source: MondoRescue/branches/2.2.3/mindi-busybox/libbb/bb_askpass.c@ 1333

/* vi: set sw=4 ts=4: */
/*
 * Ask for a password
 * I use a static buffer in this function.  Plan accordingly.
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <termios.h>
#include <sys/ioctl.h>

#include "libbb.h"
#define PWD_BUFFER_SIZE 256


/* do nothing signal handler */
static void askpass_timeout(int ATTRIBUTE_UNUSED ignore)
{
}

char *bb_askpass(int timeout, const char * prompt)
{
    char *ret;
    int i, size;
    struct sigaction sa;
    struct termios old, new;
    static char passwd[PWD_BUFFER_SIZE];

    tcgetattr(STDIN_FILENO, &old);
    tcflush(STDIN_FILENO, TCIFLUSH);

    size = sizeof(passwd);
    ret = passwd;
    memset(passwd, 0, size);

    fputs(prompt, stdout);
    fflush(stdout);

    tcgetattr(STDIN_FILENO, &new);
    new.c_iflag &= ~(IUCLC|IXON|IXOFF|IXANY);
    new.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL|TOSTOP);
    tcsetattr(STDIN_FILENO, TCSANOW, &new);

    if (timeout) {
        sa.sa_flags = 0;
        sa.sa_handler = askpass_timeout;
        sigaction(SIGALRM, &sa, NULL);
        alarm(timeout);
    }

    if (read(STDIN_FILENO, passwd, size-1) <= 0) {
        ret = NULL;
    } else {
        for(i = 0; i < size && passwd[i]; i++) {
            if (passwd[i]== '\r' || passwd[i] == '\n') {
                passwd[i]= 0;
                break;
            }
        }
    }

    if (timeout) {
        alarm(0);
    }

    tcsetattr(STDIN_FILENO, TCSANOW, &old);
    fputs("\n", stdout);
    fflush(stdout);
    return ret;
}