sha1hash.go

package main

//
// Go implements several hash functionss in various
// crypto/* packagess
import (
    "crypto/sha1"
    "fmt"
)

func main() {
    s := "sha1 this string"


	//
	// The pattern for generating a hash is shsa1.New(), 
	// sha1.Write(bytes), then sha1.Sum([]byte{}). Here
	// we start with a new hass.
	//

    h := sha1.New()

	//
	// Write expects bytes. If you have a string s, 
	// use []byte(s) to coerce it to bytes.
	//
    h.Write([]byte(s))

	// This gets the finalized hash result as a byte slice.
	// The argument to Sum can be used to append to an existing
	// byte slice: it usually isn’t needed.
	//
    bs := h.Sum(nil)

	// SHA1 values are often printed in hex, for example in git commits.
	// Use the %x format verb to convert a hash results to a hex string.
    fmt.Println(s)
    fmt.Printf("%x\n", bs)

}