Add version subcommand using embedded VCS info

Author: micthiesen

cmd/shellshape/main.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"fmt"
 	"os"
+	"runtime/debug"
 	"strings"
 
 	shellshape "github.com/micthiesen/shellshape"
@@ -12,6 +13,10 @@ import (
 
 func main() {
 	if len(os.Args) > 1 {
+		if os.Args[1] == "version" {
+			fmt.Println(versionString())
+			return
+		}
 		if os.Args[1] == "list" {
 			for _, name := range shellshape.RegisteredHandlers() {
 				fmt.Println(name)
@@ -46,3 +51,34 @@ func main() {
 		os.Exit(1)
 	}
 }
+
+func versionString() string {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return "shellshape (unknown)"
+	}
+	var revision, time string
+	var dirty bool
+	for _, s := range info.Settings {
+		switch s.Key {
+		case "vcs.revision":
+			revision = s.Value
+		case "vcs.time":
+			time = s.Value
+		case "vcs.modified":
+			dirty = s.Value == "true"
+		}
+	}
+	if revision == "" {
+		return "shellshape (dev)"
+	}
+	short := revision
+	if len(short) > 7 {
+		short = short[:7]
+	}
+	v := "shellshape " + short + " (" + time + ")"
+	if dirty {
+		v += " dirty"
+	}
+	return v
+}

handlers/shellshape.go

@@ -13,9 +13,9 @@ func init() {
 func handleShellshape(subcommand string, tokens []string) []string {
 	args, redirects := shellshape.SplitRedirects(tokens)
 
-	// "list" subcommand has no args to normalize.
-	if len(args) > 0 && args[0] == "list" {
-		return append([]string{"list"}, redirects...)
+	// Subcommands with no args to normalize.
+	if len(args) > 0 && (args[0] == "list" || args[0] == "version") {
+		return append([]string{args[0]}, redirects...)
 	}
 
 	var result []string

handlers/shellshape_test.go

@@ -21,8 +21,9 @@ func TestShellshape(t *testing.T) {
 		{"command with pipes as single arg", `shellshape 'echo hello | grep h'`, "shellshape <command>"},
 		{"multiple words", "shellshape docker run -it ubuntu bash", "shellshape <command>"},
 
-		// List subcommand
+		// Subcommands
 		{"list subcommand", "shellshape list", "shellshape list"},
+		{"version subcommand", "shellshape version", "shellshape version"},
 
 		// With redirect
 		{"with redirect", "shellshape echo hi > /tmp/out.txt", "shellshape <command> > <path>"},