Tribblix: manual page: tcsendbreak.3c

TCSENDBREAK(3C) Standard C Library Functions TCSENDBREAK(3C)

NAME

tcsendbreak - send a ``break'' for a specific duration

SYNOPSIS

#include <termios.h>

int tcsendbreak(int fildes, int duration);

DESCRIPTION

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.

RETURN VALUES

Upon successful completion, 0 is returned. Otherwise, -1 is returned
and errno is set to indicate the error.

ERRORS

The tcsendbreak() function will 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.