MultiChecksum

MultiChecksum is a go module and a commandline application to generate multiple cryptographic checksums at once for a given set of files.

Variants

There are different variants available, the key differences are described below.

Library Variant

There is a very simple library called multichecksum. It consists out of one function and one type.

// Checksums is a map that holds filename and checksums for that file
type Checksums map[string]string

// CalcChecksums takes a filename and the file content and returns a map with the checksums
func CalcChecksums(filename string, data []byte) *Checksums {
    [...] }

The command line tool makes use of that library as you can see in the following listing:

        [...]
		chksums := multichecksum.CalcChecksums(filename, data)
		for _, sum := range *chksums {
			fmt.Printf("%s", sum)
		}
        [...]

Stand Alone Variant

The stand alone variant is under cmd/MultiChecksumNoLib/. This is a command line tool that does the job, no library required.

This is basically the first version of MultiChecksum

BigData Variant

There is also a BigData variant, under cmd/MultiChecksumBigData/. The BigData variant is different from the above variants in the following ways:

• it does not load the whole data to checksum into memory, instead it streams the data.
• it starts a worker for each given file to calculate the checksums.

Fetch

go get github.com/scusi/MultiChecksum

Install

# Install the lib
cd ${GOPATH}/src/github.com/scusi/MultiChecksum
go install

# Install the commandline app
cd ${GOPATH}/src/github.com/scusi/MultiChecksum/cmd/MultiChecksum/
go install MultiChecksum.go

Run

After installing the commandline app you should be able to execute

MultiChecksum file1.bin file2.bin anotherFile.doc