TCFLUSH(3C) Standard C Library Functions TCFLUSH(3C)

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() discards 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:

o If queue_selector is TCIFLUSH it flushes data received but not
read.

o If queue_selector is TCOFLUSH it flushes data written but not
transmitted.

o If queue_selector is TCIOFLUSH it flushes 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, 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 tcflush() function will 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.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+--------------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+--------------------------------+
|Interface Stability | Standard |
+--------------------+--------------------------------+
|MT-Level | MT-Safe, and Async-Signal-Safe |
+--------------------+--------------------------------+

SEE ALSO

tcdrain(3C), termio(4I), attributes(7), standards(7)

August 14, 2002 TCFLUSH(3C)