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GETENTROPY(2) FreeBSD System Calls Manual GETENTROPY(2) 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(3). The maximum buffer size permitted is 256 bytes. getentropy() is not intended for regular code; please use the arc4random(3) family of functions instead. The high-quality entropy data is provided by the random(4) subsystem. 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. SEE ALSO arc4random(3) HISTORY The getentropy() function appeared in OpenBSD 5.6. FreeBSD 13.0 September 28, 2019 FreeBSD 13.0
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | HISTORY
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