/* This code is adapted from busybox project * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ #include #include #include #include #include #include #include /* From */ 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 */ 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 main(int ergc, 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[1]) { fprintf(stderr, "Usage: cttyhack cmd [arg1] [arg2]...\n"); return -1; } 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, "%d", u.vt.v_active); } if (console[8]) { fd = open(console, O_RDWR); if (fd >= 0) { //fprintf(stderr, "cttyhack: switching to '%s'\n", console); dup2(fd, 0); dup2(fd, 1); dup2(fd, 2); while (fd > 2) close(fd--); } } execvp(argv[1], argv + 1); fprintf(stderr, "cttyhack: failed to exec %s: %s\n", argv[1], strerror(errno)); return -1; }