Adds version information to builds; fixes #19

Author: tomnomnom

CHANGELOG.mkd

@@ -1,8 +1,9 @@
 # Changelog
 
-## HEAD
+## 0.3.3
 - Slightly improved error reporting when ungronning
 - 20 second timeout on HTTP(s) requests (thanks @gummiboll!)
+- Version information added at build time + `--version` option (issue #19)
 
 ## 0.3.2
 - Adds handling of `--` lines produced by grep -A etc (issue #15)

README.mkd

@@ -183,6 +183,7 @@ Usage:
 Options:
   -u, --ungron     Reverse the operation (turn assignments back into JSON)
   -m, --monochrome Monochrome (don't colorize output)
+      --version    Print version information
 
 Exit Codes:
   0 OK

main.go

@@ -15,6 +15,7 @@ import (
 	"github.com/pkg/errors"
 )
 
+// Exit codes
 const (
 	exitOK = iota
 	exitOpenFile
@@ -25,6 +26,7 @@ const (
 	exitJSONEncode
 )
 
+// Output colors
 var (
 	strColor   = color.New(color.FgYellow)
 	braceColor = color.New(color.FgMagenta)
@@ -33,6 +35,10 @@ var (
 	boolColor  = color.New(color.FgCyan)
 )
 
+// gronVersion stores the current gron version, set at build
+// time with the ldflags -X option
+var gronVersion = "dev"
+
 func init() {
 	flag.Usage = func() {
 		h := "Transform JSON (from a file, URL, or stdin) into discrete assignments to make it greppable\n\n"
@@ -42,7 +48,8 @@ func init() {
 
 		h += "Options:\n"
 		h += "  -u, --ungron     Reverse the operation (turn assignments back into JSON)\n"
-		h += "  -m, --monochrome Monochrome (don't colorize output)\n\n"
+		h += "  -m, --monochrome Monochrome (don't colorize output)\n"
+		h += "      --version    Print version information\n\n"
 
 		h += "Exit Codes:\n"
 		h += fmt.Sprintf("  %d\t%s\n", exitOK, "OK")
@@ -68,15 +75,23 @@ func main() {
 	var (
 		ungronFlag     bool
 		monochromeFlag bool
+		versionFlag    bool
 	)
 
 	flag.BoolVar(&ungronFlag, "ungron", false, "Turn statements into JSON instead")
 	flag.BoolVar(&ungronFlag, "u", false, "Turn statements into JSON instead")
 	flag.BoolVar(&monochromeFlag, "monochrome", false, "Monochrome (don't colorize output)")
 	flag.BoolVar(&monochromeFlag, "m", false, "Monochrome (don't colorize output)")
+	flag.BoolVar(&versionFlag, "version", false, "Print version information")
 
 	flag.Parse()
 
+	// Print version information
+	if versionFlag {
+		fmt.Printf("gron version %s\n", gronVersion)
+		os.Exit(exitOK)
+	}
+
 	var raw io.Reader
 
 	filename := flag.Arg(0)

script/release

@@ -52,7 +52,7 @@ for ARCH in "amd64" "386"; do
 
         rm -f ${BINFILE}
 
-        GOOS=${OS} GOARCH=${ARCH} go build github.com/${USER}/${REPO}
+        GOOS=${OS} GOARCH=${ARCH} go build -ldflags "-X main.gronVersion=${VERSION}" github.com/${USER}/${REPO}
 
         if [[ "${OS}" == "windows" ]]; then
             ARCHIVE="${BINARY}-${OS}-${ARCH}-${VERSION}.zip"

url.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bufio"
+	"fmt"
 	"io"
 	"net/http"
 	"strings"
@@ -21,7 +22,7 @@ func getURL(url string) (io.Reader, error) {
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("User-Agent", "gron/0.2")
+	req.Header.Set("User-Agent", fmt.Sprintf("gron/%s", gronVersion))
 	req.Header.Set("Accept", "application/json")
 
 	resp, err := client.Do(req)