.\" Copyright 2002, Walter Harms <walter.harms@informatik.uni-oldenburg.de>
.\" Copyright 2002, Andries Brouwer <aeb@cwi.nl>
.\" Copyright 2024, Alejandro Colomar <alx@kernel.org>
.\"
.\" SPDX-License-Identifier: GPL-1.0-or-later
.\"
.TH TIOCSLCKTRMIOS 2const 2024-06-13 "Linux man-pages 6.9.1"
.SH NAME
TIOCGLCKTRMIOS,
TIOCSLCKTRMIOS
\-
locking the termios structre
.SH LIBRARY
Standard C library
.RI ( libc ", " \-lc )
.SH SYNOPSIS
.nf
.BR "#include <asm/termbits.h>" "  /* Definition of " TIOC*CLKTRMIOS " constants */"
.B #include <sys/ioctl.h>
.P
.BI "int ioctl(int " fd ", TIOCGLCKTRMIOS, struct termios *" argp );
.BI "int ioctl(int " fd ", TIOCSLCKTRMIOS, const struct termios *" argp );
.P
.B #include <asm/termbits.h>
.P
.B struct termios;
.fi
.SH DESCRIPTION
The
.I termios
structure of a terminal can be locked.
The lock is itself a
.I termios
structure, with nonzero bits or fields indicating a
locked value.
.TP
.B TIOCGLCKTRMIOS
Gets the locking status of the
.I termios
structure of the terminal.
.TP
.B TIOCSLCKTRMIOS
Sets the locking status of the
.I termios
structure of the terminal.
Only a process with the
.B CAP_SYS_ADMIN
capability can do this.
.SH RETURN VALUE
On success,
0 is returned.
On error,
\-1 is returned, and
.I errno
is set to indicate the error.
.SH ERRORS
.TP
.B EPERM
Insufficient permission.
.SH CAVEATS
Please note that
.B struct termios
from
.I <asm/termbits.h>
is different and incompatible with
.B struct termios
from
.IR <termios.h> .
These ioctl calls require
.B struct termios
from
.IR <asm/termbits.h> .
.SH SEE ALSO
.BR ioctl (2),
.BR ioctl_tty (2),
.BR TCSETS (2const)