curl.ts example with reference in manual (#3161)

std/examples/README.md

@@ -37,6 +37,12 @@ catj file1.json file2.json
 echo example.json | catj -
 ```
 
+### curl - print the contents of a url to standard output
+
+```shell
+deno --allow-net=deno.land https://deno.land/std/examples/curl.ts https://deno.land/
+```
+
 ### gist - easily create and upload Gists
 
 ```

std/examples/curl.ts

@@ -0,0 +1,8 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+async function curl(url: string): Promise<void> {
+  const res = await fetch(url);
+  await Deno.copy(Deno.stdout, res.body);
+}
+
+await curl(Deno.args[1]);
+Deno.exit(0);

website/manual.md

@@ -421,11 +421,11 @@ $ deno --allow-read=/etc https://deno.land/std/examples/cat.ts /etc/passwd
 This is an example to restrict host.
 
 ```ts
-const result = await fetch("https://deno.land/std/examples/echo_server.ts");
+const result = await fetch("https://deno.land/");
 ```
 
 ```shell
-$ deno --allow-net=deno.land allow-net-whitelist-example.ts
+$ deno --allow-net=deno.land https://deno.land/std/examples/curl.ts https://deno.land/
 ```
 
 ### Run subprocess