title: How do the CLOCAL and CRTSCTS Flags in termios.c_cflag Affect the Serial Port?
body: <p>I want to configure a UART to use the Hardware Flow Control lines RTS and CTS in Linux. According to <a href="http://linux.die.net/man/3/termios" rel="noreferrer">http://linux.die.net/man/3/termios</a>, CRTSCTS enables RTS/CTS (hardware) flow control, and CLOCAL configures the serial port to ignore modem control lines. The 2 flags seem contradictory, how can you have hardware flow control enabled with CRTSCTS and ignore the lines with CLOCAL?</p>