#include <termios.h> int tcsendbreak(int fildes, int duration);
The fildes argument is an open file descriptor associated with a terminal.
If the terminal is using asynchronous serial data transmission, tcsendbreak() will cause transmission of a continuous stream of zero-valued bits for a specific duration. If duration is 0, it will 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 behaves in a way similar to tcdrain(3C).
If the terminal is not using asynchronous serial data transmission, it 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 will cause the process group to be sent a SIGTTOU signal. If the calling process is blocking or ignoring SIGTTOU signals, the process is allowed to perform the operation, and no signal is sent.
The tcsendbreak() function will fail if:
The tcsendbreak() function may fail if:
See attributes(5) for descriptions of the following attributes: