Description
Objective
The objective of this part of the homework is to develop 1 C++ program to:
• Develop a custom web-server how the bash shell runs commands
• Recollect the use of HTTP protocol for communication from prior projects
• Develop a web-server that can process HTTP GET requests
o Chunk data from a given file
o Run a program with command-line arguments and return its outputs
back to the client
o Work with anonymous pipes
• Continue to gain familiarity with I/O streams & string processing
• Learn functional testing of programs
• Do not use global variables
Submission Instructions
This homework assignment must be turned-in electronically via the CODE Canvas plug-in. First
ensure your program compiles without any warnings or style violations. Ensure you have tested
operations of your program as indicated. Once you have tested your implementation, upload just
your updated source file (named with convention MUID_hw5.cpp) and screenshot as required.
General Note: Upload each file associated with homework (or lab exercises) individually to
Canvas. Do not upload archive file formats such as zip/tar/gz/7zip/rar etc.
Grading Rubric:
The programs submitted for this homework must pass necessary base case
test(s) in order to qualify for earning any score at all. Programs that do not
meet base case requirements will be assigned zero score!
Program that do not compile, have a method longer than 25 lines or badly
formatted code as in } } }, etc., or just some skeleton code will be assigned
zero score.
• Point distribution for various commands:
o Base case: Process HTTP request and send file contents as chunked HTTP response
[5 points]
o Additional feature: Process HTTP request, run a given command, and send output
of the command as chunked HTTP response [10 points]
o Browser screenshot: A screenshot showing full window of a browser (along with
location bar) showing correct operation of the base case from a browser.
DUE DATE: 11:59 PM (before Midnight) on Wed Oct 7 2020
Page 2 of 3
o Formatting, Good organization, code reuse, documentation, etc. – earned fully
only if base & additional functionality operate correctly: [3 + 3 = 6 points].
• -1 Points: for each warning generated by the compiler when using Miami University C++
project (warnings are most likely sources of errors in C++ programs)
• -25 Points: If global variables (without namespaces) are used.
Develop an amazing custom web-server
Background
In this homework you will be developing a simple program to process HTTP requests and
generate responses. Recollect that HTTP is a multi-line text protocol that is used by World Wide
Web (WWW), an application running on the Internet. In this project, you will be developing a
program to respond to HTTP requests. Overall this program is essentially just string
processing from I/O streams with most of the core functionality already provided by
starter code or from previous exercise(s).
Setup
You are given headers and source files that provide several
functionalities. The ChildProcess class is exactly the same
one developed in lab exercises. The main file is essentially a
minor extension from Homework #1 (with url_decode method
added). Nevertheless, review these files to form a mental model
what you already have available. Then write pseudocode to plan
out the operations you want to get done. Then go about implementing your solution. The setup of
all of the files in NetBeans is show in the adjacent screenshot. All the files have been scp’d to
the project folder.
Testing via a browser
The starter code enables the program to run as a web-server on an available port number. The
starter code prints the port number, say 3456. Each time the program is run, the port number
will change. Given a port number, say 3456, you must test the program via a web-server by
suitably changing the command and arguments in the following URL:
1. http://os1.csi.miamioh.edu:3456/cgi-bin/exec?cmd=ls -l
2. http://os1.csi.miamioh.edu:3456/cgi-bin/exec?cmd=echo ”hello”
3. http://os1.csi.miamioh.edu:3456/test.txt
Request Processing Requirements
You are required to implement the serveClient method in main.cpp file in the supplied
starter code. This method must be implemented (using additional helper methods to be
implemented by you) to process a HTTP GET request in the following manner:
• Base case – Return output of a given file [5 points]: If the input GET line does not
start with “GET /cgi-bin/exec” then assume this request is for a given file. Use the
supplied HTTPFile class method to return the contents of a given file as shown in the
example below. Ensure you url decode the path first (using supplied helper method).
os << http::file(path); DUE DATE: 11:59 PM (before Midnight) on Wed Oct 7 2020 Page 3 of 3 • Additional case – Return output of a program [10 points]: If the input GET line starts with “GET /cgi-bin/exec?cmd=ls%20-l” then run the command specified after the cmd= as in ls -l (in this example). Of course, use the supplied ChildProcess class which is the one you developed in prior exercise. Functional testing When testing your program during development, simply copy-paste the inputs to your program (mimicking as if you manually typed the inputs). Once you have done the basic testing you may redirect input and output for testing as shown below. Several test inputs and expected output files are also supplied to streamline your testing as shown below: $ ./hw3 test_files/base_case1_inputs.txt > my_base_case1_output.txt
$ diff my_base_case1_output.txt test_files/base_case1_outputs.txt
Note: If your solution is correct, then the above diff command will not print any output.
Ensure you test with all input files and corresponding expected outputs to check all
features of your program.
Browser testing [3 points]
you must test the program via a web-server by suitably changing the port number in the
following URL: http://os1.csi.miamioh.edu:3456/exec.html. You should see a from
as shown in the adjacent screenshot. Enter the
command ls -la ./ as shown in the
screenshot and click the “Run command on
server” button. You should see the output of
the command on your browser window.
Congratulations! Now, you have a fully
operational web-server. This type of webserver is what is used to run programs in other
languages like php, php/Laravel, python, etc.
Now make a screenshot of your entire browser window (clearly showing URL in location bar)
and submit the image (saved as jpeg/jpg file) it along with your source code.
Submit to Canvas
This homework assignment must be turned-in electronically via CODE Canvas plug-in. Ensure all
of your program(s) compile without any warnings or style violations and operate correctly. Once
you have tested your implementation, upload:
1. Your updated C++ source file named with the convention MUID_hw5.cpp onto Canvas.
2. Upload screenshot of web-browser showing output of running specified command.
Upload each file associated with homework (or lab exercises) individually to Canvas. Do not
upload archive file formats such as zip/tar/gz/7zip/rar etc.
Your screenshot should show
output of running the command!
