add pretty print to json outputs

weed-fs/src/cmd/weed/weed.go

@@ -5,11 +5,11 @@ import (
 	"flag"
 	"fmt"
 	"io"
+	"math/rand"
 	"net/http"
 	"os"
 	"strings"
 	"sync"
-  "math/rand"
 	"text/template"
 	"time"
 	"unicode"
@@ -173,7 +173,12 @@ func exitIfErrors() {
 }
 func writeJson(w http.ResponseWriter, r *http.Request, obj interface{}) {
 	w.Header().Set("Content-Type", "application/javascript")
-	bytes, _ := json.Marshal(obj)
+	var bytes []byte
+	if r.FormValue("pretty") != "" {
+    bytes, _ = json.MarshalIndent(obj, "", "  ")
+	} else {
+    bytes, _ = json.Marshal(obj)
+	}
 	callback := r.FormValue("callback")
 	if callback == "" {
 		w.Write(bytes)