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, Copyright (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.opengroup.org/unix/online.html .