The
tcdrain function waits until all output written to the terminal referenced by
fd has been transmitted to the terminal.
The
tcflow function suspends transmission of data to or the reception of data from the terminal referenced by
fd depending on the value of
action. The value of
action must be one of the following:
TCOON
Restart suspended output.
TCIOFF
Transmit a STOP character, which is intended to cause the terminal to stop transmitting data to the system. (See the description of IXOFF in the ‘Input Modes' section of
termios(4)).
TCION
Transmit a START character, which is intended to cause the terminal to start transmitting data to the system. (See the description of IXOFF in the ‘Input Modes' section of
termios(4)).
The
tcflush function discards any data written to the terminal referenced by
fd which has not been transmitted to the terminal, or any data received from the terminal but not yet read, depending on the value of
action. The value of
action must be one of the following:
TCIFLUSH
Flush data received but not read.
TCOFLUSH
Flush data written but not transmitted.
TCIOFLUSH
Flush both data received but not read and data written but not transmitted.
The
tcsendbreak function transmits a continuous stream of zero-valued bits for four-tenths of a second to the terminal referenced by
fd. The
len parameter is ignored in this implementation.