feat: Add argument to check library

This mode allows checking if the DLL can be found, without having to
create any kind of dummy data or parse stderr.

oodle-cli.cpp

@@ -30,6 +30,7 @@ void usage() {
         "\n"
         "Options:\n"
         "  -v  Increase Oodle's verbosity. May be specified up to three times.\n"
+        "  -c  Only check if the library can be found and used.\n"
         "\n"
         "The following environmental variables are recognized:\n"
         "  DLL_SEARCH_PATH: A color (':') separated list of directories to search for the Oodle library. May be relative to the current working directory.\n";
@@ -38,6 +39,7 @@ void usage() {
 int main(int argc, char* argv[])
 {
     int verbosity = 0;
+    bool check_lib = FALSE;
     int i = 1;
 
     for (; i < argc; i++) {
@@ -51,6 +53,9 @@ int main(int argc, char* argv[])
             usage();
             return 0;
         }
+        else if (strcmp(arg, "-c") == 0) {
+            check_lib = TRUE;
+        }
         else if (strcmp(arg, "-v") == 0) {
             verbosity++;
         }
@@ -96,12 +101,16 @@ int main(int argc, char* argv[])
         return 1;
     }
 
-    auto decompress = (decltype(OodleLZ_Decompress)*)GetProcAddress((HMODULE)hDLL, "OodleLZ_Decompress");
+    auto decompress = reinterpret_cast<decompress_func>(GetProcAddress((HMODULE)hDLL, "OodleLZ_Decompress"));
     if (decompress == NULL) {
         std::cerr << "ERROR: The library is incompatible!\n";
         return 1;
     }
 
+    if (check_lib) {
+        std::cout << "INFO: '" << LIB_FILE << "' found and loaded.\n";
+        return 0;
+    }
 
     if (argc - i < 3) {
         std::cerr << "ERROR: Arguments missing!\n\n";