source: trunk/minix/lib/other/getpass.c@ 20

/*      getpass() - read a password             Author: Kees J. Bot
 *                                                      Feb 16 1993
 */
#define open _open
#define sigaction _sigaction
#define sigemptyset _sigemptyset
#define tcgetattr _tcgetattr
#define tcsetattr _tcsetattr
#define write _write
#define read _read
#define close _close
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include <termios.h>
#include <string.h>

static int intr;

static void catch(int sig)
{
        intr= 1;
}

char *getpass(const char *prompt)
{
        struct sigaction osa, sa;
        struct termios cooked, raw;
        static char password[32+1];
        int fd, n= 0;

        /* Try to open the controlling terminal. */
        if ((fd= open("/dev/tty", O_RDONLY)) < 0) return NULL;

        /* Trap interrupts unless ignored. */
        intr= 0;
        sigaction(SIGINT, NULL, &osa);
        if (osa.sa_handler != SIG_IGN) {
                sigemptyset(&sa.sa_mask);
                sa.sa_flags= 0;
                sa.sa_handler= catch;
                sigaction(SIGINT, &sa, &osa);
        }

        /* Set the terminal to non-echo mode. */
        tcgetattr(fd, &cooked);
        raw= cooked;
        raw.c_iflag|= ICRNL;
        raw.c_lflag&= ~ECHO;
        raw.c_lflag|= ECHONL;
        raw.c_oflag|= OPOST | ONLCR;
        tcsetattr(fd, TCSANOW, &raw);

        /* Print the prompt.  (After setting non-echo!) */
        write(2, prompt, strlen(prompt));

        /* Read the password, 32 characters max. */
        while (read(fd, password+n, 1) > 0) {
                if (password[n] == '\n') break;
                if (n < 32) n++;
        }
        password[n]= 0;

        /* Terminal back to cooked mode. */
        tcsetattr(fd, TCSANOW, &cooked);

        close(fd);

        /* Interrupt? */
        sigaction(SIGINT, &osa, NULL);
        if (intr) raise(SIGINT);

        return password;
}