TCFLUSH(3) Library Functions Manual TCFLUSH(3)

tcflush — flush non-transmitted output data, non-read input data, or both

#include <termios.h>

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 set to indicate the error.

The tcflush () function shall fail if:

The fildes argument is not a valid file descriptor.
The queue_selector argument is not a supported value.
The file associated with fildes is not a terminal.

The tcflush () function may fail if:

The process group of the writing process is orphaned, and the writing process is not ignoring or blocking SIGTTOU.

None.

None.

None.

None.

tcdrain(3)

XBD V1_chap11(7) , <termios.h>

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

The Open Group Corrigendum U035/1 is applied. In the ERRORS and APPLICATION USAGE sections, references to tcflow(3) are replaced with tcflush ().

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

  • In the DESCRIPTION, the final paragraph is no longer conditional on _POSIX_JOB_CONTROL. This is a FIPS requirement.
  • The [EIO] error is added.

January 1, 2008 posix.fail