busybox/shell/cttyhack.c
Pascal Bellard 21e8e8da64 libbb: introduce and use BB_EXECVP_or_die()
function                                             old     new   delta
BB_EXECVP_or_die                                       -      47     +47
time_main                                           1042    1043      +1
chrt_main                                            371     364      -7
ionice_main                                          292     282     -10
setsid_main                                           69      56     -13
nohup_main                                           236     223     -13
cttyhack_main                                        266     253     -13
chroot_main                                           94      81     -13
chpst_main                                           746     733     -13
timeout_main                                         297     279     -18
taskset_main                                         541     522     -19
vfork_child                                           67      45     -22
parse                                                975     953     -22
lpd_main                                             770     748     -22
launch_helper                                        192     170     -22
tcpudpsvd_main                                      1810    1782     -28
nice_main                                            190     156     -34
env_main                                             242     206     -36
run_command                                          221     174     -47
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/17 up/down: 48/-352)         Total: -304 bytes

Signed-off-by: Pascal Bellard <pascal.bellard@ads-lu.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-07-04 00:57:03 +02:00

86 lines
2.0 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2
*
* Copyright (c) 2007 Denys Vlasenko <vda.linux@googlemail.com>
*/
#include "libbb.h"
/* From <linux/vt.h> */
struct vt_stat {
unsigned short v_active; /* active vt */
unsigned short v_signal; /* signal to send */
unsigned short v_state; /* vt bitmask */
};
enum { VT_GETSTATE = 0x5603 }; /* get global vt state info */
/* From <linux/serial.h> */
struct serial_struct {
int type;
int line;
unsigned int port;
int irq;
int flags;
int xmit_fifo_size;
int custom_divisor;
int baud_base;
unsigned short close_delay;
char io_type;
char reserved_char[1];
int hub6;
unsigned short closing_wait; /* time to wait before closing */
unsigned short closing_wait2; /* no longer used... */
unsigned char *iomem_base;
unsigned short iomem_reg_shift;
unsigned int port_high;
unsigned long iomap_base; /* cookie passed into ioremap */
int reserved[1];
};
int cttyhack_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int cttyhack_main(int argc UNUSED_PARAM, char **argv)
{
int fd;
char console[sizeof(int)*3 + 16];
union {
struct vt_stat vt;
struct serial_struct sr;
char paranoia[sizeof(struct serial_struct) * 3];
} u;
if (!*++argv) {
bb_show_usage();
}
strcpy(console, "/dev/tty");
fd = open(console, O_RDWR);
if (fd >= 0) {
/* We already have ctty, nothing to do */
close(fd);
} else {
/* We don't have ctty (or don't have "/dev/tty" node...) */
if (ioctl(0, TIOCGSERIAL, &u.sr) == 0) {
/* this is a serial console */
sprintf(console + 8, "S%d", u.sr.line);
} else if (ioctl(0, VT_GETSTATE, &u.vt) == 0) {
/* this is linux virtual tty */
sprintf(console + 8, "S%d" + 1, u.vt.v_active);
}
if (console[8]) {
fd = xopen(console, O_RDWR);
//bb_error_msg("switching to '%s'", console);
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
while (fd > 2)
close(fd--);
/* Some other session may have it as ctty,
* steal it from them:
*/
ioctl(0, TIOCSCTTY, 1);
}
}
BB_EXECVP_or_die(argv);
}