Submit: Turn in your basecalc.c source file using the turnin command on morbius.mscsnet.mu.edu or one of the other Systems Lab machines.

Work is to be completed individually. Be certain to include your name in the file. You may submit multiple times, but only the last turnin will be kept. The automatic submission system will not accept work after the deadline. (See turnin instructional video HERE. Note that the video is for a different course number, and that Morbius's domain name has changed since the video was made: morbius.mscs.mu.edu -> morbius.mscsnet.mu.edu)

Include a comment block at the very top of each file that contains the following:

/**
 * COSC 3250 - Project 1
 * Explain briefly the functionality of the program.
 * @author [your name]
 * Instructor [your instructor]
 * TA-BOT:MAILTO [your email address]
 */


All Your Base Are Belong To Us^*

Write a calculator program that reads in expressions consisting of integers and the operators +, -, *, /, %, ^ (exponentiation), & (bitwise AND), | (bitwise OR), << (left shift), and >> (right shift), and prints the results when evaluated in simple left-to-right order.

Your calculator should understand positive integers in binary, octal, decimal, and hexadecimal, but all results will be decimal (base-10) integers. Binary operands will begin with "0b", followed by a string of 0s and 1s; operands in all other bases will follow the traditional C language notation.

You should use the getchar library function to read console input one character at a time. The use of any other library functions for input is not recommended at this time.

We have provided an example program for your reference, executable on Morbius as ~brylow/os/Projects/basecalc.

Notes

• The Systems Lab (CU 310) is the primary development environment for COSC 3250. It is expected that you will learn to use the required tools for developing, testing, and submitting your projects on Linux either in person or connected remotely. The Systems Lab machines are available locally in Cudahy 310, and can be accessed remotely via ssh using your CS Department credentials. (See D2L Laboratory Instructions for instructions for learning your credentials.) Free secure shell (ssh) clients are readily available for other platforms, including Windows machines at home or in the dorms. We recommend PuTTY for Windows, and the built-in ssh client in Terminal for MacOS users.
• The Systems Lab machines run the Linux operating system. If you need a refresher on using the UNIX environment, please see the UNIX Tutorial.
• This project can seem deceptively complex, but is quite tractable if you first take the time to design suitable helper functions, and test those function thoroughly before moving on to the overall calculator. We encourage the disciplined practice of test-driven development.
• The internal data representation of the calculator values can be assumed to be a signed int. You are not required to deal with overflow and underflow issues.
• Parsing input is always tedious, particularly when the input is not rigidly constrained with rules like, "all operators must be surrounded by space on both sides," (which is NOT a constraint for this assignment). Powerful tools for parsing are covered in COSC 4400 Compiler Construction and to a much lesser extent, COSC 3410 Programming Languages. In lieu of a parser-generator, consider drawing simple state diagrams for how to recognize an integer in octal, or how to recognize an integer in hexadecimal. In many cases with input of this type, it is useful to be able to put back a character of input once you realize you have read too far. Useful C routines for implementing this kind of buffering are presented in Section 4.3 of K&R, (getch() and ungetch()).
• Consider various operational and parsing errors that can take place. See the reference implementation for appropriate error messages.
• The reference implementation is considered an integral part of the specifications for this assignment. Project grades will be based in significant part upon an automated comparison of behavior against the reference implementation. Devise test cases to discover the expected behavior, and do your best to match it precisely. Creativity will be valued in later assignments, but first one must master the tools.
• Use the electronic turnin system to submit your work. The command is "turnin", followed by the name(s) of files(s) you wish to submit. The command "turnin -v" will print a listing verifying the contents of your submission. See "turnin -h" for a list of other relevant options. The system does not accept work after the deadline, and neither does the professor.

* - Early Internet meme reference, circa 2001, (en.wikipedia.org/wiki/All_your_base_are_belong_to_us)

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[Revised 2020 Aug 26 00:10 DWB]