【GO】如何用 Golang 的 os/exec 执行 pipe 替换文件

背景

主要记录一下怎么用 Golang 的 os/exec 去执行一个 cmd 的 pipeline，就是拿 cmdA 的输出作为 cmdB 的输入

代码

package main

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"strings"
)

// *java.Object

func main() {
	// 定义正则表达式
	regex := regexp.MustCompile(`\*java\.Object\b`)

	// 要替换的字符串
	data := "var obj *java.Object"

	// 替换字符串
	data = regex.ReplaceAllString(data, "java.Object")

	// 打印替换后的字符串
	fmt.Println(data)
	err := replaceObject("/Users/edy/Workspace/GoWorkspace/awesomeProject/pipelinedemo")
	panic(err)
}

var JavaObjectRe = regexp.MustCompile(`b\*java\.Object`)

func replaceObject(path string) error {
	fs, err := os.ReadDir(path)
	if err != nil {
		return err
	}

	for _, f := range fs {
		fileName := filepath.Join(path, f.Name())
		if f.IsDir() {
			if err = replaceObject(fileName); err != nil {
				return err
			}
		} else if strings.HasSuffix(f.Name(), ".go") {
			data, err := os.ReadFile(fileName)
			if err != nil {
				return err
			}

			if err = replaceJavaObject(data, fileName); err != nil {
				return err
			}
		}
	}

	handlerName := filepath.Join(path, "handler.go")
	handler, err := os.ReadFile(handlerName)
	if err != nil {
		return err
	}

	if err = replaceJavaObject(handler, handlerName); err != nil {
		return err
	}

	return nil
}

func replaceJavaObject(content []byte, fileName string) error {
	aaaa := JavaObjectRe.Find(content)
	println(string(aaaa))
	content = JavaObjectRe.ReplaceAll(content, []byte("java.Object"))
	err := os.WriteFile(fileName, content, 0644)
	if err != nil {
		return err
	}

	return nil
}

func demo1() {
	findGo := exec.Command("find", ".", "-name", "*.go")
	sout, err := findGo.StdoutPipe()
	if err != nil {
		panic(err)
		return
	}

	bakGo := exec.Command("xargs", "sed", "-i", "-bak", "-e", "s/\\*java\\.Object/java\\.Object/g")
	bakGo.Stdin = sout
	bakGo.Stdout = os.Stdout

	err = findGo.Start()
	if err != nil {
		panic(err)
	}

	err = bakGo.Start()
	if err != nil {
		panic(err)
	}

	err = findGo.Wait()
	if err != nil {
		panic(err)
	}

	err = bakGo.Wait()
	if err != nil {
		panic(err)
	}
}