add --version flag

Author: licong

.github/workflows/release.yml

@@ -14,7 +14,12 @@ jobs:
         stable: 'true'
         go-version: '^1.16.1'
     - name: build
-      run: go get github.com/mitchellh/gox  && mkdir dist && perl build.pl && ls -al dist/
+      run: |
+        export PATH=$PATH:$(go env GOPATH)/bin
+        go get github.com/mitchellh/gox
+        mkdir dist
+        perl build.pl
+        ls -al dist/
     - name: Upload binaries to release
       uses: svenstaro/upload-release-action@v2
       with:
@@ -24,4 +29,4 @@ jobs:
         asset_name: mything
         tag: ${{ github.ref }}
         overwrite: true
-        file_glob: true
+        file_glob: true

.gitignore

@@ -1 +1,2 @@
-*.exe
+*.exe
+with-env

main.go

@@ -1,17 +1,32 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime/debug"
 
 	"github.com/joho/godotenv"
 )
 
+var (
+	showVersion = flag.Bool("version", false, "pring progream version")
+)
+
 // first load env from ~/.env
 // second load env from .env
 func init() {
+	flag.Parse()
+	if *showVersion {
+		PrintVersion()
+		os.Exit(0)
+	}
+	if len(os.Args) < 2 {
+		fmt.Printf("Usage: with-env {command}\n")
+		os.Exit(1)
+	}
 	home, _ := os.UserHomeDir()
 	loadEnv(filepath.Join(home, ".env"), ".env")
 }
@@ -33,3 +48,10 @@ func main() {
 		os.Exit(1)
 	}
 }
+
+func PrintVersion() {
+	info, ok := debug.ReadBuildInfo()
+	if ok {
+		println(info.Main.Version, info.Main.Sum)
+	}
+}