gazelle/manifest/hasher/main.go

// Copyright 2023 The Bazel Authors. All rights reserved.
//
// 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.

package main

import (
	"crypto/sha256"
	"io"
	"log"
	"os"
)

func main() {
	h := sha256.New()
	out, err := os.Create(os.Args[1])
	if err != nil {
		log.Fatal(err)
	}
	defer out.Close()
	for _, filename := range os.Args[2:] {
		f, err := os.Open(filename)
		if err != nil {
			log.Fatal(err)
		}
		defer f.Close()
		if _, err := io.Copy(h, f); err != nil {
			log.Fatal(err)
		}
	}
	if _, err := out.Write(h.Sum(nil)); err != nil {
		log.Fatal(err)
	}
}