=pod

=head1 NAME

BIO_s_null - null data sink

=head1 SYNOPSIS

 #include <openssl/bio.h>

 BIO_METHOD *	BIO_s_null(void);

=head1 DESCRIPTION

BIO_s_null() returns the null sink BIO method. Data written to
the null sink is discarded, reads return EOF.

=head1 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

=head1 RETURN VALUES

BIO_s_null() returns the null sink BIO method.

=head1 SEE ALSO

TBA