cmd/netstring/main.go | 24 ++++++++++++++----------

diff --git a/cmd/netstring/main.go b/cmd/netstring/main.go
index 33f35d4e0863d8db2ad0dbd0d83348b19202d5d1a29f1da0ded248bdd8434aa3..e01f3a1a1f36df386f7510a6fc2c9f2c8aeb41451aac1f304437cc0b2e353be4 100644
--- a/cmd/netstring/main.go
+++ b/cmd/netstring/main.go
@@ -32,7 +32,19 @@ 	fmt.Fprintf(os.Stderr, "ns -- Work with netstring encoded files\n\n")
 	fmt.Fprintf(os.Stderr, "Usage: %s list FILE\n", os.Args[0])
 	fmt.Fprintf(os.Stderr, "       %s read FILE CHUNK > data\n", os.Args[0])
 	fmt.Fprintf(os.Stderr, "       %s write FILE ... > data\n", os.Args[0])
+	fmt.Fprintf(os.Stderr, "FILE can be \"-\" for reading from stdin\n")
 	os.Exit(1)
+}
+
+func fileRead(path string) io.Reader {
+	if path == "-" {
+		return os.Stdin
+	}
+	fd, err := os.Open(path)
+	if err != nil {
+		panic(err)
+	}
+	return fd
 }
 
 func main() {
@@ -43,11 +55,7 @@ 		usage()
 	}
 	switch os.Args[1] {
 	case "list":
-		fd, err := os.Open(os.Args[2])
-		if err != nil {
-			panic(err)
-		}
-		r := netstring.NewReader(fd)
+		r := netstring.NewReader(fileRead(os.Args[2]))
 		for i := 0; ; i++ {
 			size, err := r.Next()
 			if err == io.EOF {
@@ -67,11 +75,7 @@ 		chunk, err := strconv.Atoi(os.Args[3])
 		if err != nil {
 			panic(err)
 		}
-		fd, err := os.Open(os.Args[2])
-		if err != nil {
-			panic(err)
-		}
-		r := netstring.NewReader(fd)
+		r := netstring.NewReader(fileRead(os.Args[2]))
 		for i := 0; i < chunk; i++ {
 			_, err = r.Next()
 			if err != nil {