Dear maintainers, I apologize if there was a better source for the information I search, than writing to you (I imagine you are busy enough...). I try to write a C function to identify the available real serial (UART) ports on a PC without trying to open them, but I cannot figure out the best way. I also googled (duckduckgo-ed :) ) the internet, but no real answers. I tried 2 approaches: one by using libudev and the other by reading information directly from /sys/class/tty/ file system (and following the symlinks). In both approaches I can easily isolate the tty subsystem and list devices, but in the end I need to open the remaining ports in order to check their status. The closest I came was by reading /sys/class/tty and eliminating all virtual entries, but I still remain with up to 32 serial ports of type serial8250, depending on linux distribution. The USB-serial converters are easy to identify, but with built-in serial ports it's not that easy.
Please tell what is the right way to find the available serial ports on a system, without trying to open them all. Thank you! Best regards, Cristian
