TCSENDBREAK(3P) POSIX Programmer's Manual TCSENDBREAK(3P)PROLOG
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.
NAMEtcsendbreak — send a break for a specific duration
SYNOPSIS
#include <termios.h>
int tcsendbreak(int fildes, int duration);
DESCRIPTION
If the terminal is using asynchronous serial data transmission, tcsend‐
break() shall cause transmission of a continuous stream of zero-valued
bits for a specific duration. If duration is 0, it shall cause trans‐
mission of zero-valued bits for at least 0.25 seconds, and not more
than 0.5 seconds. If duration is not 0, it shall send zero-valued bits
for an implementation-defined period of time.
The fildes argument is an open file descriptor associated with a termi‐
nal.
If the terminal is not using asynchronous serial data transmission, it
is implementation-defined whether tcsendbreak() sends data to generate
a break condition or returns without taking any action.
Attempts to use tcsendbreak() from a process which is a member of a
background process group on a fildes 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 ignor‐
ing SIGTTOU signals, the process shall be allowed to perform the opera‐
tion, and no signal is sent.
RETURN VALUE
Upon successful completion, 0 shall be returned. Otherwise, −1 shall be
returned and errno set to indicate the error.
ERRORS
The tcsendbreak() function shall fail if:
EBADF The fildes argument is not a valid file descriptor.
EIO The process group of the writing process is orphaned, the call‐
ing thread is not blocking SIGTTOU, and the process is not
ignoring SIGTTOU.
ENOTTY The file associated with fildes is not a terminal.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
The Base Definitions volume of POSIX.1‐2008, Chapter 11, General Termi‐
nal Interface, <termios.h>
COPYRIGHT
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 Electri‐
cal 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 http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
files to man page format. To report such errors, see https://www.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 TCSENDBREAK(3P)
