Split out cli code and add version flag

Makefile

@@ -0,0 +1,2 @@
+all:
+	@go build -ldflags "-X main.buildTime=`date -u '+%Y-%m-%d_%I:%M:%S%p'` -X main.buildRev=`git rev-parse --short HEAD` -X main.buildTag=`git describe --tags --long`"

main.go

@@ -0,0 +1,87 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+)
+
+// TODO allow custom log location
+const logloc string = "/tmp/porcelain.log"
+
+var (
+	buildRev  string = "invalid"
+	buildTag  string = "invalid"
+	buildTime string = "invalid"
+)
+
+var (
+	cwd                     string
+	noColorFlag             bool
+	debugFlag, fmtFlag      bool
+	bashFmtFlag, zshFmtFlag bool
+	tmuxFmtFlag             bool
+	versionFlag             bool
+)
+
+func init() {
+	flag.BoolVar(&debugFlag, "debug", false, "write logs to file ("+logloc+")")
+	flag.BoolVar(&fmtFlag, "fmt", true, "print formatted output (default)")
+	flag.BoolVar(&bashFmtFlag, "bash", false, "escape fmt output for bash")
+	flag.BoolVar(&noColorFlag, "no-color", false, "print formatted output without color codes")
+	flag.BoolVar(&zshFmtFlag, "zsh", false, "escape fmt output for zsh")
+	flag.BoolVar(&tmuxFmtFlag, "tmux", false, "escape fmt output for tmux")
+	flag.StringVar(&cwd, "path", "", "show output for path instead of the working directory")
+	flag.BoolVar(&versionFlag, "version", false, "print version and exit")
+
+	logtostderr := flag.Bool("logtostderr", false, "write logs to stderr")
+	flag.Parse()
+
+	if versionFlag {
+		fmt.Printf("porcelain version %s (%s)\nbuilt %s\n", buildTag, buildRev, buildTime)
+		os.Exit(0)
+	}
+
+	if debugFlag {
+		var (
+			err   error
+			logFd io.Writer
+		)
+		if *logtostderr {
+			logFd = os.Stderr
+		} else {
+			logFd, err = os.OpenFile(logloc, os.O_CREATE|os.O_RDWR|os.O_APPEND, os.ModePerm)
+			if err != nil {
+				os.Exit(1)
+			}
+		}
+		log.SetOutput(logFd)
+		log.SetFlags(log.Ldate | log.Ltime | log.Llongfile)
+	} else {
+		log.SetOutput(ioutil.Discard)
+	}
+
+	if cwd == "" {
+		cwd, _ = os.Getwd()
+	}
+}
+
+func main() {
+	log.Println("running porcelain...")
+	log.Println("in directory:", cwd)
+
+	var out string
+	switch {
+	case fmtFlag:
+		out = run().Fmt()
+	default:
+		flag.Usage()
+		fmt.Println("\nOutside of a repository there will be no output.")
+		os.Exit(1)
+	}
+
+	fmt.Fprint(os.Stdout, out)
+}

porcelain.go

@@ -2,9 +2,7 @@ package main
 
 import (
 	"bytes"
-	"flag"
 	"fmt"
-	"io"
 	"io/ioutil"
 	"log"
 	"os"
@@ -13,17 +11,6 @@ import (
 	"github.com/robertgzr/color"
 )
 
-// TODO allow custom log location
-const logloc string = "/tmp/porcelain.log"
-
-var (
-	cwd                     string
-	noColorFlag             bool
-	debugFlag, fmtFlag      bool
-	bashFmtFlag, zshFmtFlag bool
-	tmuxFmtFlag             bool
-)
-
 type GitArea struct {
 	modified int
 	added    int
@@ -212,56 +199,3 @@ func run() *PorcInfo {
 
 	return porcInfo
 }
-
-func init() {
-	flag.BoolVar(&debugFlag, "debug", false, "write logs to file ("+logloc+")")
-	flag.BoolVar(&fmtFlag, "fmt", true, "print formatted output (default)")
-	flag.BoolVar(&bashFmtFlag, "bash", false, "escape fmt output for bash")
-	flag.BoolVar(&noColorFlag, "no-color", false, "print formatted output without color codes")
-	flag.BoolVar(&zshFmtFlag, "zsh", false, "escape fmt output for zsh")
-	flag.BoolVar(&tmuxFmtFlag, "tmux", false, "escape fmt output for tmux")
-	flag.StringVar(&cwd, "path", "", "show output for path instead of the working directory")
-
-	logtostderr := flag.Bool("logtostderr", false, "write logs to stderr")
-	flag.Parse()
-
-	if debugFlag {
-		var (
-			err   error
-			logFd io.Writer
-		)
-		if *logtostderr {
-			logFd = os.Stderr
-		} else {
-			logFd, err = os.OpenFile(logloc, os.O_CREATE|os.O_RDWR|os.O_APPEND, os.ModePerm)
-			if err != nil {
-				os.Exit(1)
-			}
-		}
-		log.SetOutput(logFd)
-		log.SetFlags(log.Ldate | log.Ltime | log.Llongfile)
-	} else {
-		log.SetOutput(ioutil.Discard)
-	}
-
-	if cwd == "" {
-		cwd, _ = os.Getwd()
-	}
-}
-
-func main() {
-	log.Println("running porcelain...")
-	log.Println("in directory:", cwd)
-
-	var out string
-	switch {
-	case fmtFlag:
-		out = run().Fmt()
-	default:
-		flag.Usage()
-		fmt.Println("\nOutside of a repository there will be no output.")
-		os.Exit(1)
-	}
-
-	fmt.Fprint(os.Stdout, out)
-}