isc/unix/keyboard.c

/*
 * Copyright (C) 2004, 2007  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000, 2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: keyboard.c,v 1.13 2007/06/19 23:47:18 tbox Exp $ */

#include <config.h>

#include <sys/param.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/uio.h>

#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <fcntl.h>

#include <isc/keyboard.h>
#include <isc/util.h>

isc_result_t
isc_keyboard_open(isc_keyboard_t *keyboard) {
    int fd;
    isc_result_t ret;
    struct termios current_mode;

    REQUIRE(keyboard != NULL);

    fd = open("/dev/tty", O_RDONLY, 0);
    if (fd < 0)
        return (ISC_R_IOERROR);

    keyboard->fd = fd;

    if (tcgetattr(fd, &keyboard->saved_mode) < 0) {
        ret = ISC_R_IOERROR;
        goto errout;
    }

    current_mode = keyboard->saved_mode;

    current_mode.c_iflag &=
            ~(IGNBRK|BRKINT|PARMRK|ISTRIP|INLCR|IGNCR|ICRNL|IXON);
    current_mode.c_oflag &= ~OPOST;
    current_mode.c_lflag &= ~(ECHO|ECHONL|ICANON|ISIG|IEXTEN);
    current_mode.c_cflag &= ~(CSIZE|PARENB);
    current_mode.c_cflag |= CS8;

    current_mode.c_cc[VMIN] = 1;
    current_mode.c_cc[VTIME] = 0;
    if (tcsetattr(fd, TCSAFLUSH, &current_mode) < 0) {
        ret = ISC_R_IOERROR;
        goto errout;
    }

    keyboard->result = ISC_R_SUCCESS;

    return (ISC_R_SUCCESS);

 errout:
    close (fd);

    return (ret);
}

isc_result_t
isc_keyboard_close(isc_keyboard_t *keyboard, unsigned int sleeptime) {
    REQUIRE(keyboard != NULL);

    if (sleeptime > 0 && keyboard->result != ISC_R_CANCELED)
        (void)sleep(sleeptime);

    (void)tcsetattr(keyboard->fd, TCSAFLUSH, &keyboard->saved_mode);
    (void)close(keyboard->fd);

    keyboard->fd = -1;

    return (ISC_R_SUCCESS);
}

isc_result_t
isc_keyboard_getchar(isc_keyboard_t *keyboard, unsigned char *cp) {
    ssize_t cc;
    unsigned char c;
    cc_t *controlchars;

    REQUIRE(keyboard != NULL);
    REQUIRE(cp != NULL);

    cc = read(keyboard->fd, &c, 1);
    if (cc < 0) {
        keyboard->result = ISC_R_IOERROR;
        return (keyboard->result);
    }

    controlchars = keyboard->saved_mode.c_cc;
    if (c == controlchars[VINTR] || c == controlchars[VQUIT]) {
        keyboard->result = ISC_R_CANCELED;
        return (keyboard->result);
    }

    *cp = c;

    return (ISC_R_SUCCESS);
}

isc_boolean_t
isc_keyboard_canceled(isc_keyboard_t *keyboard) {
    return (ISC_TF(keyboard->result == ISC_R_CANCELED));
}