Set dotenv_config_* vars via env var

README.md

@@ -65,6 +65,9 @@ The configuration options below are supported as command line arguments in the f
 $ node -r dotenv/config your_script.js dotenv_config_path=/custom/path/to/your/env/vars
 ```
 
+If you are having trouble passing the `dotenv_config_<option>=value` part via the CLI, you can use environment variables instead. When using environment variables, be sure to use uppercase names, `DOTENV_CONFIG_<OPTION>=value`. 
+
+
 ## Config
 
 _Alias: `load`_

config.js

@@ -2,6 +2,6 @@
 
 (function () {
   require('./lib/main').config(
-    require('./lib/cli-options')(process.argv)
+    Object.assign({}, require('./lib/env-options')(process.env), require('./lib/cli-options')(process.argv))
   )
 })()

lib/env-options.js

@@ -0,0 +1,9 @@
+/* @flow */
+
+module.exports = function (env = {}) {
+  return Object.assign({},
+    env.DOTENV_CONFIG_ENCODING ? { encoding: env.DOTENV_CONFIG_ENCODING } : null,
+    env.DOTENV_CONFIG_PATH ? { path: env.DOTENV_CONFIG_PATH } : null,
+    env.DOTENV_CONFIG_DEBUG ? { debug: env.DOTENV_CONFIG_DEBUG } : null
+  )
+}

tests/test-env-options.js

@@ -0,0 +1,29 @@
+/* @flow */
+
+const t = require('tap')
+
+const options = require('../lib/env-options')
+
+t.plan(6)
+
+// matches encoding option
+t.same(options({ DOTENV_CONFIG_ENCODING: 'utf8' }), {
+  encoding: 'utf8'
+})
+
+// matches path option
+t.same(options({ DOTENV_CONFIG_PATH: '/custom/path/to/your/env/vars' }), {
+  path: '/custom/path/to/your/env/vars'
+})
+
+// matches debug option
+t.same(options({ DOTENV_CONFIG_DEBUG: 'true' }), {
+  debug: 'true'
+})
+
+// ignores empty values
+t.same(options(), {})
+t.same(options({}), {})
+
+// ignores unsupported options
+t.same(options({ DOTENV_CONFIG_FOO: 'foo' }), {})