UE4 Default Copyright Fixer

copyright_fixer.go

package main

import (
	"bytes"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"regexp"
	"strings"
)

var checker = regexp.MustCompile(`^// Fill out[^\r\n]*`)
var checkerForNew = regexp.MustCompile(`^// Copyright 2014[^\r\n]*`)
var newCopyright = []byte(`// Copyright 2014-2018 9M Interactive, Inc. All Rights Reserved.`) // modify this line to what you desire
var bom = "\xef\xbb\xbf"

func main() {
	dir := os.Args[1]
	log.Println("path", dir)

	err := filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
		if info.IsDir() {
			return nil
		}

		ext := filepath.Ext(info.Name())
		if ext != ".cpp" && ext != ".h" && ext != ".cs" {
			return nil
		}

		fileContent, err := ioutil.ReadFile(path)
		if err != nil {
			log.Println(err)
			return nil
		}

		// trim bom
		fileContent = bytes.TrimLeft(fileContent, bom)

		var newContent []byte
		if idx := checker.FindIndex(fileContent); idx != nil {
			// has copyright notice
			log.Println("has copyright")
			newContent = checker.ReplaceAll(fileContent, newCopyright)
		} else if !checkerForNew.Match(fileContent) {
			// no copyright notice
			log.Println("no copyright")
			var builder strings.Builder
			builder.Write(newCopyright)
			builder.Write([]byte("\r\n\r\n"))
			builder.Write(fileContent)

			newContent = []byte(builder.String())
		}

		if newContent != nil {
			if err := ioutil.WriteFile(path, newContent, 0644); err != nil {
				log.Println("overwrite error:", err)
			}

			log.Println("fixed", path)
		} else {
			log.Println("skipping", path)
		}

		return nil
	})

	log.Println("done", err)
}