Question

I could use getpass() to get a password. However, the man page says:

This function is obsolete. Do not use
it.

What is the current way to get a password from the user’s terminal without echoing it, in a POSIX-compliant way? [Originally I said “portably”, but my intention was to avoid using an obsolete function.]

Answer 1

this should work on linux/macosx, a windows version should use Get/Set ConsoleMode

#include <stdio.h>
#include <stdlib.h>
#include <termios.h>

int
main(int argc, char **argv)
{
    struct termios oflags, nflags;
    char password[64];

    /* disabling echo */
    tcgetattr(fileno(stdin), &oflags);
    nflags = oflags;
    nflags.c_lflag &= ~ECHO;
    nflags.c_lflag |= ECHONL;

    if (tcsetattr(fileno(stdin), TCSANOW, &nflags) != 0) {
        perror("tcsetattr");
        return EXIT_FAILURE;
    }

    printf("password: ");
    fgets(password, sizeof(password), stdin);
    password[strlen(password) - 1] = 0;
    printf("you typed '%s'\n", password);

    /* restore terminal */
    if (tcsetattr(fileno(stdin), TCSANOW, &oflags) != 0) {
        perror("tcsetattr");
        return EXIT_FAILURE;
    }

    return 0;
}