BIO_s_null(3)

BIO_s_null(3) | OpenSSL | BIO_s_null(3)

# 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 Apache License 2.0 (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>.

2026-06-09 | 3.5.7