dprintf(filedescriptor,formatstring,variablelist).What is less well known is that you can also use dprintf, which is the file descriptor version of printf to write to the file descriptor. Writes len bytes of buffer to the file specified by the file descriptor. You can use the standard file descriptor writing function to send data: We have already used the write function without really discussing it, but sending data isn't the difficult part of using serial - receiving data is. If duration is not zero, it sends zero-valued bits for some implementation-defined length of time.

It doesn't correspond to any transmitted character because it is out of specification for the number of bits, stop bit and parity specified - the line is simply held low for a given time. If duration is zero, it transmits zero-valued bits for at least 0.25 seconds, and not more that 0.5 seconds. A break is an 'out of band' transmission needed to signal special conditions like a hard reset to some devices. Transmits a continuous stream of zero-valued bits for a specific duration. TCIOFLUSH flushes all data waiting to be processed TCOFLUSH flushes data written but not transmitted TCIFLUSH flushes data received but not read If you need to wait before sending any more data or reading a response this is the way to do it.ĭiscards data written to the object referred to by fd but not transmitted, or data received but not read, depending on the value of action: The Linux UART driver will accept large amounts of data and send it for you while your program gets on with something else and this is true even in blocking mode.

Waits until all of the data that has been written has been sent. There are some useful utility functions you need to know about:

Linux c serial port example