1/* Interfaces for obtaining random bytes.
2 Copyright (C) 2016-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef _SYS_RANDOM_H
20#define _SYS_RANDOM_H 1
21
22#include <features.h>
23#include <sys/types.h>
24
25/* Flags for use with getrandom. */
26#define GRND_NONBLOCK 0x01
27#define GRND_RANDOM 0x02
28#define GRND_INSECURE 0x04
29
30__BEGIN_DECLS
31
32/* Write LENGTH bytes of randomness starting at BUFFER. Return the
33 number of bytes written, or -1 on error. */
34ssize_t getrandom (void *__buffer, size_t __length,
35 unsigned int __flags) __wur;
36
37/* Write LENGTH bytes of randomness starting at BUFFER. Return 0 on
38 success or -1 on error. */
39int getentropy (void *__buffer, size_t __length) __wur;
40
41__END_DECLS
42
43#endif /* _SYS_RANDOM_H */
44

source code of glibc/stdlib/sys/random.h