Relevant to 2013 onwards involving udev and checking ink levels on older printers.
The standard GutenPrint libraries and drivers used by CUPS for printing can talk to Epson Printers well enough so that general printing can take place, test pages, change of print quality etc. However there is no decent means for returning current Ink levels.
There are two programs that allow you to do this – ‘ink’ and ‘escputil’.
These utilities were built when HAL was the dominant hardware-path-allocation tool. Now udev is used. However udev paths can seem convoluted, confusing and unecessarily long. Some guides say that in order to interface with older devices you need to go down /sys/devices/usb/0:0:0:1/1:0:0/-onwards-/
So when using commands like ‘ink’, you don’t know where to point it…
You need to point them at: /dev/usb/lp0 | lp1 | lp2 etc. Why people don’t know to go here, I’ve no idea, but here it is.
The exact commands needed for Ink and Escputil can be found on their websites. – I think ink’s is
sudo ink -d /dev/usb/lp0