cmd: add a `disasm --no-stdout` flag

Since sometimes you just need to > /dev/null

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

cmd/tar-split/disasm.go

@@ -3,6 +3,7 @@ package main
 import (
 	"compress/gzip"
 	"io"
+	"io/ioutil"
 	"os"
 
 	"github.com/Sirupsen/logrus"
@@ -48,7 +49,13 @@ func CommandDisasm(c *cli.Context) {
 	if err != nil {
 		logrus.Fatal(err)
 	}
-	i, err := io.Copy(os.Stdout, its)
+	var out io.Writer
+	if c.Bool("no-stdout") {
+		out = ioutil.Discard
+	} else {
+		out = os.Stdout
+	}
+	i, err := io.Copy(out, its)
 	if err != nil {
 		logrus.Fatal(err)
 	}

cmd/tar-split/main.go

@@ -42,6 +42,10 @@ func main() {
 					Value: "tar-data.json.gz",
 					Usage: "output of disassembled tar stream",
 				},
+				cli.BoolFlag{
+					Name:  "no-stdout",
+					Usage: "do not throughput the stream to STDOUT",
+				},
 			},
 		},
 		{