Ability to read from stdin

diff --git a/cmd/netstring/main.go b/cmd/netstring/main.go
index 306f46ebbfe0bdc879341de27df1d281ec9f3e53..460341e43cff5401eb1980d75f6e2766ebd9dc52 100644 (file)
--- a/cmd/netstring/main.go
+++ b/cmd/netstring/main.go
@@ -32,9 +32,21 @@ func usage() {
        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() {
        flag.Usage = usage
        flag.Parse()
@@ -43,11 +55,7 @@ func main() {
        }
        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 @@ func main() {
                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 {