Cleanup

lsusb/main.go

@@ -24,54 +24,17 @@ func main() {
 	ctx.Debug(*debug)
 
 	// ListDevices is used to find the devices to open.
-	devs, err := ctx.ListDevices(func(bus, addr int, desc *usb.Descriptor) bool {
-		// After inspecting the descriptor, return true or false depending on whether
-		// the device is "interesting" or not.  Any descriptor for which true is returned
-		// generates a DeviceInfo which is retuned in a slice.
-		return true
-	})
-
-	// All DeviceInfo returned from ListDevices must be closed.
-	defer func() {
-		for _, d := range devs {
-			d.Close()
-		}
-	}()
-
-	// ListDevices can occaionally fail, so be sure to check its return value.
-	if err != nil {
-		log.Fatalf("list: %s", err)
-	}
-
-	for _, dev := range devs {
-		// The descriptor (which contains useful information) can always be obtained again
-		// from a DeviceInfo.
-		desc, err := dev.Descriptor()
-		if err != nil {
-			log.Printf("desc: %s", err)
-			continue
-		}
-
-		// The DeviceInfo contains the bus number and bus address of the device.
-		bus := dev.BusNumber()
-		addr := dev.Address()
-
+	devs, err := ctx.ListDevices(func(desc *usb.Descriptor) bool {
 		// The usbid package can be used to print out human readable information.
-		fmt.Printf("%03d:%03d %s\n", bus, addr, usbid.Describe(desc))
+		fmt.Printf("%03d.%03d %s\n", desc.Bus, desc.Address, usbid.Describe(desc))
 		fmt.Printf("  Protocol: %s\n", usbid.Classify(desc))
 
-		// The configurations can be examined from the DeviceInfo, though they can only
+		// The configurations can be examined from the Descriptor, though they can only
 		// be set once the device is opened.  All configuration references must be closed,
 		// to free up the memory in libusb.
-		cfgs, err := dev.Configurations()
-		if err != nil {
-			log.Printf("  - configs: %s", err)
-			continue
-		}
-
-		// This loop just uses more of the built-in and usbid pretty printing to list
-		// the USB devices.
-		for _, cfg := range cfgs {
+		for _, cfg := range desc.Configs {
+			// This loop just uses more of the built-in and usbid pretty printing to list
+			// the USB devices.
 			fmt.Printf("  %s:\n", cfg)
 			for _, alt := range cfg.Interfaces {
 				fmt.Printf("    --------------\n")
@@ -86,7 +49,27 @@ func main() {
 			fmt.Printf("    --------------\n")
 		}
 
-		// To actually interact with a device, DevInfo.Open() returns a device handle
-		// which can be used to do more I/O with the device and its endpoints.
+		// After inspecting the descriptor, return true or false depending on whether
+		// the device is "interesting" or not.  Any descriptor for which true is returned
+		// opens a Device which is retuned in a slice (and must be subsequently closed).
+		return false
+	})
+
+	// All Devices returned from ListDevices must be closed.
+	defer func() {
+		for _, d := range devs {
+			d.Close()
+		}
+	}()
+
+	// ListDevices can occaionally fail, so be sure to check its return value.
+	if err != nil {
+		log.Fatalf("list: %s", err)
+	}
+
+	for _, dev := range devs {
+		// Once the device has been selected from ListDevices, it is opened
+		// and can be interacted with.
+		_ = dev
 	}
 }