Added echo.go and updated waf script.

go/README

@@ -9,3 +9,13 @@ Installing waf
 $ curl -O http://waf.googlecode.com/files/waf-1.6.3
 $ mv waf-1.6.3 waf
 $ ./waf --version
+
+----------------------------
+
+This directory:
+
+$ ./waf configure
+
+$ ./waf build (or just ./waf)
+
+$ ./waf distclean

go/echo.go

@@ -0,0 +1,24 @@
+package main
+
+import ("os"
+        "flag")
+
+var omitNewLine = flag.Bool("n", false, "Omit new line")
+
+const (Space = " "; Newline = "\n")
+
+func main() {
+  flag.Parse()
+
+  var s string = "";
+
+  for i := 0; i < flag.NArg(); i++ {
+    if i > 0 { s += Space }
+
+    s += flag.Arg(i);
+  }
+
+  if !*omitNewLine { s += Newline }
+
+  os.Stdout.WriteString(s)
+}

go/wscript

@@ -8,9 +8,15 @@ def configure(ctx):
   ctx.env.GOC = "6g"
   ctx.env.GOL = "6l"
 
-def build(ctx):
+def go(ctx, source, target):
   go_compile = "${GOC} -o ${TGT} ${SRC}"
   go_link = "${GOL} -o ${TGT} ${SRC}"
 
-  ctx(rule=go_compile, source="hello.go", target="hello.6")
-  ctx(rule=go_link, source="hello.6", target="hello")
+  object_file = target + ".6"
+
+  ctx(rule=go_compile, source=source, target=object_file)
+  ctx(rule=go_link, source=object_file, target=target)
+
+def build(ctx):
+  go(ctx, "hello.go", "hello")
+  go(ctx, "echo.go", "echo")