GETENTROPY(3C) Standard C Library Functions GETENTROPY(3C)

NAME

getentropy - get entropy

SYNOPSIS

#include <unistd.h>

int
getentropy(void *buf, size_t buflen);

DESCRIPTION

getentropy fills a buffer with high-quality entropy, which can be used as
input for process-context pseudorandom generators like arc4random(3C).

The maximum buffer size permitted is 256 bytes. If buflen exceeds this, an
error of EIO will be indicated.

getentropy is not intended for regular code; please use the arc4random(3C)
family of functions instead.

RETURN VALUES

Upon successful completion, the value 0 is returned; otherwise the value -1
is returned and the global variable errno is set to indicate the error.

ERRORS

getentropy() will succeed unless:

EFAULT The buf parameter points to an invalid address.

EIO Too many bytes requested, or some other fatal error
occurred.

INTERFACE STABILITY

Comitted

MT-LEVEL
Async-Signal-Safe

SEE ALSO

arc4random(3C), attributes(7)

OmniOS December 31, 2014 OmniOS