Unless I'm missing something, there appears to be no simple way in *NIX to read from a serial port directly into a file
I had imagined something as simple as
cat /dev/ttyX > file but apparently not
Does anyone know a trick that I'm missing?
If you're just trying to capture data from a serial port, Minicom might work. I believe it supports logging to a file.
I thought doing a cat /dev/ttySx would work as well...are you sure it's mapped to the proper serial port? Is something else not allowing the device file to be opened? What happens if you just cat the file instead of redirecting it?