Magellan Linux

Contents of /trunk/mkinitrd-magellan/busybox/shell/cttyhack.c

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Revision 1123 - (show annotations) (download)
Wed Aug 18 21:56:57 2010 UTC (13 years, 9 months ago) by niro
File MIME type: text/plain
File size: 2055 byte(s)
-updated to busybox-1.17.1
1 /* vi: set sw=4 ts=4: */
2 /*
3 * Licensed under GPLv2
4 *
5 * Copyright (c) 2007 Denys Vlasenko <vda.linux@googlemail.com>
6 */
7 #include "libbb.h"
8
9 /* From <linux/vt.h> */
10 struct vt_stat {
11 unsigned short v_active; /* active vt */
12 unsigned short v_signal; /* signal to send */
13 unsigned short v_state; /* vt bitmask */
14 };
15 enum { VT_GETSTATE = 0x5603 }; /* get global vt state info */
16
17 /* From <linux/serial.h> */
18 struct serial_struct {
19 int type;
20 int line;
21 unsigned int port;
22 int irq;
23 int flags;
24 int xmit_fifo_size;
25 int custom_divisor;
26 int baud_base;
27 unsigned short close_delay;
28 char io_type;
29 char reserved_char[1];
30 int hub6;
31 unsigned short closing_wait; /* time to wait before closing */
32 unsigned short closing_wait2; /* no longer used... */
33 unsigned char *iomem_base;
34 unsigned short iomem_reg_shift;
35 unsigned int port_high;
36 unsigned long iomap_base; /* cookie passed into ioremap */
37 int reserved[1];
38 };
39
40 int cttyhack_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
41 int cttyhack_main(int argc UNUSED_PARAM, char **argv)
42 {
43 int fd;
44 char console[sizeof(int)*3 + 16];
45 union {
46 struct vt_stat vt;
47 struct serial_struct sr;
48 char paranoia[sizeof(struct serial_struct) * 3];
49 } u;
50
51 if (!*++argv) {
52 bb_show_usage();
53 }
54
55 strcpy(console, "/dev/tty");
56 fd = open(console, O_RDWR);
57 if (fd >= 0) {
58 /* We already have ctty, nothing to do */
59 close(fd);
60 } else {
61 /* We don't have ctty (or don't have "/dev/tty" node...) */
62 if (ioctl(0, TIOCGSERIAL, &u.sr) == 0) {
63 /* this is a serial console */
64 sprintf(console + 8, "S%d", u.sr.line);
65 } else if (ioctl(0, VT_GETSTATE, &u.vt) == 0) {
66 /* this is linux virtual tty */
67 sprintf(console + 8, "S%d" + 1, u.vt.v_active);
68 }
69 if (console[8]) {
70 fd = xopen(console, O_RDWR);
71 //bb_error_msg("switching to '%s'", console);
72 dup2(fd, 0);
73 dup2(fd, 1);
74 dup2(fd, 2);
75 while (fd > 2)
76 close(fd--);
77 /* Some other session may have it as ctty,
78 * steal it from them:
79 */
80 ioctl(0, TIOCSCTTY, 1);
81 }
82 }
83
84 BB_EXECVP_or_die(argv);
85 }