1// Copyright 2023 The Bazel Authors. All rights reserved. 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15package main 16 17import ( 18 "crypto/sha256" 19 "io" 20 "log" 21 "os" 22) 23 24func main() { 25 h := sha256.New() 26 out, err := os.Create(os.Args[1]) 27 if err != nil { 28 log.Fatal(err) 29 } 30 defer out.Close() 31 for _, filename := range os.Args[2:] { 32 f, err := os.Open(filename) 33 if err != nil { 34 log.Fatal(err) 35 } 36 defer f.Close() 37 if _, err := io.Copy(h, f); err != nil { 38 log.Fatal(err) 39 } 40 } 41 if _, err := out.Write(h.Sum(nil)); err != nil { 42 log.Fatal(err) 43 } 44} 45