TIOCCONS(2const) — Linux manual page

TIOCCONS(2const)                                         TIOCCONS(2const)

NAME         top

       TIOCCONS - redirecting console output

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

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

       int ioctl(int fd, TIOCCONS);

DESCRIPTION         top

       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         top

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

ERRORS         top

       EBUSY  Output was redirected already.

       EPERM  Insufficient permission.

HISTORY         top

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

SEE ALSO         top

       ioctl(2), ioctl_tty(2)

COLOPHON         top

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Linux man-pages 6.15            2025-05-17               TIOCCONS(2const)

Pages that refer to this page: ioctl_tty(2)

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