SYNOPSIS
#include <termios.h>
int tcsendbreak(int fildes, int duration);
DESCRIPTION
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 duration 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 signals, the process shall be allowed to perform the operation, 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.
- 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.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
COPYRIGHT
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 original Standard can be obtained online at http://www.opengroup.org/unix/online.html .