Provided by: libssl-doc_1.0.2g-1ubuntu4.20_all 

NAME
RAND_load_file, RAND_write_file, RAND_file_name - PRNG seed file
SYNOPSIS
#include <openssl/rand.h>
const char *RAND_file_name(char *buf, size_t num);
int RAND_load_file(const char *filename, long max_bytes);
int RAND_write_file(const char *filename);
DESCRIPTION
RAND_file_name() generates a default path for the random seed file. buf points to a buffer of size num in
which to store the filename. The seed file is $RANDFILE if that environment variable is set, $HOME/.rnd
otherwise. If $HOME is not set either, or num is too small for the path name, an error occurs.
RAND_load_file() reads a number of bytes from file filename and adds them to the PRNG. If max_bytes is
non-negative, up to to max_bytes are read; starting with OpenSSL 0.9.5, if max_bytes is -1, the complete
file is read.
RAND_write_file() writes a number of random bytes (currently 1024) to file filename which can be used to
initialize the PRNG by calling RAND_load_file() in a later session.
RETURN VALUES
RAND_load_file() returns the number of bytes read.
RAND_write_file() returns the number of bytes written, and -1 if the bytes written were generated without
appropriate seed.
RAND_file_name() returns a pointer to buf on success, and NULL on error.
SEE ALSO
rand(3), RAND_add(3), RAND_cleanup(3)
HISTORY
RAND_load_file(), RAND_write_file() and RAND_file_name() are available in all versions of SSLeay and
OpenSSL.
1.0.2g 2016-03-01 RAND_load_file(3SSL)