Updated Makefile for usbscale.c

Makefile

@@ -2,5 +2,11 @@ LD=-lusb-1.0
 CC=gcc
 CFLAGS=-Os
 
+usbscale: usbscale.c scales.h
+	$(CC) usbscale.c -o usbscale $(CFLAGS) $(LD)
+
+lsscale: lsscale.c scales.h
+	$(CC) lsscale.c -o lsscale $(CFLAGS) $(LD)
+
 lsusb: lsusb.c
 	$(CC) lsusb.c -o lsusb $(CFLAGS) $(LD)

scales.h

@@ -0,0 +1,13 @@
+/*
+ * This file is a list of all currently-recognized scales,
+ * by their vendor and product IDs.
+ *
+ * For example, the USB product 1446:6173 becomes {0x1446, 0x6173}
+ */
+
+// array length
+int scalesc = 1;
+
+uint16_t scales[][] = {
+    {0x1446, 0x6173}    // Stamps.com USB scale
+}

usbscale.c

@@ -0,0 +1,74 @@
+#include <stdio.h>
+#include <sys/types.h>
+
+#include <libusb-1.0/libusb.h>
+#include "scales.h"
+
+#define DEBUG 1
+
+static void print_devs(libusb_device **devs)
+{
+	
+	if(DEBUG)
+		libusb_set_debug(null, 3);
+
+	libusb_device *dev;
+	int i = 0;
+
+	while ((dev = devs[i++]) != NULL) {
+		struct libusb_device_descriptor desc;
+		int r = libusb_get_device_descriptor(dev, &desc);
+		if (r < 0) {
+			fprintf(stderr, "failed to get device descriptor");
+			return;
+		}
+        int i;
+        for (i = 0; i < scalesc; i++) {
+            if(desc.idVendor  == scales[i][0] && 
+               desc.idProduct == scales[i][1]) {
+				if(DEBUG) {
+					printf("Found scale %04x:%04x (bus %d, device %d)\n",
+                    desc.idVendor, desc.idProduct,
+                    libusb_get_bus_number(dev), libusb_get_device_address(dev));
+
+					printf("It has descriptors:\n\tmanufc: %d\n\tprodct: %d\n\tserial: %d\n",
+							desc.iManufacturer,
+							desc.iProduct,
+							desc.iSerialNumber);
+				}
+                unsigned char string[256];
+
+                libusb_device_handle* hand;
+
+                libusb_open(dev, &hand);
+
+                r = libusb_get_string_descriptor_ascii(hand, desc.iManufacturer,
+                        string, 256);
+                printf("Manufacturer: %s\n", string);
+                break;
+            }
+        }
+	}
+}
+
+int main(void)
+{
+	libusb_device **devs;
+	int r;
+	ssize_t cnt;
+
+	r = libusb_init(NULL);
+	if (r < 0)
+		return r;
+
+	cnt = libusb_get_device_list(NULL, &devs);
+	if (cnt < 0)
+		return (int) cnt;
+
+	print_devs(devs);
+	libusb_free_device_list(devs, 1);
+
+	libusb_exit(NULL);
+	return 0;
+}
+