Put version into CLI

Author: mitchellh

.gitignore

@@ -1,2 +1,4 @@
+dist/
+
 # For testing:
 config.hcl

Makefile

@@ -1,9 +1,11 @@
+VERSION := 0.1.0
+
 # Note that I'd love to use goreleaser for this but they don't quite
 # have the hooks yet to be able to merge in gon support. Ideally they'd
 # just integrate natively in some way.
 build: clean
 	mkdir -p dist
-	GOOS=darwin GOARCH=amd64 go build -o ./dist/gon ./cmd/gon
+	GOOS=darwin GOARCH=amd64 go build -ldflags "-X main.version=$(VERSION)" -o ./dist/gon ./cmd/gon
 .PHONY: build
 
 # release will package the distribution packages, sign, and notarize

cmd/gon/main.go

@@ -19,11 +19,29 @@ import (
 	"github.com/mitchellh/gon/sign"
 )
 
+// Set by build process
+var (
+	version string
+)
+
 func main() {
 	os.Exit(realMain())
 }
 
 func realMain() int {
+	// Look for version
+	for _, v := range os.Args[1:] {
+		v = strings.TrimLeft(v, "-")
+		if v == "v" || v == "version" {
+			if version == "" {
+				version = "dev"
+			}
+
+			fmt.Printf("version %s\n", version)
+			return 0
+		}
+	}
+
 	var logLevel string
 	var logJSON bool
 	flags := flag.NewFlagSet(os.Args[0], flag.ExitOnError)