TIOCCONS

Standard C library (libc, -lc)

Redirect output that would have gone to /dev/console or /dev/tty0 to the given terminal. If that was a pseudoterminal master, send it to the slave.

Only a process with the CAP_SYS_ADMIN capability may do this.

If output was redirected already, then EBUSY is returned, but redirection can be stopped by using this ioctl with fd pointing at /dev/console or /dev/tty0.

On success, 0 is returned. On error, -1 is returned, and errno is set to indicate the error.

EBUSY

Output was redirected already.

EPERM

Insufficient permission.

Before Linux 2.6.10, anybody can do this as long as the output was not redirected yet; CAP_SYS_ADMIN was not necessary.