package rand

Import Path
	crypto/rand (on go.dev)

Dependency Relation
	imports 12 packages, and imported by 8 packages

Involved Source Files

	  d rand.go
		Package rand implements a cryptographically secure
		random number generator.

	    rand_getrandom.go
	    rand_unix.go
	    util.go
Code Examples

	Read
		package main
		
		import (
			"bytes"
			"crypto/rand"
			"fmt"
		)
		
		func main() {
			c := 10
			b := make([]byte, c)
			_, err := rand.Read(b)
			if err != nil {
				fmt.Println("error:", err)
				return
			}
			// The slice should now contain random bytes instead of only zeroes.
			fmt.Println(bytes.Equal(b, make([]byte, c)))
		
		}


Package-Level Type Names (total 2, neither is exported)

	/* sort exporteds by: alphabet | popularity */
	/* 2 unexporteds ... *//* 2 unexporteds: */
	 type hideAgainReader (struct)
		hideAgainReader masks EAGAIN reads from /dev/urandom.
		See golang.org/issue/9205

		Fields (only one, which is unexported)
			/* one unexported ... *//* one unexported: */
			r io.Reader
		Methods (only one, which is exported)
			( hideAgainReader) Read(p []byte) (n int, err error)
		Implements (at least one exported)
			 hideAgainReader : io.Reader

	 type reader (struct)
		A reader satisfies reads by reading from urandomDevice

		Fields (total 3, none are exported)
			/* 3 unexporteds ... *//* 3 unexporteds: */
			f io.Reader
			mu sync.Mutex
			used atomic.Uint32
				// Atomic: 0 - never used, 1 - used, but f == nil, 2 - used, and f != nil

		Methods (only one, which is exported)
			(*reader) Read(b []byte) (n int, err error)
		Implements (at least one exported)
			*reader : io.Reader


Package-Level Functions (total 8, in which 3 are exported)

	 func Int(rand io.Reader, max *big.Int) (n *big.Int, err error)
		Int returns a uniform random value in [0, max). It panics if max <= 0.

	 func Prime(rand io.Reader, bits int) (*big.Int, error)
		Prime returns a number of the given bit length that is prime with high probability.
		Prime will return error for any error returned by rand.Read or if bits < 2.

	 func Read(b []byte) (n int, err error)
		Read is a helper function that calls Reader.Read using io.ReadFull.
		On return, n == len(b) if and only if err == nil.

	/* 5 unexporteds ... *//* 5 unexporteds: */
	 func batched(f func([]byte) error, readMax int) func([]byte) error
		batched returns a function that calls f to populate a []byte by chunking it
		into subslices of, at most, readMax bytes.

	 func getRandom(p []byte) error
		If the kernel is too old to support the getrandom syscall(),
		unix.GetRandom will immediately return ENOSYS and we will then fall back to
		reading from /dev/urandom in rand_unix.go. unix.GetRandom caches the ENOSYS
		result so we only suffer the syscall overhead once in this case.
		If the kernel supports the getrandom() syscall, unix.GetRandom will block
		until the kernel has sufficient randomness (as we don't use GRND_NONBLOCK).
		In this case, unix.GetRandom will not return an error.

	 func init()
	 func init()
	 func warnBlocked()
Package-Level Variables (total 2, in which 1 is exported)

	  var Reader io.Reader
		Reader is a global, shared instance of a cryptographically
		secure random number generator.
		
		On Linux, FreeBSD, Dragonfly, NetBSD and Solaris, Reader uses getrandom(2) if
		available, /dev/urandom otherwise.
		On OpenBSD and macOS, Reader uses getentropy(2).
		On other Unix-like systems, Reader reads from /dev/urandom.
		On Windows systems, Reader uses the ProcessPrng API.
		On JS/Wasm, Reader uses the Web Crypto API.
		On WASIP1/Wasm, Reader uses random_get from wasi_snapshot_preview1.

	/* one unexported ... *//* one unexported: */
	  var altGetRandom ([]byte) (err error)
		altGetRandom if non-nil specifies an OS-specific function to get
		urandom-style randomness.


Package-Level Constants (only one, which is unexported)

	/* one unexported ... *//* one unexported: */
	const urandomDevice = "/dev/urandom"

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