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(5) for descriptions of the  following  attri-
     butes:

     ______________________________________________________________
    |       ATTRIBUTE TYPE        |        ATTRIBUTE VALUE        |
    |_____________________________|_______________________________|
    | MT-Level                    | MT-Safe, and Async-Signal-Safe|
    |_____________________________|_______________________________|

SEE ALSO

     tcdrain(3C), attributes(5), termio(7I)