Emulate windows registry by environment variables

src/game/common/system/asciistring.cpp

@@ -389,6 +389,27 @@ void Utf8String::To_Lower()
     Set(buf);
 }
 
+/**
+ * Converts this string to upper case
+ */
+void Utf8String::To_Upper()
+{
+    // Size specifically matches original code for compatibility.
+    char buf[MAX_TO_LOWER_BUF_LEN];
+
+    if (m_data == nullptr) {
+        return;
+    }
+
+    strcpy(buf, Peek());
+
+    for (char *c = buf; *c != '\0'; ++c) {
+        *c = toupper(*c);
+    }
+
+    Set(buf);
+}
+
 /**
  * @brief Convert any windows path separators to posix ('\' to '/').
  */

src/game/common/system/asciistring.h

@@ -126,6 +126,7 @@ class Utf8String
 
     void Trim();
     void To_Lower();
+    void To_Upper(); // Not in original code.
     void Remove_Last_Char();
 
     void Format(const char *format, ...);

src/game/common/system/registryget.cpp

@@ -90,7 +90,18 @@ bool Get_String_From_Registry(Utf8String subkey, Utf8String value, Utf8String &d
 
     return success;
 #else
-    return false;
+    Utf8String key = "CNC_ZH_";
+    key += value;
+    key.To_Upper();
+    captainslog_info(
+        "Get_String_From_Registry (environment) - looking in %s for key %s\n", key.Str(), value.Str());
+    const char *env_value = getenv(key.Str());
+    bool success = env_value != nullptr;
+    if (success) {
+        destination = env_value;
+    }
+
+    return success;
 #endif
 }
 
@@ -108,7 +119,18 @@ bool Get_String_From_Generals_Registry(Utf8String subkey, Utf8String value, Utf8
 
     return success;
 #else
-    return false;
+    Utf8String key = "CNC_GEN_";
+    key += value;
+    key.To_Upper();
+    captainslog_info(
+        "Get_String_From_Generals_Registry (environment) - looking in %s for key %s\n", key.Str(), value.Str());
+    const char *env_value = getenv(key.Str());
+    bool success = env_value != nullptr;
+    if (success) {
+        destination = env_value;
+    }
+
+    return success;
 #endif
 }