src/crypto/rand/example_test.go

// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package rand_test

import (
	"crypto/rand"
	"fmt"
	"math/big"
)

// ExampleInt prints a single cryptographically secure pseudorandom number between 0 and 99 inclusive.
func ExampleInt() {
	// Int cannot return an error when using rand.Reader.
	a, _ := rand.Int(rand.Reader, big.NewInt(100))
	fmt.Println(a.Int64())
}

// ExamplePrime prints a cryptographically secure pseudorandom 64 bit prime number.
func ExamplePrime() {
	// Prime cannot return an error when using rand.Reader and bits >= 2.
	a, _ := rand.Prime(rand.Reader, 64)
	fmt.Println(a.Int64())
}

// ExampleRead prints a cryptographically secure pseudorandom 32 byte key.
func ExampleRead() {
	// Note that no error handling is necessary, as Read always succeeds.
	key := make([]byte, 32)
	rand.Read(key)
	// The key can contain any byte value, print the key in hex.
	fmt.Printf("% x\n", key)
}

// ExampleText prints a random key encoded in base32.
func ExampleText() {
	key := rand.Text()
	// The key is base32 and safe to display.
	fmt.Println(key)
}