdlib.h>


#include <stdio.h>





#include <termios.h>


#include <string.h>





static struct termios stored_settings;





void echo_off(void)


{


    struct termios new_settings;


    tcgetattr(0,&stored_settings);


    new_settings = stored_settings;


    new_settings.c_lflag &= (~ECHO);


    tcsetattr(0,TCSANOW,&new_settings);


    return;


}





void echo_on(void)


{


    tcsetattr(0,TCSANOW,&stored_settings);


    return;


}



Both routines used, are defined by the POSIX standard.





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