httpd

HTTPD Lab

In this lab you will implement a fairly complete httpd. You will need to have the netscape browser connect to your httpd and will be able to transfer files across the network.

This tutorial should help you in getting your httpd working. You might also want to look at some cgi documentation.

You will probably want to fork off a child or thread to handle each http session. This will allow several clients to access files at the same time.

You can test using the following files:

You should be able to access them by putting a url that looks something like

http://flute.cs.byu.edu:1236/students/cs460ta/public_html/test1.html

In this example I am running the server on flute at port 1236 and am trying to access the file in the directory /students/cs460ta/public_html/test1.html. You can put the files in any location, but you must be able to access them from a normal browser (netscape or ie). If the file does not exist, or if you get any other error, you should construct an appropriate error page and send it back. If the file is a directory, you should first look to see if there is an index.html file in the directory. If so, you send it back, if not, you should produce a listing of the files in the directory, format it with a html header and trailer and then send that page back to the browser.

YOUR HTTPD SHOULD ALSO BE ABLE TO SHOW A DIRECTORY LISTING!

This simple cgi file can be used to test your cgi functionality. You will have to save it away as test5.cgi and execute it when it is accessed. It simply produces a html file that you then send to the browser. Before sending the file to the browser, you need to send the
```
"HTTP/1.0 200 OK\r\n"
"MIME-Version:1.0\r\n"
```
strings. The CGI script will send the content type and everything else. You can access it with a url that looks something like the following. If you put it in your cgi-bin directory, then you can test it with the normal web server for "students" to see what the output should be.

http://flute.cs.byu.edu:1236/students/cs460ta/public_html/cgi-bin/test5.cgi

This more complicated cgi file must be passed arguments. You will have to save it away as test6.cgi and execute it when it is accessed. In order to pass off this part of the lab, you will have to set up the environment variables correctly. You will only have to implement the GET request method. It simply produces a html file that you then send to the browser. You can access it with a url that looks something like the following. If you put it in your cgi-bin directory, then you can test it with the normal web server for "students" to see what the output should be. The teststring should appear in the QUERY_STRING in the environment and the REQUEST_METHOD and SERVER_PORT should also be correct. If this were a POST request, then the CONTENT_LENGTH would contain the length of the data being sent through stdin to the script. You might want to take a look at implementing the POST method if you are ambitious. You would normally do this from a form, not by just modifying the url in your browser.

http://flute.cs.byu.edu:1236/students/cs460ta/public_html/cgi-bin/test6.cgi?teststring

The following passoff levels will apply to this lab:

Passoff Level	Behavior	Points
Minimal Passoff	You can send the basic html, txt, gif, jpg files	4 Points
Basic CGI	You can run test5.cgi	3 Points
Perfect behavior	You can also pass environment variables to test6.cgi and list the contents of a directory if specified	3 Points