I do have an Arduino project that does stuff and then sends results out over it's serial port to a computer running Linux. This is a RS232 connection, 9600 Baud, connected either to a 9-Pin COM Port or using a USB/RS232 adapter (which in the end is the same any way).
Now, I can build my own reader using Minicom and reading from /dev/ttyS0 directly, but before I build my own solution, I wonder if there's already some kind of common standard - common sense tells me that in the decades of *NIX, someone must have already built something. But so far, I've mostly found information about manually reading or using the AT command set, which really doesn't apply here.
Something like "syslog over RS232" or so. I'm flexible in my data structure, and using some standard mechanism will allow other tools to also hook into it. I don't want to build the receiving software myself if there's already some standard software, and the eventual consumer of the data can then just pick it up from whatever standard place.
Addition: The data itself is essentially sensor data (got a few temperature sensors connected, and there are some buttons to turn on/off functionality) that I'm thinking of eventually sending as some OpenMetrics format - but as said, I'm pretty flexible and can do Arduino > RS232 > Linux > MyOwnConverter > EventualConsumer with an intermediary standard format (preferably human readable). The Linux side just needs to receive and store, the processing is then handled by an actual custom tool, I just prefer to have the "receive and store" part covered by existing tooling if feasible.