TCDRAIN(3P)                                         POSIX Programmer's Manual                                        TCDRAIN(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       tcdrain - wait for transmission of output

SYNOPSIS
       #include <termios.h>

       int tcdrain(int fildes);


DESCRIPTION
       The  tcdrain()  function  shall  block  until all output written to the object referred to by fildes is transmitted.  The
       fildes argument is an open file descriptor associated with a terminal.

       Any attempts to use tcdrain() 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.

RETURN VALUE
       Upon successful completion, 0 shall be returned. Otherwise, -1 shall be returned and errno set to indicate the error.

ERRORS
       The tcdrain() function shall fail if:

       EBADF  The fildes argument is not a valid file descriptor.

       EINTR  A signal interrupted tcdrain().

       ENOTTY The file associated with fildes is not a terminal.


       The tcdrain() 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.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       tcflush(), the Base Definitions volume of IEEE Std 1003.1-2001, Chapter  11,  General  Terminal  Interface,  <termios.h>,
       <unistd.h>

COPYRIGHT
       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,  Copy-
       right (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   original   Standard   can   be   obtained  online  at  http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                   TCDRAIN(3P)