openssl/doc/man3/BIO_find_type.pod

71 lines
1.9 KiB
Plaintext
Raw Normal View History

2023-05-09 22:08:48 +00:00
=pod
=head1 NAME
BIO_find_type, BIO_next, BIO_method_type - BIO chain traversal
=head1 SYNOPSIS
#include <openssl/bio.h>
BIO *BIO_find_type(BIO *b, int bio_type);
BIO *BIO_next(BIO *b);
int BIO_method_type(const BIO *b);
=head1 DESCRIPTION
The BIO_find_type() searches for a BIO of a given type in a chain, starting
at BIO B<b>. If B<type> is a specific type (such as B<BIO_TYPE_MEM>) then a search
is made for a BIO of that type. If B<type> is a general type (such as
B<BIO_TYPE_SOURCE_SINK>) then the next matching BIO of the given general type is
searched for. BIO_find_type() returns the next matching BIO or NULL if none is
found.
The following general types are defined:
B<BIO_TYPE_DESCRIPTOR>, B<BIO_TYPE_FILTER>, and B<BIO_TYPE_SOURCE_SINK>.
For a list of the specific types, see the B<openssl/bio.h> header file.
BIO_next() returns the next BIO in a chain. It can be used to traverse all BIOs
in a chain or used in conjunction with BIO_find_type() to find all BIOs of a
certain type.
BIO_method_type() returns the type of a BIO.
=head1 RETURN VALUES
BIO_find_type() returns a matching BIO or NULL for no match.
BIO_next() returns the next BIO in a chain.
BIO_method_type() returns the type of the BIO B<b>.
=head1 EXAMPLES
Traverse a chain looking for digest BIOs:
BIO *btmp;
btmp = in_bio; /* in_bio is chain to search through */
do {
btmp = BIO_find_type(btmp, BIO_TYPE_MD);
if (btmp == NULL)
break; /* Not found */
/* btmp is a digest BIO, do something with it ...*/
...
btmp = BIO_next(btmp);
} while (btmp);
=head1 COPYRIGHT
Copyright 2000-2019 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
L<https://www.openssl.org/source/license.html>.
=cut