tcflush(3p) — Linux manual page

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
       corresponding 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 terminal shall cause the process group to be sent a
       SIGTTOU signal.  If the calling thread is blocking SIGTTOU
       signals or the process is 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.

       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(3p)

       The Base Definitions volume of POSIX.1‐2017, Chapter 11, General
       Terminal Interface, termios.h(0p)

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 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 .

       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               2017                       TCFLUSH(3P)

Pages that refer to this page: termios.h(0p), tcdrain(3p)

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