Prints crc32c hashes in the same format as Google Cloud storage

crc32c.go

// Prints CRC32C hashes in the same format as Google Cloud Storage
//
// Usage: crc32c (paths to hash)
// See also: gsutil hash
package main

import (
	"encoding/base64"
	"encoding/hex"
	"fmt"
	"hash/crc32"
	"io"
	"os"
)

var crc32cTable = crc32.MakeTable(crc32.Castagnoli)

func crc32c(r io.Reader) ([]byte, error) {
	hash := crc32.New(crc32cTable)
	_, err := io.Copy(hash, r)
	if err != nil {
		return nil, err
	}
	return hash.Sum(nil), nil
}

func main() {
	if len(os.Args) <= 1 {
		os.Args = append(os.Args, "-")
	}

	for _, path := range os.Args[1:] {
		var input *os.File
		var err error
		if path == "-" {
			input = os.Stdin
		} else {
			input, err = os.Open(path)
			if err != nil {
				panic(err)
			}
		}

		value, err := crc32c(input)
		err2 := input.Close()
		if err != nil {
			panic(err)
		}
		if err2 != nil {
			panic(err)
		}

		fmt.Printf("%s: base64:%s hex:%s\n", path,
			base64.StdEncoding.EncodeToString(value), hex.EncodeToString(value))
	}
}

Thanks!

Ha you are welcome, although I admit I no longer remember why this was useful to me at the time :)