1=pod 2 3=head1 NAME 4 5BIO_find_type, BIO_next, BIO_method_type - BIO chain traversal 6 7=head1 SYNOPSIS 8 9 #include <openssl/bio.h> 10 11 BIO *BIO_find_type(BIO *b, int bio_type); 12 BIO *BIO_next(BIO *b); 13 int BIO_method_type(const BIO *b); 14 15=head1 DESCRIPTION 16 17The BIO_find_type() searches for a B<BIO> of a given type in a chain, starting 18at B<BIO> I<b>. If I<type> is a specific type (such as B<BIO_TYPE_MEM>) then a 19search is made for a B<BIO> of that type. If I<type> is a general type (such as 20B<BIO_TYPE_SOURCE_SINK>) then the next matching B<BIO> of the given general type is 21searched for. BIO_find_type() returns the next matching B<BIO> or NULL if none is 22found. If I<type> is B<BIO_TYPE_NONE> it will not find a match. 23 24The following general types are defined: 25B<BIO_TYPE_DESCRIPTOR>, B<BIO_TYPE_FILTER>, and B<BIO_TYPE_SOURCE_SINK>. 26 27For a list of the specific types, see the F<< <openssl/bio.h> >> header file. 28 29BIO_next() returns the next BIO in a chain. It can be used to traverse all BIOs 30in a chain or used in conjunction with BIO_find_type() to find all BIOs of a 31certain type. 32 33BIO_method_type() returns the type of a BIO. 34 35=head1 RETURN VALUES 36 37BIO_find_type() returns a matching BIO or NULL for no match. 38 39BIO_next() returns the next BIO in a chain. 40 41BIO_method_type() returns the type of the BIO I<b>. 42 43=head1 EXAMPLES 44 45Traverse a chain looking for digest BIOs: 46 47 BIO *btmp; 48 49 btmp = in_bio; /* in_bio is chain to search through */ 50 do { 51 btmp = BIO_find_type(btmp, BIO_TYPE_MD); 52 if (btmp == NULL) 53 break; /* Not found */ 54 /* btmp is a digest BIO, do something with it ...*/ 55 ... 56 57 btmp = BIO_next(btmp); 58 } while (btmp); 59 60 61=head1 COPYRIGHT 62 63Copyright 2000-2024 The OpenSSL Project Authors. All Rights Reserved. 64 65Licensed under the Apache License 2.0 (the "License"). You may not use 66this file except in compliance with the License. You can obtain a copy 67in the file LICENSE in the source distribution or at 68L<https://www.openssl.org/source/license.html>. 69 70=cut 71
