posix man page for tcflush

TCFLUSH(3P)						     POSIX Programmer's Manual						       TCFLUSH(3P)

PROLOG
       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

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 termi-
       nal shall cause the process group to be sent a SIGTTOU signal.  If the calling thread is blocking SIGTTOU signals or the process is  ignor-
       ing 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.

       EIO    The  process  group  of the writing process is orphaned, the calling thread is not blocking SIGTTOU, and the process is not ignoring
	      SIGTTOU.

       ENOTTY The file associated with fildes is not a terminal.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       tcdrain()

       The Base Definitions volume of POSIX.1-2008, Chapter 11, General Terminal Interface, <termios.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technol-
       ogy  --	Portable  Operating  System  Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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 Stan-
       dard is the referee document. The original Standard can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE
/The Open Group						       2013							       TCFLUSH(3P)