NAME
tcflush - flush non-transmitted output data, non-read input data, or
both
SYNOPSIS
#include <termios.h>
int tcflush(int fildes, int queue_selector);
DESCRIPTION
Upon successful completion, tcflush() shall discard data written to the
object referred to by fildes (an open file descriptor associated with a
terminal) but not transmitted, or data received but not read, depending
on the value of queue_selector:
* If queue_selector is TCIFLUSH, it shall flush data received but not
read.
* If queue_selector is TCOFLUSH, it shall flush data written but not
transmitted.
* If queue_selector is TCIOFLUSH, it shall flush both data received
but not read and data written but not transmitted.
Attempts to use tcflush() 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 tcflush() function shall fail if:
EBADF The fildes argument is not a valid file descriptor.
EINVAL The queue_selector argument is not a supported value.
ENOTTY The file associated with fildes is not a terminal.
The tcflush() 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
tcdrain() , the Base Definitions volume of IEEE Std 1003.1-2001,
Chapter 11, General Terminal Interface, <termios.h>, <unistd.h>
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 .