Rocket/examples/raw_upload/src/main.rs

#![feature(plugin)]
#![plugin(rocket_codegen)]

extern crate rocket;

use std::io;

use rocket::request::Data;
use rocket::response::data::Plain;

#[post("/upload", format = "text/plain", data = "<data>")]
fn upload(data: Data) -> io::Result<Plain<String>> {
    data.stream_to_file("/tmp/upload.txt").map(|n| Plain(n.to_string()))
}

#[get("/")]
fn index() -> &'static str {
    "Upload your text files by POSTing them to /upload."
}

fn main() {
    rocket::ignite().mount("/", routes![index, upload]).launch();
}