How to accept and read data from httpcontext in php?

Question

I want to add a page written in PHP to handle HTTP Requests, and to answer them. All I want is a page that does like below code:

    <%@ WebHandler Language="C#" Class="Handler" %> 
using System;
using System.Web; 
public class Handler : IHttpHandler {    
    public void ProcessRequest (HttpContext context) {
        //context.Response.read
        context.Response.ContentType = "text/plain";
        //context.Response.Write("Hello World");
        byte[] x = context.Request.BinaryRead(context.Request.ContentLength);

        context.Response.Write("Your message will be read soon!");
    } 
    public bool IsReusable 
    {
        get {
            return false;
        }
    }
}