initial import

main.go

@@ -0,0 +1,178 @@
+// Copyright 2016 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This program ensures source code files have copyright license headers.
+// See usage with "addlicence -h".
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+)
+
+const helpText = `Usage: addlicense [flags] pattern [pattern ...]
+
+The program ensures source code files have copyright license headers
+by scanning directory patterns recursively.
+
+It modifies all source files in place and avoids adding a license header
+to any file that already has one.
+
+The pattern argument can be provided multiple times, and may also refer
+to single files.
+
+Flags:
+`
+
+var (
+	holder  = flag.String("c", "Google Inc.", "copyright holder")
+	license = flag.String("l", "apache", "license type: apache, mit")
+	year    = flag.Int("y", time.Now().Year(), "year")
+)
+
+func main() {
+	flag.Usage = func() {
+		fmt.Fprintln(os.Stderr, helpText)
+		flag.PrintDefaults()
+	}
+	flag.Parse()
+	if flag.NArg() == 0 {
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	data := &copyrightData{
+		Year:   *year,
+		Holder: *holder,
+	}
+
+	// process at most 1000 files in parallel
+	ch := make(chan *file, 1000)
+	done := make(chan struct{})
+	go func() {
+		var wg sync.WaitGroup
+		for f := range ch {
+			wg.Add(1)
+			go func(f *file) {
+				err := addLicense(f.path, f.mode, *license, data)
+				if err != nil {
+					log.Printf("%s: %v", f.path, err)
+				}
+				wg.Done()
+			}(f)
+		}
+		wg.Wait()
+		close(done)
+	}()
+
+	for _, d := range flag.Args() {
+		walk(ch, d)
+	}
+	close(ch)
+	<-done
+}
+
+type file struct {
+	path string
+	mode os.FileMode
+}
+
+func walk(ch chan<- *file, start string) {
+	filepath.Walk(start, func(path string, fi os.FileInfo, err error) error {
+		if err != nil {
+			log.Printf("%s error: %v", path, err)
+			return nil
+		}
+		if fi.IsDir() {
+			return nil
+		}
+		ch <- &file{path, fi.Mode()}
+		return nil
+	})
+}
+
+func addLicense(path string, fmode os.FileMode, typ string, data *copyrightData) error {
+	var lic []byte
+	var err error
+	switch filepath.Ext(path) {
+	default:
+		return nil
+	case ".c", ".h":
+		lic, err = prefix(typ, data, "/*", " * ", " */")
+	case ".js", ".css":
+		lic, err = prefix(typ, data, "/**", " * ", " */")
+	case ".cc", ".cpp", ".cs", ".go", ".hh", ".hpp", ".java", ".m", ".mm", ".proto", ".rs", ".scala", ".swift", ".dart":
+		lic, err = prefix(typ, data, "", "// ", "")
+	case ".py", ".sh":
+		lic, err = prefix(typ, data, "", "# ", "")
+	case ".el", ".lisp":
+		lic, err = prefix(typ, data, "", ";; ", "")
+	case ".erl":
+		lic, err = prefix(typ, data, "", "% ", "")
+	case ".hs":
+		lic, err = prefix(typ, data, "", "-- ", "")
+	case ".html", ".xml":
+		lic, err = prefix(typ, data, "<!--", " ", "-->")
+	case ".php":
+		lic, err = prefix(typ, data, "<?php", "// ", "?>")
+	}
+	if err != nil || lic == nil {
+		return err
+	}
+
+	b, err := ioutil.ReadFile(path)
+	if err != nil || hasLicense(b) {
+		return err
+	}
+
+	line := hashBang(b)
+	if len(line) > 0 {
+		b = b[len(line):]
+		if line[len(line)-1] != '\n' {
+			line = append(line, '\n')
+		}
+		lic = append(line, lic...)
+	}
+	b = append(lic, b...)
+	return ioutil.WriteFile(path, b, fmode)
+}
+
+func hashBang(b []byte) []byte {
+	var line []byte
+	for _, c := range b {
+		line = append(line, c)
+		if c == '\n' {
+			break
+		}
+	}
+	if bytes.HasPrefix(line, []byte("#!")) {
+		return line
+	}
+	return nil
+}
+
+func hasLicense(b []byte) bool {
+	n := 1000
+	if len(b) < 1000 {
+		n = len(b)
+	}
+	return bytes.Contains(bytes.ToLower(b[:n]), []byte("copyright"))
+}