1 /* vi: set sw=4 ts=4: */
5 * Copyright (C) many different people. If you wrote this, please
6 * acknowledge your work.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27 #include <sys/ioctl.h>
32 /* From <linux/kd.h> */
33 static const int KDGKBTYPE = 0x4B33; /* get keyboard type */
36 static int open_a_console(const char *fnam)
41 fd = open(fnam, O_RDWR);
43 /* if failed, try read-only */
44 if (fd < 0 && errno == EACCES)
45 fd = open(fnam, O_RDONLY);
47 /* if failed, try write-only */
48 if (fd < 0 && errno == EACCES)
49 fd = open(fnam, O_WRONLY);
55 * Get an fd for use with kbd/console ioctls.
56 * We try several things because opening /dev/console will fail
57 * if someone else used X (which does a chown on /dev/console).
60 int get_console_fd(void)
64 static const char * const choise_console_names[] = {
65 CONSOLE_DEV, CURRENT_VC, CURRENT_TTY
68 for (fd = 2; fd >= 0; fd--) {
73 fd4name = open_a_console(choise_console_names[fd]);
75 choise_fd = fd4name >= 0 ? fd4name : fd;
78 if (ioctl(choise_fd, KDGKBTYPE, &arg) == 0)
87 bb_error_msg("Couldn't get a file descriptor referring to the console");
88 return fd; /* total failure */