The Open Group Base Specifications Issue 6
IEEE Std 1003.1, 2003 Edition
Copyright © 2001-2003 The IEEE and The Open Group, All Rights reserved.

NAME

tcsendbreak - 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, 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.

SEE ALSO

The Base Definitions volume of IEEE Std 1003.1-2001, Chapter 11, General Terminal Interface, <termios.h>, <unistd.h>

CHANGE HISTORY

First released in Issue 3. Included for alignment with the POSIX.1-1988 standard.

Issue 6

The following new requirements on POSIX implementations derive from alignment with the Single UNIX Specification:

End of informative text.
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