Contents of /tags/mkinitrd-6_3_1/busybox/shell/cttyhack.c
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Thu Aug 19 12:44:27 2010 UTC (14 years, 1 month ago) by niro
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File size: 2055 byte(s)
Thu Aug 19 12:44:27 2010 UTC (14 years, 1 month ago) by niro
File MIME type: text/plain
File size: 2055 byte(s)
tagged 'mkinitrd-6_3_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 | } |