Provided by: libssl-doc_1.1.1-1ubuntu2.1~18.04.23_all 
NAME
BIO_s_null - null data sink
SYNOPSIS
#include <openssl/bio.h>
const BIO_METHOD *BIO_s_null(void);
DESCRIPTION
BIO_s_null() returns the null sink BIO method. Data written to the null sink is discarded, reads return
EOF.
NOTES
A null sink BIO behaves in a similar manner to the Unix /dev/null device.
A null bio can be placed on the end of a chain to discard any data passed through it.
A null sink is useful if, for example, an application wishes to digest some data by writing through a
digest bio but not send the digested data anywhere. Since a BIO chain must normally include a
source/sink BIO this can be achieved by adding a null sink BIO to the end of the chain
RETURN VALUES
BIO_s_null() returns the null sink BIO method.
COPYRIGHT
Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You may not use this file except in compliance with
the License. You can obtain a copy in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.