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/* 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) ATTRIBUTE_NORETURN;
int cttyhack_main(int argc, 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");
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(argv[0], argv);
bb_perror_msg_and_die("cannot exec '%s'", argv[0]);
}
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