BIO_S_NULL(3)              Library Functions Manual              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.

     A null sink BIO behaves in a similar manner to the null(4) 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.

     When called on a null sink BIO object, BIO_method_type(3) returns the
     constant BIO_TYPE_NULL and BIO_method_name(3) returns a pointer to the
     static string "NULL", not to be confused with a NUL string nor with a
     NULL pointer.

SEE ALSO
     BIO_new(3)

HISTORY
     BIO_s_null() first appeared in SSLeay 0.6.0 and has been available since
     OpenBSD 2.4.

Linux 6.8.7-arch1-1             April 11, 2023             Linux 6.8.7-arch1-1