add rust examples

Author: tonytonyjan

examples/rust/README.txt

@@ -0,0 +1,3 @@
+This examples directory shows some examples written in Rust.
+
+You can also test the command files by running from the command line.

examples/rust/count.rs

@@ -0,0 +1,11 @@
+use std::io::{self, Write};
+use std::{thread, time};
+
+// Simple example script that counts to 10 at ~2Hz, then stops.
+fn main() {
+  for i in 1..11 {
+    println!("{}", i);
+    io::stdout().flush().ok().expect("Could not flush stdout");
+    thread::sleep(time::Duration::from_millis(500));
+  }
+}

examples/rust/dump-env.rs

@@ -0,0 +1,40 @@
+// Standard CGI(ish) environment variables, as defined in
+// http://tools.ietf.org/html/rfc3875
+
+use std::env;
+
+const NAMES: &'static [&'static str] = &[
+  "AUTH_TYPE",
+  "CONTENT_LENGTH",
+  "CONTENT_TYPE",
+  "GATEWAY_INTERFACE",
+  "PATH_INFO",
+  "PATH_TRANSLATED",
+  "QUERY_STRING",
+  "REMOTE_ADDR",
+  "REMOTE_HOST",
+  "REMOTE_IDENT",
+  "REMOTE_PORT",
+  "REMOTE_USER",
+  "REQUEST_METHOD",
+  "REQUEST_URI",
+  "SCRIPT_NAME",
+  "SERVER_NAME",
+  "SERVER_PORT",
+  "SERVER_PROTOCOL",
+  "SERVER_SOFTWARE",
+  "UNIQUE_ID",
+  "HTTPS",
+];
+
+fn main() {
+  for key in NAMES {
+    let value = env::var(key).unwrap_or(String::from("<unset>"));
+    println!("{}={}", key, value);
+  }
+  for (key, value) in env::vars() {
+    if key.starts_with("HTTP_") {
+      println!("{}={}", key, value);
+    }
+  }
+}

examples/rust/greeter.rs

@@ -0,0 +1,14 @@
+use std::io::{self, Write};
+
+// For each line FOO received on STDIN, respond with "Hello FOO!".
+fn main() {
+  loop {
+    let mut msg = String::new();
+    io::stdin()
+      .read_line(&mut msg)
+      .expect("Failed to read line");
+    let msg = msg.trim();
+    println!("Hello {}!", msg);
+    io::stdout().flush().ok().expect("Could not flush stdout");
+  }
+}