Add handling of env variables

src/app/app.cpp

@@ -220,6 +220,30 @@ CSoundInterface* CApplication::GetSound()
     return m_sound.get();
 }
 
+void CApplication::LoadEnvironmentVariables()
+{
+    auto dataDir = m_systemUtils->GetEnvVar("COLOBOT_DATA_DIR");
+    if (!dataDir.empty())
+    {
+        m_pathManager->SetDataPath(dataDir);
+        GetLogger()->Info("Using data dir (based on environment variable): '%s'\n", dataDir.c_str());
+    }
+
+    auto langDir = m_systemUtils->GetEnvVar("COLOBOT_LANG_DIR");
+    if (!langDir.empty())
+    {
+        m_pathManager->SetLangPath(langDir);
+        GetLogger()->Info("Using lang dir (based on environment variable): '%s'\n", langDir.c_str());
+    }
+
+    auto saveDir = m_systemUtils->GetEnvVar("COLOBOT_SAVE_DIR");
+    if (!saveDir.empty())
+    {
+        m_pathManager->SetSavePath(saveDir);
+        GetLogger()->Info("Using save dir (based on environment variable): '%s'\n", saveDir.c_str());
+    }
+}
+
 ParseArgsStatus CApplication::ParseArguments(int argc, char *argv[])
 {
     enum OptionType
@@ -286,15 +310,18 @@ ParseArgsStatus CApplication::ParseArguments(int argc, char *argv[])
                 GetLogger()->Message("\n");
                 GetLogger()->Message("%s\n", COLOBOT_FULLNAME);
                 GetLogger()->Message("\n");
-                GetLogger()->Message("List of available options:\n");
+                GetLogger()->Message("List of available options and environment variables:\n");
                 GetLogger()->Message("  -help               this help\n");
                 GetLogger()->Message("  -debug modes        enable debug modes (more info printed in logs; see code for reference of modes)\n");
                 GetLogger()->Message("  -runscene sceneNNN  run given scene on start\n");
                 GetLogger()->Message("  -scenetest          win every mission right after it's loaded\n");
                 GetLogger()->Message("  -loglevel level     set log level to level (one of: trace, debug, info, warn, error, none)\n");
                 GetLogger()->Message("  -langdir path       set custom language directory path\n");
+                GetLogger()->Message("                      environment variable: COLOBOT_LANG_DIR\n");
                 GetLogger()->Message("  -datadir path       set custom data directory path\n");
+                GetLogger()->Message("                      environment variable: COLOBOT_DATA_DIR\n");
                 GetLogger()->Message("  -savedir path       set custom save directory path (must be writable)\n");
+                GetLogger()->Message("                      environment variable: COLOBOT_SAVE_DIR\n");
                 GetLogger()->Message("  -mod path           load datadir mod from given path\n");
                 GetLogger()->Message("  -resolution WxH     set resolution\n");
                 GetLogger()->Message("  -headless           headless mode - disables graphics, sound and user interaction\n");

src/app/app.h

@@ -164,7 +164,9 @@ public:
     CSoundInterface* GetSound();
 
 public:
-    //! Parses commandline arguments
+    //! Loads some data from environment variables
+    void LoadEnvironmentVariables();
+    //! Parses commandline arguments (they take priority)
     ParseArgsStatus ParseArguments(int argc, char *argv[]);
     //! Initializes the application
     bool        Create();

src/app/main.cpp

@@ -172,6 +172,8 @@ int main(int argc, char *argv[])
     int code = 0;
     CApplication app(systemUtils.get()); // single instance of the application
 
+    app.LoadEnvironmentVariables();
+
     ParseArgsStatus status = app.ParseArguments(argc, argv);
     if (status == PARSE_ARGS_FAIL)
     {

src/app/pathman.cpp

@@ -41,7 +41,7 @@ CPathManager::CPathManager(CSystemUtils* systemUtils)
     : m_dataPath(systemUtils->GetDataPath())
     , m_langPath(systemUtils->GetLangPath())
     , m_savePath(systemUtils->GetSaveDir())
-    , m_modAutoloadDir{ m_dataPath + "/mods", m_savePath + "/mods" }
+    , m_modAutoloadDir{}
     , m_mods{}
 {
 }
@@ -130,6 +130,10 @@ void CPathManager::InitPaths()
 {
     GetLogger()->Info("Data path: %s\n", m_dataPath.c_str());
     GetLogger()->Info("Save path: %s\n", m_savePath.c_str());
+
+    m_modAutoloadDir.push_back(m_dataPath + "/mods");
+    m_modAutoloadDir.push_back(m_savePath + "/mods");
+
     if (!m_modAutoloadDir.empty())
     {
         GetLogger()->Info("Mod autoload dirs:\n");

src/common/system/system.cpp

@@ -210,3 +210,8 @@ std::string CSystemUtils::GetSaveDir()
 {
     return "./saves";
 }
+
+std::string CSystemUtils::GetEnvVar(const std::string& str)
+{
+    return std::string();
+}

src/common/system/system.h

@@ -139,6 +139,9 @@ public:
     //! Returns the save dir location
     virtual std::string GetSaveDir();
 
+    //! Returns environment variable
+    virtual std::string GetEnvVar(const std::string &str);
+
     //! Sleep for given amount of microseconds
     virtual void Usleep(int usecs) = 0;
 

src/common/system/system_linux.cpp

@@ -126,6 +126,18 @@ std::string CSystemUtilsLinux::GetSaveDir()
 #endif
 }
 
+std::string CSystemUtilsLinux::GetEnvVar(const std::string& name)
+{
+    char* envVar = getenv(name.c_str());
+    if (envVar != nullptr)
+    {
+
+        GetLogger()->Trace("Detected environment variable %s = %s\n", name.c_str(), envVar);
+        return std::string(envVar);
+    }
+    return "";
+}
+
 void CSystemUtilsLinux::Usleep(int usec)
 {
     usleep(usec);

src/common/system/system_linux.h

@@ -45,6 +45,8 @@ public:
 
     std::string GetSaveDir() override;
 
+    std::string GetEnvVar(const std::string& name) override;
+
     void Usleep(int usec) override;
 
 private:

src/common/system/system_macosx.cpp

@@ -113,6 +113,12 @@ std::string CSystemUtilsMacOSX::GetSaveDir()
 #endif
 }
 
+std::string CSystemUtilsMacOSX::GetEnvVar(const std::string& str)
+{
+    // TODO: I have no Mac
+    return std::string();
+}
+
 void CSystemUtilsMacOSX::Usleep(int usec)
 {
     usleep(usec);

src/common/system/system_macosx.h

@@ -36,6 +36,8 @@ public:
     std::string GetLangPath() override;
     std::string GetSaveDir() override;
 
+    std::string GetEnvVar(const std::string& str) override;
+
     void Usleep(int usec) override;
 
 private:

src/common/system/system_windows.cpp

@@ -131,6 +131,22 @@ std::string CSystemUtilsWindows::GetSaveDir()
 #endif
 }
 
+std::string CSystemUtilsWindows::GetEnvVar(const std::string& name)
+{
+    std::wstring wname(name.begin(), name.end());
+    wchar_t* envVar = _wgetenv(wname.c_str());
+    if (envVar == nullptr)
+    {
+        return "";
+    }
+    else
+    {
+        std::string var = UTF8_Encode(std::wstring(envVar));
+        GetLogger()->Trace("Detected environment variable %s = %s\n", name.c_str(), var.c_str());
+        return var;
+    }
+}
+
 void CSystemUtilsWindows::Usleep(int usec)
 {
    LARGE_INTEGER ft;

src/common/system/system_windows.h

@@ -43,6 +43,8 @@ public:
 
     std::string GetSaveDir() override;
 
+    std::string GetEnvVar(const std::string& name) override;
+
     void Usleep(int usec) override;
 
 public: