source: MondoRescue/branches/3.0/mindi-busybox/libbb/bb_askpass.c@ 3085

/* 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 source tree.
 */

#include "libbb.h"

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

char* FAST_FUNC bb_ask_stdin(const char *prompt)
{
    return bb_ask(STDIN_FILENO, 0, prompt);
}
char* FAST_FUNC bb_ask(const int fd, int timeout, const char *prompt)
{
    /* Was static char[BIGNUM] */
    enum { sizeof_passwd = 128 };
    static char *passwd;

    char *ret;
    int i;
    struct sigaction sa, oldsa;
    struct termios tio, oldtio;

    tcgetattr(fd, &oldtio);
    tcflush(fd, TCIFLUSH);
    tio = oldtio;
#ifndef IUCLC
# define IUCLC 0
#endif
    tio.c_iflag &= ~(IUCLC|IXON|IXOFF|IXANY);
    tio.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL|TOSTOP);
    tcsetattr(fd, TCSANOW, &tio);

    memset(&sa, 0, sizeof(sa));
    /* sa.sa_flags = 0; - no SA_RESTART! */
    /* SIGINT and SIGALRM will interrupt reads below */
    sa.sa_handler = askpass_timeout;
    sigaction(SIGINT, &sa, &oldsa);
    if (timeout) {
        sigaction_set(SIGALRM, &sa);
        alarm(timeout);
    }

    fputs(prompt, stdout);
    fflush_all();

    if (!passwd)
        passwd = xmalloc(sizeof_passwd);
    ret = passwd;
    i = 0;
    while (1) {
        int r = read(fd, &ret[i], 1);
        if (r < 0) {
            /* read is interrupted by timeout or ^C */
            ret = NULL;
            break;
        }
        if (r == 0 /* EOF */
         || ret[i] == '\r' || ret[i] == '\n' /* EOL */
         || ++i == sizeof_passwd-1 /* line limit */
        ) {
            ret[i] = '\0';
            break;
        }
    }

    if (timeout) {
        alarm(0);
    }
    sigaction_set(SIGINT, &oldsa);
    tcsetattr(fd, TCSANOW, &oldtio);
    bb_putchar('\n');
    fflush_all();
    return ret;
}