Fast Console Calculator: Features, Shortcuts, and Tips

Features

• Lightweight CLI: Minimal dependencies; runs in any terminal.
• Basic arithmetic: +, −, ×, ÷ with correct operator precedence.
• Floating-point & integers: Automatic type handling and configurable precision.
• Expression evaluation: Parentheses, unary operators, exponentiation, modulus, and factorial.
• Variables: Define and reuse variables (e.g., x = 3.5).
• History: Scrollable command history and optional persistent history file.
• Scripting mode: Run a file of expressions or commands non-interactively.
• Configurable output: Change number formatting, rounding mode, and significant digits.
• Unit conversions: Built-in common conversions (length, mass, time) or plugin support.
• Extensibility: Plugin or macro support for custom functions (e.g., finance, stats).
• Error handling: Clear parse and runtime error messages with location hints.
• Secure eval: No arbitrary code execution — expression parser, not raw eval.

Shortcuts & Keybindings

• Ctrl+R: Reverse search through history.
• Ctrl+L: Clear screen.
• Ctrl+A / Ctrl+E: Jump to line start/end.
• Alt+Left / Alt+Right: Move cursor by word.
• Tab: Auto-complete function names, variables, and constants.
• Shift+Enter: Insert newline for multi-line expressions.
• Enter: Evaluate current expression.
• Up / Down: Navigate previous commands.
• Ctrl+K: Delete to end of line.
• Esc then number: Quickly recall entry N from history (optional).

Tips for Power Users

1. Use variables for complex results: Save intermediate values (a = 2*sqrt(5)) to reuse without retyping.
2. Script repetitive tasks: Put sequences of calculations in a .calc script and run in batch mode.
3. Set precision per-session: Adjust decimal places for financial vs scientific work.
4. Create macros: Define frequently used expressions (e.g., VAT(price) = price1.20).
5. Combine with CLI tools: Pipe output to awk/sed or redirect to files for logging.
6. Leverage plugins: Add domain-specific functions (statistics, matrices, crypto).
7. Use parentheses liberally: Makes intent clear and avoids precedence mistakes.
8. Enable persistent history: Recover prior sessions and build a searchable calculation log.
9. Test edge cases: Verify behavior for division by zero, large factorials, and precision limits.
10. Secure sharing: Export scripts or saved variables without embedding sensitive data.

Example Commands

Code
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# Basic 2+3*4

 
Variables and functions
 
pi = 3.141592653589793 r = 5 area = pi * r^2
 
Unit conversion (if supported)
 
100 km to mi
 
Batch mode
 
calc –run myscript.calc 

If you want, I can produce a minimal Python implementation, a config file, or a plugin example.