add better err msg

src/battery.c

@@ -17,11 +17,12 @@
  *************************************************************************** */
 
 int get_battery_level(const char *device_path, bool *is_charging) {
-  HANDLE hDevice = CreateFile(device_path, GENERIC_READ | GENERIC_WRITE,
-                              FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
-                              OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
-  if (hDevice == INVALID_HANDLE_VALUE) {
-    fprintf_s(stderr, "Failed to open device.\n");
+  HANDLE hDevice;
+  if ((hDevice = CreateFile(device_path, GENERIC_READ | GENERIC_WRITE,
+                            FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
+                            OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL)) ==
+      INVALID_HANDLE_VALUE) {
+    fprintf_s(stderr, "[%lu] Failed to open device.\n", GetLastError());
 
     return -1;
   }
@@ -33,7 +34,8 @@ int get_battery_level(const char *device_path, bool *is_charging) {
 
   // Send the report
   if (!HidD_SetFeature(hDevice, report, RAZER_REPORT_LEN)) {
-    fprintf_s(stderr, "Failed to send report to device.\n");
+    fprintf_s(stderr, "[%lu] Failed to send report to device.\n",
+              GetLastError());
 
     CloseHandle(hDevice);
     return -1;
@@ -41,7 +43,8 @@ int get_battery_level(const char *device_path, bool *is_charging) {
 
   // Read the response
   if (!HidD_GetFeature(hDevice, report, RAZER_REPORT_LEN)) {
-    fprintf_s(stderr, "Failed to read report from device.\n");
+    fprintf_s(stderr, "[%lu] Failed to read report from device.\n",
+              GetLastError());
 
     CloseHandle(hDevice);
     return -1;

src/helper.c

@@ -6,7 +6,7 @@
 #include <setupapi.h>
 #include <stdio.h>
 
-#define VID 0x1532
+#define VID_RAZER 0x1532
 
 void find_device_path(int pid, char *device_path) {
   GUID hidGuid;
@@ -15,7 +15,9 @@ void find_device_path(int pid, char *device_path) {
   HDEVINFO hDevInfo = SetupDiGetClassDevs(
       &hidGuid, NULL, NULL, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
   if (hDevInfo == INVALID_HANDLE_VALUE) {
-    fprintf_s(stderr, "Failed to get device information.\n");
+    fprintf_s(stderr, "[%lu] Failed to get any device information\n",
+              GetLastError());
+
     return;
   }
 
@@ -24,7 +26,7 @@ void find_device_path(int pid, char *device_path) {
 
   for (DWORD i = 0; SetupDiEnumDeviceInterfaces(hDevInfo, NULL, &hidGuid, i,
                                                 &deviceInterfaceData);
-       i++) {
+       ++i) {
     DWORD requiredSize;
     SetupDiGetDeviceInterfaceDetail(hDevInfo, &deviceInterfaceData, NULL, 0,
                                     &requiredSize, NULL);
@@ -35,6 +37,7 @@ void find_device_path(int pid, char *device_path) {
       fprintf_s(
           stderr,
           "Failed to allocated memory for PSP_DEVICE_INTERFACE_DETAIL_DATA.\n");
+
       return;
     }
     detailData->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);
@@ -44,21 +47,25 @@ void find_device_path(int pid, char *device_path) {
       HANDLE hDevice = CreateFile(
           detailData->DevicePath, GENERIC_READ | GENERIC_WRITE,
           FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
+
       if (hDevice != INVALID_HANDLE_VALUE) {
         // Get device attributes
         HIDD_ATTRIBUTES attributes;
         attributes.Size = sizeof(HIDD_ATTRIBUTES);
         if (HidD_GetAttributes(hDevice, &attributes)) {
           // Check VID and PID
-          if (attributes.VendorID == VID && attributes.ProductID == pid) {
+          if (attributes.VendorID == VID_RAZER && attributes.ProductID == pid) {
             strcpy(device_path, detailData->DevicePath);
+
             CloseHandle(hDevice);
             break;
           }
         }
+
         CloseHandle(hDevice);
       }
     }
+
     free(detailData);
   }
 

src/main.c

@@ -6,7 +6,7 @@
 
 int main(void) {
   char device_path[2048];
-  int min_len = 10;
+  unsigned long long min_len = 10;
 
   // Try wired
   find_device_path(USB_DEVICE_ID_RAZER_VIPER_ULTIMATE_WIRED, device_path);