GETENTROPY(2) | System Calls Manual | GETENTROPY(2) |
getentropy
— get
entropy
#include
<unistd.h>
int
getentropy
(void
*buf, size_t
buflen);
getentropy
()
fills a buffer with high-quality entropy, which can be used as input for
process-context pseudorandom generators like
arc4random(3).
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(3) family of
functions instead.
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.
getentropy
() will succeed unless:
The getentropy
() function appeared in
OpenBSD 5.6.
January 31, 2015 | OpenBSD-6.4 |