[golang]写了一个可以用 go 来写脚本的工具：gosl

转自：https://golangtc.com/t/53cca103320b52060a000030

写了一个可以用 go 来写脚本的工具：gosl

代码和使用说明可以看这里： http://github.com/daviddengcn/gosl

Go Search 已经完全用 gosl 来启动了。

相比 bash/Python 写脚本的好处：

1. 纯 Go 语言，没有新的学习成本
2. 引入预先导入的 package 和预定义的内置函数，方便脚本书写
3. 可以无缝的和 Go 项目衔接，例如可以直接读取数据和配置。
4. 和 Go 有相同的执行效率，大大快过 Python

这里贴一个简单的例子：

#!/bin/gosl

APPS := []string {
  "tocrawl", "crawler", "mergedocs", "indexer",
}

for {
  for _, app := range APPS {
    Printf("Running %s...\n", app)
    Bash(app)
  }
}

gosl 

This is an application that can make you write script with the Go language.

It is NOT an interpreter but the pure Go. The preprocessor tranforms the script into a Go program, instantly compiles and runs. So it is almost same as the standard Go with the same efficiency.

Benefit

1. Pure Go language. No need to learn a new script language.
2. Pre-imported packages and pre-defined functions make it easy to code.
3. Seamless integration with the Go project. E.g. can easily load configuration or data file from the Go project.
4. Running efficiency same as Go, much faster than Python.

Example

• Simple

#!/bin/gosl

import "encoding/json"

toJson := func(lines []string) string {
  res, _ := json.Marshal(struct {
    Lines []string `json:"lines"`
  }{
    Lines: lines,
  })
  return string(res)
}

files := BashEval("ls -l %s", "/tmp/")

Println(toJson(Split(files, "\n")))
    

• Go Search is now operating with gosl. So you can find some good examples at: https://github.com/daviddengcn/gcse/tree/master/scripts
• go-diff also provides scripts in gosl: https://github.com/daviddengcn/go-diff/tree/master/scripts

Installation and Usage

Download and install the package

go get github.com/daviddengcn/gosl
go install github.com/daviddengcn/gosl

(Optional) Link to /bin

sudo ln -s $GOPATH/bin/gosl /bin/gosl

If you don't want to do this, the interpreter line can be like this, assuming $GOPATH/bin is in your $PATH:

#!/usr/bin/env gosl

Run a script

If a script starts with the bash interpreter line: #!/bin/gosl. You can run it like this

chmod a+x example.gs
./example.gs [params...]

Or you can explictly call gosl to run it:

gosl example.gs [params...]

Pre-imported Packages

The following packages are pre-imported with ., i.e. you can directly use the methods exported by them. No complain of the compiler if you don't use them.

fmt, os, strings, strconv, math, time, and github.com/daviddengcn/gosl/builtin

Frequently Used builtin Functions

Method	Description	Example
S	Convert anything to a string	S(1234) == "123"
I	Convert anything to an int	I("1234") == 1234
BashEval	Similar to bash backtick substitution.	lsstr := BashEval("ls -l")
Exec	Execute an command with arguments	err, code := Exec("rm", "-rf" "tmp")
Bash	Execute a bash line	err, code := Bash("rm -rf tmp")
ScriptDir	Returns the directory of the script	file := ScriptDir() + "/" + fn

More functions are defined in package daviddengcn/gosl/builtin/ (godoc)