diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..551c545
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,6 @@
+all:
+	go run log4jscanner.go
+
+build:
+	go build -o log4jscanner
+
diff --git a/jar/backup.go b/jar/backup.go
new file mode 100644
index 0000000..fc27497
--- /dev/null
+++ b/jar/backup.go
@@ -0,0 +1,52 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jar
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"log"
+	"os"
+)
+
+func CreateDirectoryifNotExist(dir string) {
+	if _, err := os.Stat(dir); os.IsNotExist(err) {
+		err = os.Mkdir(dir, 0755)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+}
+
+func Backup(dstFileName string, srcFileName string) (written int64, err error) {
+	srcFile, err := os.Open(srcFileName)
+	if err != nil {
+		fmt.Printf("open file error = %v\n", err)
+	}
+	defer srcFile.Close()
+
+	reader := bufio.NewReader(srcFile)
+
+	dstFile, err := os.OpenFile(dstFileName, os.O_WRONLY|os.O_CREATE, 0666)
+	if err != nil {
+		fmt.Printf("open file error = %v\n", err)
+	}
+
+	writer := bufio.NewWriter(dstFile)
+
+	defer dstFile.Close()
+	return io.Copy(writer, reader)
+}
diff --git a/log4jscanner.go b/log4jscanner.go
index fdad047..0f979d3 100644
--- a/log4jscanner.go
+++ b/log4jscanner.go
@@ -40,6 +40,7 @@ Flags:
     -f, --force    Don't skip network and userland filesystems. (smb,nfs,afs,fuse)
     -w, --rewrite  Rewrite vulnerable JARs as they are detected.
     -v, --verbose  Print verbose logs to stderr.
+    -b, --backup   Suffix to use to backup a file when rewriting (.bak)
 
 `)
 }
@@ -74,8 +75,10 @@ func main() {
 	flag.BoolVar(&w, "w", false, "")
 	flag.BoolVar(&verbose, "verbose", false, "")
 	flag.BoolVar(&v, "v", false, "")
+  
 	flag.BoolVar(&force, "force", false, "")
 	flag.BoolVar(&f, "f", false, "")
+
 	flag.Func("s", "", appendSkip)
 	flag.Func("skip", "", appendSkip)
 	flag.Usage = usage
@@ -94,10 +97,12 @@ func main() {
 	if w {
 		rewrite = w
 	}
+
 	log.SetFlags(log.LstdFlags | log.Lshortfile)
 	logf := func(format string, v ...interface{}) {
 		if verbose {
 			log.Printf(format, v...)
+
 		}
 	}
 	seen := 0
@@ -140,6 +145,7 @@ func main() {
 		},
 	}
 
+  
 	for _, dir := range dirs {
 		logf("Scanning %s", dir)
 		if err := walker.Walk(dir); err != nil {