1*9bb1b549SSpandan Das// Copyright 2017 The Bazel Authors. All rights reserved. 2*9bb1b549SSpandan Das// 3*9bb1b549SSpandan Das// Licensed under the Apache License, Version 2.0 (the "License"); 4*9bb1b549SSpandan Das// you may not use this file except in compliance with the License. 5*9bb1b549SSpandan Das// You may obtain a copy of the License at 6*9bb1b549SSpandan Das// 7*9bb1b549SSpandan Das// http://www.apache.org/licenses/LICENSE-2.0 8*9bb1b549SSpandan Das// 9*9bb1b549SSpandan Das// Unless required by applicable law or agreed to in writing, software 10*9bb1b549SSpandan Das// distributed under the License is distributed on an "AS IS" BASIS, 11*9bb1b549SSpandan Das// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12*9bb1b549SSpandan Das// See the License for the specific language governing permissions and 13*9bb1b549SSpandan Das// limitations under the License. 14*9bb1b549SSpandan Das 15*9bb1b549SSpandan Das// md5sum replicates the equivalent functionality of the unix tool of the same name. 16*9bb1b549SSpandan Daspackage main 17*9bb1b549SSpandan Das 18*9bb1b549SSpandan Dasimport ( 19*9bb1b549SSpandan Das "crypto/md5" 20*9bb1b549SSpandan Das "flag" 21*9bb1b549SSpandan Das "fmt" 22*9bb1b549SSpandan Das "io" 23*9bb1b549SSpandan Das "log" 24*9bb1b549SSpandan Das "os" 25*9bb1b549SSpandan Das "path/filepath" 26*9bb1b549SSpandan Das) 27*9bb1b549SSpandan Das 28*9bb1b549SSpandan Dasfunc md5SumFile(filename string) ([]byte, error) { 29*9bb1b549SSpandan Das var result []byte 30*9bb1b549SSpandan Das f, err := os.Open(filename) 31*9bb1b549SSpandan Das if err != nil { 32*9bb1b549SSpandan Das return result, err 33*9bb1b549SSpandan Das } 34*9bb1b549SSpandan Das defer f.Close() 35*9bb1b549SSpandan Das hash := md5.New() 36*9bb1b549SSpandan Das if _, err := io.Copy(hash, f); err != nil { 37*9bb1b549SSpandan Das return nil, err 38*9bb1b549SSpandan Das } 39*9bb1b549SSpandan Das return hash.Sum(result), nil 40*9bb1b549SSpandan Das} 41*9bb1b549SSpandan Das 42*9bb1b549SSpandan Dasfunc run(args []string) error { 43*9bb1b549SSpandan Das // Prepare our flags 44*9bb1b549SSpandan Das flags := flag.NewFlagSet("md5sum", flag.ExitOnError) 45*9bb1b549SSpandan Das output := flags.String("output", "", "If set, write the results to this file, instead of stdout.") 46*9bb1b549SSpandan Das if err := flags.Parse(args); err != nil { 47*9bb1b549SSpandan Das return err 48*9bb1b549SSpandan Das } 49*9bb1b549SSpandan Das // print the outputs if we need not 50*9bb1b549SSpandan Das to := os.Stdout 51*9bb1b549SSpandan Das if *output != "" { 52*9bb1b549SSpandan Das f, err := os.Create(*output) 53*9bb1b549SSpandan Das if err != nil { 54*9bb1b549SSpandan Das return err 55*9bb1b549SSpandan Das } 56*9bb1b549SSpandan Das defer f.Close() 57*9bb1b549SSpandan Das to = f 58*9bb1b549SSpandan Das } 59*9bb1b549SSpandan Das for _, path := range flags.Args() { 60*9bb1b549SSpandan Das walkFn := func(path string, info os.FileInfo, err error) error { 61*9bb1b549SSpandan Das if err != nil { 62*9bb1b549SSpandan Das return err 63*9bb1b549SSpandan Das } 64*9bb1b549SSpandan Das if info.IsDir() { 65*9bb1b549SSpandan Das return nil 66*9bb1b549SSpandan Das } 67*9bb1b549SSpandan Das 68*9bb1b549SSpandan Das if b, err := md5SumFile(path); err != nil { 69*9bb1b549SSpandan Das return err 70*9bb1b549SSpandan Das } else { 71*9bb1b549SSpandan Das fmt.Fprintf(to, "%s %x\n", path, b) 72*9bb1b549SSpandan Das } 73*9bb1b549SSpandan Das return nil 74*9bb1b549SSpandan Das } 75*9bb1b549SSpandan Das 76*9bb1b549SSpandan Das if err := filepath.Walk(path, walkFn); err != nil { 77*9bb1b549SSpandan Das return err 78*9bb1b549SSpandan Das } 79*9bb1b549SSpandan Das } 80*9bb1b549SSpandan Das return nil 81*9bb1b549SSpandan Das} 82*9bb1b549SSpandan Das 83*9bb1b549SSpandan Dasfunc main() { 84*9bb1b549SSpandan Das log.SetFlags(0) 85*9bb1b549SSpandan Das log.SetPrefix("GoMd5sum: ") 86*9bb1b549SSpandan Das if err := run(os.Args[1:]); err != nil { 87*9bb1b549SSpandan Das log.Fatal(err) 88*9bb1b549SSpandan Das } 89*9bb1b549SSpandan Das} 90