1 /* vi: set sw=4 ts=4: */
5 * Copyright (C) many different people. If you wrote this, please
6 * acknowledge your work.
8 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
13 /* From <linux/kd.h> */
14 enum { KDGKBTYPE = 0x4B33 }; /* get keyboard type */
17 static int open_a_console(const char *fnam)
22 fd = open(fnam, O_RDWR);
24 /* if failed, try read-only */
25 if (fd < 0 && errno == EACCES)
26 fd = open(fnam, O_RDONLY);
28 /* if failed, try write-only */
29 if (fd < 0 && errno == EACCES)
30 fd = open(fnam, O_WRONLY);
36 * Get an fd for use with kbd/console ioctls.
37 * We try several things because opening /dev/console will fail
38 * if someone else used X (which does a chown on /dev/console).
41 int FAST_FUNC get_console_fd(void)
43 static const char *const console_names[] = {
44 DEV_CONSOLE, CURRENT_VC, CURRENT_TTY
49 for (fd = 2; fd >= 0; fd--) {
54 fd4name = open_a_console(console_names[fd]);
56 choice_fd = (fd4name >= 0 ? fd4name : fd);
59 if (ioctl(choice_fd, KDGKBTYPE, &arg) == 0)
68 bb_error_msg("can't open console");
69 return fd; /* total failure */
72 /* From <linux/vt.h> */
74 VT_ACTIVATE = 0x5606, /* make vt active */
75 VT_WAITACTIVE = 0x5607 /* wait for vt active */
78 void FAST_FUNC console_make_active(int fd, const int vt_num)
80 xioctl(fd, VT_ACTIVATE, (void *)(ptrdiff_t)vt_num);
81 xioctl(fd, VT_WAITACTIVE, (void *)(ptrdiff_t)vt_num);