I have a laptop which has only one serial port.
I went into:
directory, and I found:
ttyS0 ttyS1 ttyS2 ttyS3
How do I know which of those "ttyS" refers to my serial port?
I think it's this command:
Running that on my own Linux box (which only has 1 Serial port) produces a single ttyS0 output line. Try it on your own, you will see what I mean.