tcdrain(3P)                                           tcdrain(3P)



     NAME
          tcdrain,  tcflow,  tcflush,  tcsendbreak  -   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 ac-
          tion.  If action is TCOOFF, output will be suspended.  If
          action is TCOON, suspended output will be restarted.  If ac-
          tion 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 writ-
          ten, 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.

     RETURN VALUE
          Upon successful completion, zero is returned.  Otherwise, -1
          is returned and errno is set to indicate the error.

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



     April, 1990                                                     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 ter-
                        minal.

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

          [EINTR]       tcdrain was interrupted by a signal.

     SEE ALSO
          termios(7P).







































     2                                                     April, 1990