diff --git a/README.md b/README.md
index 5a7fa9c..87c4d37 100644
--- a/README.md
+++ b/README.md
@@ -6,9 +6,10 @@ A kitchen sink of Go tools that I've found useful. Uses only the standard librar
 
 - [super lightweight http server framework](web)
 - [exponential backoff retry](retry.go)
-- [working with json](json.go)
+- [working with JSON](json.go)
 - [working with the file system](fs.go)
 - [working with slices](slice.go)
+- [working with CLIs](cli.go)
 
 ### example usage
 
diff --git a/app b/app
index 742a813..a658b53 100644
Binary files a/app and b/app differ
diff --git a/cli.go b/cli.go
index 2b715df..ec2b8da 100644
--- a/cli.go
+++ b/cli.go
@@ -2,9 +2,20 @@ package gotoolbox
 
 import (
 	"bytes"
+	"os"
 	"os/exec"
 )
 
+//GetEnvWithDefault returns the value of an enviornment variable
+//or a default value if the environment variables is not set
+func GetEnvWithDefault(key, defaultValue string) string {
+	result := os.Getenv(key)
+	if result == "" {
+		return defaultValue
+	}
+	return result
+}
+
 //ExecCmd executes a command and waits
 func ExecCmd(cmd *exec.Cmd) error {