Add Gist Support

Cargo.toml

@@ -19,6 +19,7 @@ rustc-serialize = "0.3.16"
 shaman = "0.1.0"
 time = "0.1.25"
 toml = "0.1.20"
+curl = "0.2.18"
 
 [dependencies.clap]
 version = "1.4.5"

src/main.rs

@@ -19,6 +19,7 @@ As such, `cargo-script` does two major things:
 2. It caches the generated and compiled packages, regenerating them only if the script or its metadata have changed.
 */
 extern crate clap;
+extern crate curl;
 extern crate env_logger;
 #[macro_use] extern crate lazy_static;
 #[macro_use] extern crate log;
@@ -41,6 +42,7 @@ mod error;
 mod manifest;
 mod platform;
 mod util;
+mod web;
 
 use std::borrow::Cow;
 use std::error::Error;
@@ -107,7 +109,7 @@ fn parse_args() -> Args {
             Major script modes.
             */
             .arg(Arg::with_name("script")
-                .help("Script file (with or without extension) to execute.")
+                .help("Script file (with or without extension) or URL to execute.")
                 .index(1)
             )
             .arg(Arg::with_name("args")
@@ -311,21 +313,28 @@ fn try_main() -> Result<i32> {
 
     let input = match (args.script, args.expr, args.loop_) {
         (Some(script), false, false) => {
-            let (path, mut file) = try!(find_script(script).ok_or("could not find script"));
+            if script.starts_with("https://") || script.starts_with("http://") {
+                // If the script path contains the HTTP or HTTPS protocols, download and execute it as an expression.
+                content = web::download_script(&script).unwrap();
+                Input::Expr(&content)
+            } else {
+                // If the script does not define a protocol, it is a file on the local filesystem.
+                let (path, mut file) = try!(find_script(script).ok_or("could not find script"));
 
-            script_name = path.file_stem()
-                .map(|os| os.to_string_lossy().into_owned())
-                .unwrap_or("unknown".into());
+                script_name = path.file_stem()
+                    .map(|os| os.to_string_lossy().into_owned())
+                    .unwrap_or("unknown".into());
 
-            let mut body = String::new();
-            try!(file.read_to_string(&mut body));
+                let mut body = String::new();
+                try!(file.read_to_string(&mut body));
 
-            let mtime = platform::file_last_modified(&file);
+                let mtime = platform::file_last_modified(&file);
 
-            script_path = try!(std::env::current_dir()).join(path);
-            content = body;
+                script_path = try!(std::env::current_dir()).join(path);
+                content = body;
 
-            Input::File(&script_name, &script_path, &content, mtime)
+                Input::File(&script_name, &script_path, &content, mtime)
+            }
         },
         (Some(expr), true, false) => {
             content = expr;
@@ -1117,7 +1126,7 @@ impl<'a> Input<'a> {
 /**
 Shorthand for hashing a string.
 */
-fn hash_str(s: &str) -> String {
+fn hash_str(s: &str) ->  String {
     use shaman::digest::Digest;
     use shaman::sha1::Sha1;
     let mut hasher = Sha1::new();

src/web.rs

@@ -0,0 +1,52 @@
+extern crate curl;
+use curl::http;
+
+/// Obtains the raw URL for GitHub and Gist URLs
+fn generate_url(url: &str) -> Result<String, curl::ErrCode> {
+    let mut output = String::from(url);
+    if output.contains("gist.github.com") {
+        let content = match get_html_response(url) {
+            Ok(content) => content,
+            Err(message) => { return Err(message); }
+        };
+        output = get_raw_gist_url(&content).unwrap();
+    }
+    if output.starts_with("github.com") {
+        output = output.replace("github.com", "raw.githubusercontent.com");
+    }
+    Ok(output)
+}
+
+/// Obtains the raw Gist URL from the Gist HTML Body
+fn get_raw_gist_url(html: &str) -> Option<String> {
+    for line in html.lines() {
+        if line.contains("/raw/") {
+            let suffix = line.split("\"").nth(1).unwrap();
+            return Some(String::from("https://gist.githubusercontent.com") + suffix);
+        }
+    }
+    None
+}
+
+/// Returns the HTML body's response.
+fn get_html_response(url: &str) -> Result<String, curl::ErrCode> {
+    let response = match http::handle().get(url).exec() {
+        Ok(response) => response,
+        Err(message) => { return Err(message); }
+    };
+    Ok(String::from(match ::std::str::from_utf8(response.get_body()) {
+        Ok(reply) => reply,
+        Err(_) => { panic!("response is not a valid UTF8 string"); }
+    }).replace("fn main()", ""))
+}
+
+/// Opens a URL and returns the source code found at the address.
+pub fn download_script(url: &str) -> Result<String, curl::ErrCode> {
+    match generate_url(&url) {
+        Ok(url) => match get_html_response(&url) {
+            Ok(code) => Ok(code),
+            Err(message) => Err(message)
+        },
+        Err(message) => Err(message)
+    }
+}