clop

clop

clop 是一款基于struct的命令行解析器，麻雀虽小，五脏俱全。(从零实现)

feature

• 支持环境变量绑定 env DEBUG=xx ./proc
• 支持参数搜集 cat a.txt b.txt，可以把a.txt, b.txt散装成员归归类，收集到你指定的结构体成员里
• 支持短选项proc -d 或者长选项proc --debug不在话下
• posix风格命令行支持，支持命令组合ls -ltr是ls -l -t -r简写形式，方便实现普通posix 标准命令
• 子命令支持，方便实现git风格子命令git add ，简洁的子命令注册方式，只要会写结构体就行，3,4,5到无穷尽子命令也支持，只要你喜欢，用上clop就可以实现
• 默认值支持default:"1"，支持多种数据类型，让你省去类型转换的烦恼
• 贴心的重复命令报错
• 严格的短选项，长选项报错。避免二义性选项诞生
• 效验模式支持，不需要写一堆的if x!= "" or if y!=0浪费青春的代码
• 可以获取命令优先级别，方便设置命令别名

内容

• Installation
• Quick start
• example
  • 1. How to use required tags
  • 2. Support environment variables
  • 3. Set default value
  • 4. How to implement git style commands
  • 5. Get command priority
  • 6. Can only be set once
  • 7. Support arrays
• Implementing linux command options
  • cat

Installation

go get github.com/guonaihong/clop

Quick start

package main

import (
	"fmt"
	"github.com/guonaihong/clop"
)

type Hello struct {
	File string `clop:"-f; --file" usage:"file"`
}

func main() {

	h := Hello{}
	clop.Bind(&h)
	fmt.Printf("%#v\n", h)
}
// ./one -f test
// main.Hello{File:"test"}
// ./one --file test
// main.Hello{File:"test"}

example

required flag

package main

import (
	"github.com/guonaihong/clop"
)

type curl struct {
	Url string `clop:"-u; --url" usage:"url" valid:"required"`
}

func main() {

	c := curl{}
	clop.Bind(&c)
}

// ./required 
// error: -u; --url must have a value!
// For more information try --help

set default value

可以使用default tag设置默认值，普通类型直接写，复合类型用json表示

package main

import (
    "fmt"
    "github.com/guonaihong/clop"
)

type defaultExample struct {
    Int          int       `default:"1"`
    Float64      float64   `default:"3.64"`
    Float32      float32   `default:"3.32"`
    SliceString  []string  `default:"[\"one\", \"two\"]"`
    SliceInt     []int     `default:"[1,2,3,4,5]"`
    SliceFloat64 []float64 `default:"[1.1,2.2,3.3,4.4,5.5]"`
}

func main() {
    de := defaultExample{}
    clop.Bind(&de)
    fmt.Printf("%v\n", de) 
}
// run
//         ./use_def
// output:
//         {1 3.64 3.32 [one two] [1 2 3 4 5] [1.1 2.2 3.3 4.4 5.5]}

Support environment variables

// file name use_env.go
package main

import (
	"fmt"
	"github.com/guonaihong/clop"
)

type env struct {
	OmpNumThread string `clop:"env=omp_num_thread" usage:"omp num thread"`
	Path         string `clop:"env=XPATH" usage:"xpath"`
	Max          int    `clop:"env=MAX" usage:"max thread"`
}

func main() {
	e := env{}
	clop.Bind(&e)
	fmt.Printf("%#v\n", e)
}
// run
// env XPATH=`pwd` omp_num_thread=3 MAX=4 ./use_env 
// output
// main.env{OmpNumThread:"3", Path:"/home/guo", Max:4}

subcommand

package main

import (
	"fmt"
	"github.com/guonaihong/clop"
)

type add struct {
	All      bool     `clop:"-A; --all" usage:"add changes from all tracked and untracked files"`
	Force    bool     `clop:"-f; --force" usage:"allow adding otherwise ignored files"`
	Pathspec []string `clop:"args=pathspec"`
}

type mv struct {
	Force bool `clop:"-f; --force" usage:"allow adding otherwise ignored files"`
}

type git struct {
	Add add `clop:"subcommand=add" usage:"Add file contents to the index"`
	Mv  mv  `clop:"subcommand=mv" usage:"Move or rename a file, a directory, or a symlink"`
}

func main() {
	g := git{}
	clop.Bind(&g)
	fmt.Printf("git:%#v\n", g)
	fmt.Printf("git:set mv(%t) or set add(%t)\n", clop.IsSetSubcommand("mv"), clop.IsSetSubcommand("add"))
}
// run:
// ./git add -f

// output:
// git:main.git{Add:main.add{All:false, Force:true, Pathspec:[]string(nil)}, Mv:main.mv{Force:false}}
// git:set mv(false) or set add(true)

Get command priority

package main

import (
	"fmt"
	"github.com/guonaihong/clop"
)

type cat struct {
	NumberNonblank bool `clop:"-b;--number-nonblank"
                             usage:"number nonempty output lines, overrides"`

	ShowEnds bool `clop:"-E;--show-ends"
                       usage:"display $ at end of each line"`
}

func main() {

	c := cat{}
	clop.Bind(&c)

	if clop.GetIndex("number-nonblank") < clop.GetIndex("show-ends") {
		fmt.Printf("cat -b -E\n")
	} else {
		fmt.Printf("cat -E -b \n")
	}
}
// cat -be 
// 输出 cat -b -E
// cat -Eb
// 输出 cat -E -b

Can only be set once

package main

import (
    "github.com/guonaihong/clop"
)

type Once struct {
    Debug bool `clop:"-d; --debug; once" usage:"debug mode"`
}

func main() {
    o := Once{}
    clop.Bind(&o)
}
/*
./once -debug -debug
error: The argument '-d' was provided more than once, but cannot be used multiple times
For more information try --help
*/

Support arrays

加上greedy属性，就支持数组贪婪写法。类似join命令。 如不加，就是类似于curl -H 的写法

package main

import (
    "fmt"

    "github.com/guonaihong/clop"
)

type test struct {
    A []int `clop:"-a;greedy" usage:"test array"`
    B int   `clop:"-b" usage:"test int"`
}

func main() {
    a := &test{}
    clop.Bind(a)
    fmt.Printf("%#v\n", a)
}
/*
运行
./use_array -a 12 34 56 78 -b 100
输出
&main.test{A:[]int{12, 34, 56, 78}, B:100}
*/

Implementing linux command options

cat

package main

import (
	"fmt"
	"github.com/guonaihong/clop"
)

type cat struct {
	NumberNonblank bool `clop:"-c;--number-nonblank" 
	                     usage:"number nonempty output lines, overrides"`

	ShowEnds bool `clop:"-E;--show-ends" 
	               usage:"display $ at end of each line"`

	Number bool `clop:"-n;--number" 
	             usage:"number all output lines"`

	SqueezeBlank bool `clop:"-s;--squeeze-blank" 
	                   usage:"suppress repeated empty output lines"`

	ShowTab bool `clop:"-T;--show-tabs" 
	              usage:"display TAB characters as ^I"`

	ShowNonprinting bool `clop:"-v;--show-nonprinting" 
	                      usage:"use ^ and M- notation, except for LFD and TAB" `

	Files []string `clop:"args=files"`
}

func main() {

	c := cat{}
	err := clop.Bind(&c)

	fmt.Printf("%#v, %s\n", c, err)
}

/*
Usage:
    ./cat [Flags] <files> 

Flags:
    -E,--show-ends           display $ at end of each line 
    -T,--show-tabs           display TAB characters as ^I 
    -c,--number-nonblank     number nonempty output lines, overrides 
    -n,--number              number all output lines 
    -s,--squeeze-blank       suppress repeated empty output lines 
    -v,--show-nonprinting    use ^ and M- notation, except for LFD and TAB 

Args:
    <files>
*/