TIOCCONS - redirecting console output

NAME LIBRARY SYNOPSIS DESCRIPTION RETURN VALUE ERRORS HISTORY SEE ALSO

NAME

TIOCCONS − redirecting console output

LIBRARY

Standard C library (libc, −lc)

SYNOPSIS

#include <asm/termbits.h> /* Definition of TIOCCONS */
#include <sys/ioctl.h>

int ioctl(int fd, TIOCCONS);

DESCRIPTION

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.

RETURN VALUE

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

ERRORS

	EBUSY		Output was redirected already.
	EPERM		Insufficient permission.

HISTORY

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