urldump

README.md

urldump

This is a hexdump-style stream processing tool to convert from readable, UTF8-encoded text into URL-encoded output.

Install

sudo npm -g install git+https://gist.github.com/bc62904c1956837a01d49d11767f8102.git

Usage

$ echo '<script>alert(1)</script>' | urldump
%3c%73%63%72%69%70%74%3e%61%6c%65%72%74%28%31%29%3c%2f%73%63%72%69%70%74%3e%a

index.js

#!/usr/bin/env node

const STDIN_ENCODING = "utf8";

// Represents input received from stdin
class Stdin {
    constructor(encoding = STDIN_ENCODING) {
        this.close = () => null;
        process.stdin.setEncoding(encoding);
        process.stdin.on("end", () => this.close());
    }

    // Registers a callback to be invoked when data is read
    onRead(fn) {
        process.stdin.on("readable", () => {
            var chunk = process.stdin.read();
            if (chunk !== null) {
                fn(chunk);
            }
        });
    }

    // Registers a callback to be invoked when stdin closes
    onClose(fn) {
        this.close = fn.bind(this);
    }
}

// Converts a string to its url-encoded version
function urlEncodeString(string) {
    var urlEncodeChar = (chr) => "%" + chr.charCodeAt(0).toString(16);
    return [].map.call(string, urlEncodeChar).join("");
}

(function main() {
    var stdin = new Stdin();
    stdin.onClose(() => {
        process.stdout.write("\n");
        process.exit.bind(0);
    });
    stdin.onRead((d) => process.stdout.write(urlEncodeString(d)));
})();

package.json

{
  "name": "urldump",
  "version": "0.1.0",
  "description": "convert between URL encoding and UTF-8",
  "main": "index.js",
  "bin": "./index.js",
  "author": "",
  "license": "MIT"
}