=pod

=head1 NAME

 BIO_ctrl_get_read_request - Find out how much bytes are were requested from the BIO

=head1 SYNOPSIS

 #include <openssl/bio.h>

 size_t BIO_ctrl_get_read_request(BIO *bio);

=head1 DESCRIPTION

BIO_ctrl_get_read_request() returns the number of bytes that were last
requested from B<bio> by a BIO_read() operation. This is useful e.g. for
BIO pairs, so that the application knows how much bytes to supply to B<bio>.

=head1 BUGS

When B<bio> is NULL, the OpenSSL library calls assert().

=head1 RETURN VALUES

The following return values can occur:

=over 4

=item E<gt>=0

The number of bytes requested.

=back

=head1 SEE ALSO

L<bio(3)|bio(3)>, L<BIO_s_mem(3)|BIO_s_mem(3)>,
L<BIO_new_bio_pair(3)|BIO_new_bio_pair(3)>