MyCalc - A Command-Line Calculator (C-based REPL)

Overview

MyCalc is a lightweight, command-line-based calculator that functions like a REPL (Read-Eval-Print Loop).
It dynamically compiles expressions using C, allowing users to evaluate:

• Arithmetic expressions
• Trigonometric functions (in degrees)
• Factorials
• Prime number calculations
• Other mathematical functions

Originally started in the 2020–2021 academic year during the COVID-19 lockdown, this project was one of my earliest explorations into programming logic. In 2025, it was modernized with Makefile support, cross-platform compatibility, and cleanup logic.

Features

• Basic Arithmetic: +, -, *, /, ()
• Trigonometry (Radians): sin(x), cos(x), tan(x) (accepts radians)
• Trigonometry (Degrees): sin_deg(x), cos_deg(x), tan_deg(x) (accepts degrees)
• Logarithms: log(x), log10(x)
• Factorial Calculation: fact(n) (Supports up to fact(20))
• Power Functions: pow(base, exponent)
• Prime Number Utilities:
  • Check if a number is prime → isprime(n)
  • Find the nth prime → nth_prime(n)
• Reverse a Number: reverse(n)
• Find Factors: factors(n)
• Dynamic Help Commands:
  • help() → Displays a static list of available functions and usage examples.
  • help_all() → Dynamically lists all functions defined in wincalc.h.
• Special Command:
  • exit() → Exits the calculator and triggers cleanup.

How to Install & Run

1. Clone the repository:

   git clone https://github.com/wineel10/MyCalc.git
   cd MyCalc

2. Run the calculator:

   make run

   • The calculator now supports colored result output (bright green)
   • Works on macOS, Linux, and Windows (via WSL, Git Bash, or MinGW)

3. Enter expressions and see instant results:

   >>> 1+2
   3
   >>> sin(90)
   1
   >>> fact(5)
   120
   >>> help()
   >>> help_all()
   

4. To exit, type:

   >>> exit()
   

5. Auto Cleanup:

   • When you exit, win.h, input.exe, and output.exe are automatically deleted for security.

Terminal Colors

Results are printed in bright green using ANSI escape codes.

Cross-Platform Makefile

The provided Makefile:

• Detects Windows vs macOS/Linux
• Uses correct file delete and null device syntax per OS
• Supports dynamic recompilation in a REPL loop

Available Functions

Function	Description	Example	Output
1+2	Basic Arithmetic	1+2	3
sin(90)	Sine (in degrees)	sin(90)	1
fact(5)	Factorial	fact(5)	120
isprime(11)	Prime number check	isprime(11)	1 (true)
nth_prime(5)	Find the 5th prime	nth_prime(5)	11
reverse(1234)	Reverse the number	reverse(1234)	4321
factors(10)	Find factors of 10	factors(10)	1 2 5 10
help()	Show static function list	help()	Displays usage examples
help_all()	Dynamically list functions	help_all()	Reads wincalc.h
exit()	Exit the calculator	exit()	Program closes

Project Structure

MyCalc
│──  Input.c           # Takes user input, generates win.h
│──  Output.c          # Executes the calculation
│──  wincalc.h         # Math functions, including trigonometry in degrees
│──  Makefile          # Cross-platform build and run automation
│──  README.md         # Documentation on how to use the project
│──  .gitignore        # Prevents unnecessary files from being committed

.gitignore (Files That Should NOT Be Uploaded)

*.exe
.vscode/
win.h
errors.log
*.o
*.obj
input
output
exit_marker.txt

These files are auto-generated during compilation and should NOT be committed to GitHub.

Why This Project?

Started during the 2020–2021 academic year at the time of COVID-19 lockdowns, this was one of my earliest programming experiments in C. In 2025, I enhanced it with professional touches like Makefile automation, cross-platform support, and ANSI-colored output.It demonstrates:

• How to use C as a REPL
• How Makefile or batch/shell files can control execution flow
• How real-time mathematical expression evaluation works in C

Future Improvements

• Improve UI/UX (colored output, better formatting)
• Support for more math functions (e.g., modulus, permutations, combinations)
• Cross-platform compatibility (Linux/macOS/Windows with make or shell scripts)
• Enhance security (prevent unintended code execution)

License

This project is open-source and licensed under the MIT License.
Feel free to modify and improve upon it!

Author

• WINEEL WILSON DASARI
• wineel10wilson@gmail.com
• GitHub: wineel10