TCFLUSH(P) POSIX Programmer's Manual TCFLUSH(P)
tcflush - flush non-transmitted output data, non-read input data, or both
int tcflush(int fildes, int queue_selector);
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.
Upon successful completion, 0 shall be returned. Otherwise, -1 shall be returned and errno
set to indicate the error.
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.
tcdrain() , the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 11, General Ter-
minal Interface, <termios.h>, <unistd.h>
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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 TCFLUSH(P)