keyboard-reader/keyboard-reader.go

package main

import (
	"flag"
	udev "github.com/farjump/go-libudev"
	"keyboard-reader/evdev"
	"log"
	"os"
	"time"
)

const bufferLength = 32

func main() {
	device := flag.String("dev", "", "Keyboard device")
	vendor := flag.String("vendor", "", "Device vendor")
	model := flag.String("model", "", "Device id model")
	list := flag.Bool("list", false, "List input devices")
	nospace := flag.Bool("nospace", false, "Ignore spaces")
	connectorId := flag.Uint("connector", 0, "Connector id")
	wait := flag.Int("timeout", 5, "Http timeout, sec")
	url := flag.String("url", "http://localhost:8914/state/idTag", "Endpoint url")

	flag.Parse()

	if *list {
		if devs, err := getUdevEnumerate().Devices(); err != nil {
			log.Printf("Can't list devicies: %e", err)
		} else {
			for _, dev := range devs {
				log.Println(dev.Properties())
			}
		}
	}

	if len(*vendor) == 0 && len(*device) == 0 && len(*model) == 0 && !*list {
		flag.Usage()
	}

	if len(*vendor) > 0 {
		device = getDevByProperty(*vendor, "ID_VENDOR")
	}

	if len(*model) > 0 {
		device = getDevByProperty(*model, "ID_MODEL")
	}

	if device == nil || len(*device) == 0 {
		log.Println("Keyboard device not selected")
		os.Exit(1)
	}

	var dev *evdev.InputDevice
	var events []evdev.InputEvent
	var err error

	// Open our argv as a device and a file, so we can get the file descriptor.
	if dev, err = evdev.Open(*device, bufferLength); err != nil {
		// If the device can't be opened, spit out an error and exit.
		log.Printf("Unable to open input device: %s\n", *device)
		os.Exit(1)
	}
	defer dev.Close()

	if err = dev.Grab(); err != nil {
		log.Printf("Can't grab input from device: %s, error: %e\n", *device, err)
		os.Exit(2)
	}
	defer dev.Release()

	client := NewRest(*connectorId, *url, time.Duration(*wait)*time.Second, *nospace)

	// Run an infinite loop.
	for {
		// Read the device events.
		if events, err = dev.Read(); err != nil {
			log.Printf("Can't read input from device: %s, error: %e\n", *device, err)
			os.Exit(3)
		}

		// Iterate through the events.
		for _, event := range events {
			if r, ok := event.GetKey(); ok {
				client.Send(r)
			}
		}
	}
}

func getDevByProperty(value string, property string) *string {
	e := getUdevEnumerate()
	e.AddMatchProperty(property, value)

	if devices, err := e.Devices(); err == nil {
		for _, item := range devices {
			if name, found := item.Properties()["DEVNAME"]; found {
				log.Printf("Found device by %s: %s\n", property, name)
				return &name
			}
		}
	}
	return nil
}

func getUdevEnumerate() *udev.Enumerate {
	// Create Udev and Enumerate
	u := udev.Udev{}
	e := u.NewEnumerate()
	e.AddMatchSysname("event*")
	return e
}