diff --git a/index.js b/index.js
index 7a37a8a..3e0ab50 100644
--- a/index.js
+++ b/index.js
@@ -3,15 +3,13 @@ const path = require('path')
 const commander = require('commander')
 const deepmerge = require('deepmerge')
 
-const my = { secretKeys:[] }
-
 module.exports = {
-  mergeConfig({rawConfig={}, envarFiles=['./envar-base-basic.js', './envar-base-custom.js', './envar-base-secret.js']} = {}) {
+  mergeEnvar({rawEnvar={}, envarFiles=['./envar-base-basic.js', './envar-base-custom.js', './envar-base-secret.js'], hasCommander=true} = {}) {
     if (!global.envar) {
-      global.envar = rawConfig
+      global.envar = rawEnvar
       // 不知为何，必须定义成全局变量，才能保证多次require只执行一次。
 
-      console.info('<<<<<<<< Collecting Environment Configuration <<<<<<<<')
+      console.info('<<<<<<<< Configuring Environment Variables <<<<<<<<')
 
       console.info('- Loading Configuration Files (读取配置文件)')
       
@@ -31,28 +29,30 @@ module.exports = {
         delete global.envar.ENV_PRODUCTION
       }
 
-      console.info('- Loading Command Line Parameters (载入命令行参数)')
-      commander.version(global.envar.Base_Version || '0.0.1', '-v, --version') // 默认是 -V。如果要 -v，就要加 '-v --version'
-      for (let [key, param, desc] of global.envar.Commander_Option_List || []) {
-        commander.option(param, `${desc} Default = "${global.envar[key]}"`)
-      }
-      commander.parse(process.argv)
-      delete global.envar.Commander_Option_List // do not print Commander_Option_List to console
+      if (hasCommander) {
+        console.info('- Loading Command Line Parameters (载入命令行参数)')
+        commander.version(global.envar.Base_Version || '0.0.1', '-v, --version') // 默认是 -V。如果要 -v，就要加 '-v --version'
+        for (let [key, param, desc] of global.envar.Commander_Option_List || []) {
+          commander.option(param, `${desc} Default = "${global.envar[key]}"`)
+        }
+        commander.parse(process.argv)
+        delete global.envar.Commander_Option_List
 
-      console.log('- Merging Command Line Parameters into Configuration (把命令行参数值合并入配置)')
-      for (let key in commander) {
-        if (!/^_/.test(key) && typeof commander[key] === 'string') { // commander 自带了一批 _开头的属性，过滤掉
-          global.envar[key] = commander[key]
+        console.log('- Merging Command Line Parameters into Configuration (把命令行参数值合并入配置)')
+        for (let key in commander) {
+          if (!/^_/.test(key) && typeof commander[key] === 'string') { // commander 自带了一批 _开头的属性，过滤掉
+            global.envar[key] = commander[key]
+          }
         }
       }
     }
 
-    console.log('>>>>>>>> Collected Environment Configuration >>>>>>>>')
+    console.log('>>>>>>>> Configured Environment Variables >>>>>>>>')
     return global.envar
   },
 
-  getDynamicConfig(dynamicConfigFile='envar-base-dynamic.js') { // dynamicConfigFile should be absolute or relative to the node process's dir.
-    const fullpath = path.resolve(dynamicConfigFile)
+  getDynamicEnvar({dynamicEnvarFile='envar-base-dynamic.js'}={}) { // dynamicEnvarFile should be absolute or relative to the node process's dir.
+    const fullpath = path.resolve(dynamicEnvarFile)
     if (fs.existsSync(fullpath)) {
       delete require.cache[require.resolve(fullpath)] // delete require.cache[fullpath] 不起作用
       return require(fullpath)
@@ -61,11 +61,12 @@ module.exports = {
     }
   },
 
-  maskSecret() {
+  maskSecret({secretEnvarFile='./envar-base-secret.js'}={}) {
     let envar = JSON.parse(JSON.stringify(global.envar)) // 复制一份，避免污染
-    for (let key in envar) {
-      if (/^SECRET_/.test(key)) {
-        envar[key] = '*** confidentical ***'
+    if (fs.existsSync(path.resolve(secretEnvarFile))) {
+      const secretEnvar = require(path.resolve(secretEnvarFile))
+      for (let key in secretEnvar) {
+        envar[key] = '****** confidential ******'
       }
     }
     return envar