feat: add go version, commit hash and build time to the version info

and pass all these via the compile time variable definition
(ldflags)

Author: JayceChant

Makefile

@@ -1,12 +1,12 @@
-APPNAME = commit-msg
+APPNAME := commit-msg
 LDFLAGS += -s -w
 
 .PHONY: all build upx
 
 all: build upx
 
 build:
-	go build -trimpath -ldflags '$(LDFLAGS)'
+	go build -trimpath -ldflags "$(LDFLAGS) -X 'main.version=$(TAG)' -X 'main.goVersion=$(shell go version)' -X 'main.commitHash=$(shell git show -s --format=%H)' -X 'main.buildTime=$(shell date "+%Y-%m-%d %T%z")'"
 
 upx:
 	upx `find -maxdepth 1 -name "$(APPNAME)" -o -name "$(APPNAME).exe"`

main.go

@@ -9,12 +9,12 @@ import (
 	"github.com/JayceChant/commit-msg/validator"
 )
 
-const (
-	versionStr = "v0.2.0"
-)
-
 var (
 	versionFlag = flag.Bool("version", false, "")
+	version     string
+	goVersion   string
+	commitHash  string
+	buildTime   string
 )
 
 func main() {
@@ -33,5 +33,14 @@ func main() {
 }
 
 func printVersion(cmd string) {
-	fmt.Printf("%s %s\n", filepath.Base(cmd), versionStr)
+	fmt.Println(filepath.Base(cmd), version)
+	if goVersion != "" {
+		fmt.Println(goVersion)
+	}
+	if commitHash != "" {
+		fmt.Println("commit hash :", commitHash)
+	}
+	if buildTime != "" {
+		fmt.Println("build at :", buildTime)
+	}
 }