Update to gobook@c6d7a22edd03e7738c38d5baa2174ff325d8d863

ch10/cross/main.go

@@ -0,0 +1,19 @@
+// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+
+// See page 295.
+
+// The cross command prints the values of GOOS and GOARCH for this target.
+package main
+
+import (
+	"fmt"
+	"runtime"
+)
+
+//!+
+func main() {
+	fmt.Println(runtime.GOOS, runtime.GOARCH)
+}
+
+//!-