Find/Replace in multiple files

main.go

package main

import (
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"
)

func visit(find string, replace string) filepath.WalkFunc {
	return func(path string, fi os.FileInfo, err error) error {

		if err != nil {
			return err
		}

		if !!fi.IsDir() {
			return nil //
		}

		matched, err := filepath.Match("*", fi.Name())

		if err != nil {
			panic(err)
			return err
		}

		if matched {
			read, err := ioutil.ReadFile(path)
			if err != nil {
				panic(err)
			}

			newContents := strings.Replace(string(read), find, replace, -1)

			err = ioutil.WriteFile(path, []byte(newContents), 0)
			if err != nil {
				panic(err)
			}

		}

		return nil
	}
}

func main() {
	path := os.Args[1]
	find := os.Args[2]
	replace := os.Args[3]

	err := filepath.Walk(path, visit(find, replace))
	if err != nil {
		panic(err)
	}
}