Section: POSIX Programmer's Manual (3P)
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
--- send a break for a specific duration
int tcsendbreak(int fildes, int duration);
If the terminal is using asynchronous serial data transmission,
shall cause transmission of a continuous stream of zero-valued bits for
a specific duration. If
is 0, it shall cause transmission of zero-valued bits for at least 0.25
seconds, and not more than 0.5 seconds. If
is not 0, it shall send zero-valued bits for an
implementation-defined period of time.
argument is an open file descriptor associated with a terminal.
If the terminal is not using asynchronous serial data transmission, it
is implementation-defined whether
sends data to generate a break condition or returns without taking any
Attempts to use
from a process which is a member of a background process group on a
associated with its controlling terminal shall cause the process group
to be sent a SIGTTOU signal.
If the calling thread is blocking SIGTTOU signals or the process is
ignoring SIGTTOU signals, the process shall be allowed to perform the
operation, and no signal is sent.
Upon successful completion, 0 shall be returned. Otherwise, -1 shall
be returned and
set to indicate the error.
function shall fail if:
argument is not a valid file descriptor.
The process group of the writing process is orphaned, the calling thread
is not blocking SIGTTOU, and the process is not ignoring SIGTTOU.
The file associated with
is not a terminal.
The following sections are informative.
The Base Definitions volume of POSIX.1-2008,
, General Terminal Interface,
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
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