# Config Overrides with Env Var Environment variables can override config values. By default the core will listen to conf values in this order: ``` 1. Environment variables 2. .conf file 3. Base values defined in the core ``` Environment variables keys are autogenerated based on the keys defined in .conf file. ```cpp // Example of conversions: // SomeConfig => SOME_CONFIG // myNestedConfig.opt1 => MY_NESTED_CONFIG_OPT_1 // LogDB.Opt.ClearTime => LOG_DB_OPT_CLEAR_TIME // GM.InGMList.Level => AC_GM_IN_GMLIST_LEVEL ``` Usage example Unix: ```sh $ export AC_DATA_DIR=/usr $ AC_WORLD_SERVER_PORT=8080 ./worldserver ``` Windows: ```ps > $env:AC_REALM_ID = '2'; .\worldserver ```