Update version management

txeh/cmd/root.go

@@ -17,7 +17,7 @@ var rootCmd = &cobra.Command{
 | |___  _____| |__
 | __\ \/ / _ \ '_ \
 | |_ >  <  __/ | | |
- \__/_/\_\___|_| |_| v` + Version + `
+ \__/_/\_\___|_| |_| Version: ` + VersionFromBuild() + `
 
 Add, remove and re-associate hostname entries in your /etc/hosts file.
 Read more including usage as a Go library at https://github.com/txn2/txeh`,

txeh/cmd/version.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"fmt"
+	"runtime/debug"
 
 	"github.com/spf13/cobra"
 )
@@ -17,6 +18,26 @@ var versionCmd = &cobra.Command{
 	Short: "Print the version number of txeh",
 	Long:  ``,
 	Run: func(cmd *cobra.Command, args []string) {
-		fmt.Printf("txeh Version %s\n", Version)
+		version := VersionFromBuild()
+		fmt.Printf("txeh Version: %s\n", version)
 	},
 }
+
+// Version returns the version of txeh binary
+func VersionFromBuild() (version string) {
+	// Version is managed with goreleaser
+	if Version != "0.0.0" {
+		return Version
+	}
+	// Version is managed by "go install"
+	b, ok := debug.ReadBuildInfo()
+	if !ok {
+		return "unknown"
+	}
+	if b == nil {
+		version = "nil"
+	} else {
+		version = b.Main.Version
+	}
+	return version
+}