1. Overall Requirement

You will write two programs that exercise a simplified version of HTTP. The retriever will work in conjunction with any web server and the server will work in conjunction with any web browser. This way, you can test your software independently of each other.

You need to write C++ implement the retriever and server.

You should not use existing libraries to retrieve HTTP files or perform socket communication.

You need to write both the build script and demo script files using bash shell script.

2. Detailed Requirement

Retriever

Your retriever takes in an input from the command line and parses the server address and file (web page) that is being requested.

The program then issues a GET request to the server for the requested file.

When the file is returned by the server, the retriever outputs the file to the screen and saves the retrieved file to the file system.

If the server returns an error code instead of an OK code, then the retriever should not save the file and should display on the screen whatever error page was sent with the error.

Your retriever should exit after receiving the response.

The server name can be either an IP address for simplicity.

Server

Your server waits for a connection and an HTTP GET request (Please perform multi-threaded handling).

Your server only needs to respond to HTTP GET request.

After receiving the GET request

If the file exists, the server opens the file that is requested and sends it (along with the HTTP 200 OK code, of course).

If the file requested does not exist, the server should return a 404 Not Found code along with a custom File Not Found page.

If the HTTP request is for SecretFile.html then the web server should return a 401 Unauthorized.

If the request is for a file that is above the directory structure where your web server is running ( for example, "GET ../../../etc/passwd" ), you should return a 403 Forbidden.

Finally, if your server cannot understand the request, return a 400 Bad Request.

After you handle the request, your server should return to waiting for the next request.