tcdrain(3P)                                           tcdrain(3P)



NAME
     tcdrain, tcflow, tcflush, tcsendbreak - provide line control
     functions

SYNOPSIS
     #include <termios.h>

     int tcdrain(fildes)
     int fildes;

     int tcflow(fildes,action)
     int fildes, action;

     int tcflush(fildes,queue_selector)
     int fildes, queue_selector;

     int tcsendbreak(fildes,duration)
     int fildes, duration;

DESCRIPTION
     tcdrain causes the process to wait until all output written
     to the object indicated by fildes has been transmitted.

     tcflow will suspend transmission or reception of data on the
     object indicated by fildes, depending on the value of
     action.  If action is TCOOFF, output will be suspended.  If
     action is TCOON, suspended output will be restarted.  If
     action is TCIOF, input will be suspended.  If action is
     TCION, suspended input will be restarted.

     tcflush will discard data written to the object indicated by
     fildes but not transmitted, or data received but not read,
     depending on the value of queue_selector.  If queue_selector
     is TCIFLUSH, data received, but not read, will be flushed.
     If queue_selector is TCOFLUSH, data written, but not
     transmitted, will be flushed.  If queue_selector is
     TCIOFLUSH, both data received, but not read, and data
     written, but not transmitted, will be flushed.

     tcsendbreak will assert a break condition on the serial line
     associated with fildes depending on the value of duration.
     If duration is zero, the break condition will be asserted
     for 0.25 seconds.  If duration is not zero, no break will be
     sent.

STATUS MESSAGES AND VALUES
     Upon successful completion, zero is returned.  Otherwise, -1
     is returned and errno is set to indicate the error.

     If any of the following conditions occur, -1 will be
     returned and errno will be set to the corresponding value.




January 1992                                                    1

tcdrain(3P)                                           tcdrain(3P)



     EBADF
          fildes is not a valid file descriptor.

     EINVAL
          The device does not support the function or if the
          function called was tcflush, queue_selector is invalid.

     ENOTTY
          The file associated with fildes is not a terminal.

     In addition to those listed already, tcdrain will report the
     following error.

     EINTR
          tcdrain was interrupted by a signal.

SEE ALSO
     termios(7P)





































2                                                    January 1992