mirror of
https://github.com/cheat/cheat.git
synced 2024-12-18 18:55:06 +01:00
117 lines
3.8 KiB
Markdown
117 lines
3.8 KiB
Markdown
docopt-go
|
|
=========
|
|
|
|
[](https://travis-ci.org/docopt/docopt.go)
|
|
[](https://coveralls.io/github/docopt/docopt.go)
|
|
[](https://godoc.org/github.com/docopt/docopt.go)
|
|
|
|
An implementation of [docopt](http://docopt.org/) in the [Go](http://golang.org/) programming language.
|
|
|
|
**docopt** helps you create *beautiful* command-line interfaces easily:
|
|
|
|
```go
|
|
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"github.com/docopt/docopt-go"
|
|
)
|
|
|
|
func main() {
|
|
usage := `Naval Fate.
|
|
|
|
Usage:
|
|
naval_fate ship new <name>...
|
|
naval_fate ship <name> move <x> <y> [--speed=<kn>]
|
|
naval_fate ship shoot <x> <y>
|
|
naval_fate mine (set|remove) <x> <y> [--moored|--drifting]
|
|
naval_fate -h | --help
|
|
naval_fate --version
|
|
|
|
Options:
|
|
-h --help Show this screen.
|
|
--version Show version.
|
|
--speed=<kn> Speed in knots [default: 10].
|
|
--moored Moored (anchored) mine.
|
|
--drifting Drifting mine.`
|
|
|
|
arguments, _ := docopt.ParseDoc(usage)
|
|
fmt.Println(arguments)
|
|
}
|
|
```
|
|
|
|
**docopt** parses command-line arguments based on a help message. Don't write parser code: a good help message already has all the necessary information in it.
|
|
|
|
## Installation
|
|
|
|
⚠ Use the alias "docopt-go". To use docopt in your Go code:
|
|
|
|
```go
|
|
import "github.com/docopt/docopt-go"
|
|
```
|
|
|
|
To install docopt in your `$GOPATH`:
|
|
|
|
```console
|
|
$ go get github.com/docopt/docopt-go
|
|
```
|
|
|
|
## API
|
|
|
|
Given a conventional command-line help message, docopt processes the arguments. See https://github.com/docopt/docopt#help-message-format for a description of the help message format.
|
|
|
|
This package exposes three different APIs, depending on the level of control required. The first, simplest way to parse your docopt usage is to just call:
|
|
|
|
```go
|
|
docopt.ParseDoc(usage)
|
|
```
|
|
|
|
This will use `os.Args[1:]` as the argv slice, and use the default parser options. If you want to provide your own version string and args, then use:
|
|
|
|
```go
|
|
docopt.ParseArgs(usage, argv, "1.2.3")
|
|
```
|
|
|
|
If the last parameter (version) is a non-empty string, it will be printed when `--version` is given in the argv slice. Finally, we can instantiate our own `docopt.Parser` which gives us control over how things like help messages are printed and whether to exit after displaying usage messages, etc.
|
|
|
|
```go
|
|
parser := &docopt.Parser{
|
|
HelpHandler: docopt.PrintHelpOnly,
|
|
OptionsFirst: true,
|
|
}
|
|
opts, err := parser.ParseArgs(usage, argv, "")
|
|
```
|
|
|
|
In particular, setting your own custom `HelpHandler` function makes unit testing your own docs with example command line invocations much more enjoyable.
|
|
|
|
All three of these return a map of option names to the values parsed from argv, and an error or nil. You can get the values using the helpers, or just treat it as a regular map:
|
|
|
|
```go
|
|
flag, _ := opts.Bool("--flag")
|
|
secs, _ := opts.Int("<seconds>")
|
|
```
|
|
|
|
Additionally, you can `Bind` these to a struct, assigning option values to the
|
|
exported fields of that struct, all at once.
|
|
|
|
```go
|
|
var config struct {
|
|
Command string `docopt:"<cmd>"`
|
|
Tries int `docopt:"-n"`
|
|
Force bool // Gets the value of --force
|
|
}
|
|
opts.Bind(&config)
|
|
```
|
|
|
|
More documentation is available at [godoc.org](https://godoc.org/github.com/docopt/docopt-go).
|
|
|
|
## Unit Testing
|
|
|
|
Unit testing your own usage docs is recommended, so you can be sure that for a given command line invocation, the expected options are set. An example of how to do this is [in the examples folder](examples/unit_test/unit_test.go).
|
|
|
|
## Tests
|
|
|
|
All tests from the Python version are implemented and passing at [Travis CI](https://travis-ci.org/docopt/docopt-go). New language-agnostic tests have been added to [test_golang.docopt](test_golang.docopt).
|
|
|
|
To run tests for docopt-go, use `go test`.
|