Connecting via serial with Arduino comand line Since inotool is dead, I'm trying to transition over to Arduino's built-in command line tool.

It seems largely equivalent, but the one feature it seems to be missing is a serial interface. e.g. Running ino serial would open a simple serial interface to the Arduino, providing invaluable debugging info from any Serial.print() statements.

How is this accomplished with the current Arduino command line tool?
If you are using linux, as I guess, you can look at this archwiki page. Even if is a wiki relative to archlinux OS some informations explained are LinuxOS independendent.

For your needs, you can use screen command. Here is an example: remember to substitute the serial port with the one wich arduino is connected (usually /dev/ttyACM* or /dev/ttyUSB*) and to specify the right baud rate.

screen /dev/ttyACM0 9600