From 8dd29d34bf0186945d53ba1ca0cde2324952a6e9 Mon Sep 17 00:00:00 2001
From: brettlangdon <me@brett.is>
Date: Mon, 18 Jan 2016 13:42:04 -0500
Subject: Add support for environment variables

---
 README.md | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

(limited to 'README.md')

diff --git a/README.md b/README.md
index f4c8d11..3d1d12f 100644
--- a/README.md
+++ b/README.md
@@ -54,6 +54,41 @@ Input: src.txt
 Output: [x.out y.out z.out]
 ```
 
+### Environment variables
+
+```go
+var args struct {
+	Workers int `arg:"env"`
+}
+arg.MustParse(&args)
+fmt.Println("Workers:", args.Workers)
+```
+
+```
+$ WORKERS=4 ./example
+Workers: 4
+```
+
+```
+$ WORKERS=4 ./example --workers=6
+Workers: 6
+```
+
+You can also override the name of the environment variable:
+
+```go
+var args struct {
+	Workers int `arg:"env:NUM_WORKERS"`
+}
+arg.MustParse(&args)
+fmt.Println("Workers:", args.Workers)
+```
+
+```
+$ NUM_WORKERS=4 ./example
+Workers: 4
+```
+
 ### Usage strings
 ```go
 var args struct {
-- 
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