TCSENDBREAK(P) POSIX Programmer's Manual TCSENDBREAK(P)
tcsendbreak - send a break for a specific duration
int tcsendbreak(int fildes, int duration);
If the terminal is using asynchronous serial data transmission, tcsendbreak() shall cause
transmission of a continuous stream of zero-valued bits for a specific duration. If dura-
tion is 0, it shall cause transmission 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 terminal.
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 process is blocking or ignoring SIGTTOU sig-
nals, 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 errno
set to indicate the error.
The tcsendbreak() function shall fail if:
EBADF The fildes argument is not a valid file descriptor.
ENOTTY The file associated with fildes is not a terminal.
The tcsendbreak() function may fail if:
EIO The process group of the writing process is orphaned, and the writing process is
not ignoring or blocking SIGTTOU.
The following sections are informative.
The Base Definitions volume of IEEE Std 1003.1-2001, Chapter 11, General Terminal Inter-
face, <termios.h>, <unistd.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by
the Institute of Electrical and Electronics Engineers, Inc and The Open Group. 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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 TCSENDBREAK(P)