rewrite snappytool in go

cmd/snappytool/main.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/golang/snappy"
+)
+
+var (
+	enc = flag.Bool("e", false, "encode")
+	dec = flag.Bool("d", false, "decode")
+)
+
+func run() int {
+	flag.Parse()
+	if *enc == *dec {
+		fmt.Fprintf(os.Stderr, "exactly one of -d or -e must be given")
+		return 1
+	}
+
+	// Encode or decode stdin, and write to stdout.
+	var err error
+	if *enc {
+		_, err = io.Copy(snappy.NewWriter(os.Stdout), os.Stdin)
+	} else {
+		_, err = io.Copy(os.Stdout, snappy.NewReader(os.Stdin))
+	}
+	if err != nil {
+		fmt.Fprintf(os.Stderr, err.Error())
+		return 1
+	}
+	return 0
+}
+
+func main() {
+	os.Exit(run())
+}