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https://github.com/alfredxing/calc

A simple command-line calculator written in Go
https://github.com/alfredxing/calc

Last synced: 3 months ago
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A simple command-line calculator written in Go

Host: GitHub
URL: https://github.com/alfredxing/calc
Owner: alfredxing
License: mit
Archived: true
Created: 2015-02-14T00:19:03.000Z (about 10 years ago)
Default Branch: master
Last Pushed: 2023-05-06T16:31:10.000Z (almost 2 years ago)
Last Synced: 2024-06-18T13:53:14.078Z (8 months ago)
Language: Go
Homepage:
Size: 36.1 KB
Stars: 459
Watchers: 10
Forks: 49
Open Issues: 6
Metadata Files:
- Readme: README.md
- License: LICENSE

Awesome Lists containing this project

README

## calc

[![GoDoc](https://godoc.org/github.com/alfredxing/calc?status.svg)](https://godoc.org/github.com/alfredxing/calc) [![Build Status](https://travis-ci.org/alfredxing/calc.svg?branch=master)](https://travis-ci.org/alfredxing/calc)

A simple, fast, and intuitive command-line calculator written in Go.

### Install
Install calc as you would any other Go program:
```
go get github.com/alfredxing/calc
```

### Usage
You can use calc in two ways: shell mode and command.

#### Shell mode
This is probably the mode you'll want to use. It's like the `python` shell or `irb`. The shell mode uses the `terminal` package provided by [`golang.org/x/crypto/ssh/terminal`](https://godoc.org/golang.org/x/crypto/ssh/terminal), which means it supports many of the shell features you know and love (like history, pasting, and the `exit` command).
```shell
> 1+1
2
> 3(5/(3-4))
-15
> 3pi^2
29.608813203268074
> @+1
30.608813203268074
> @@@*2
-30
> ln(-1)
NaN
```

#### Command
You can also use calc to evaluate an expression with just a single command (i.e. without opening the shell). To do this, just use `calc [expression]`:
```shell
bash$ calc 1+1
2
bash$
```

### Supported functions, operators, and constants
calc supports all the standard stuff, and I'm definitely adding more later (also feel free to fork and add your own!)

##### Operators
`+`, `-`, `*`, `/`, `^`, `%`

##### Functions
`sin`, `cos`, `tan`, `cot`, `sec`, `csc`, `asin`, `acos`, `atan`, `acot`, `asec`, `acsc`, `sqrt`, `log`, `lg`, `ln`, `abs`

##### Constants
`e`, `pi`, `π`

##### History
Previous results can be accessed with the `@` symbol. A single `@` returns the result of the last computation, while multiple `@` gets the n^th last result, where n is the number of `@`s used (for example, `@@` returns the second-last result, `@@@@@` returns the fifth-last result).

### Why not use ...?
- Google
- Doesn't work without an internet connection
- Slower
- Doesn't show previous computations, so you end up with multiple tabs open at once.
- Spotlight (on OS X)
- No history
- Switching between Spotlight and other windows isn't too fun
- Python/IRB
- Requires use of a separate math module for most functions and constants
- A little bit slower to start up
- `bc`
- Limited number of built-in functions; these have shortened (not too intuitive) names as well.

The alternatives above are all great, and have their own advantages over calc. I highly recommend looking into these if you don't like how calc works.