BIO_next

BIO_find_type(3)		   OpenSSL		     BIO_find_type(3)



NAME
       BIO_find_type, BIO_next - BIO chain traversal

SYNOPSIS
	#include <openssl/bio.h>

	BIO *  BIO_find_type(BIO *b,int bio_type);
	BIO *  BIO_next(BIO *b);

	#define BIO_method_type(b)	       ((b)->method->type)

	#define BIO_TYPE_NONE	       0
	#define BIO_TYPE_MEM	       (1│0x0400)
	#define BIO_TYPE_FILE	       (2│0x0400)

	#define BIO_TYPE_FD	       (4│0x0400│0x0100)
	#define BIO_TYPE_SOCKET		       (5│0x0400│0x0100)
	#define BIO_TYPE_NULL	       (6│0x0400)
	#define BIO_TYPE_SSL	       (7│0x0200)
	#define BIO_TYPE_MD	       (8│0x0200)
	#define BIO_TYPE_BUFFER		       (9│0x0200)
	#define BIO_TYPE_CIPHER		       (10│0x0200)
	#define BIO_TYPE_BASE64		       (11│0x0200)
	#define BIO_TYPE_CONNECT       (12│0x0400│0x0100)
	#define BIO_TYPE_ACCEPT		       (13│0x0400│0x0100)
	#define BIO_TYPE_PROXY_CLIENT  (14│0x0200)
	#define BIO_TYPE_PROXY_SERVER  (15│0x0200)
	#define BIO_TYPE_NBIO_TEST     (16│0x0200)
	#define BIO_TYPE_NULL_FILTER   (17│0x0200)
	#define BIO_TYPE_BER	       (18│0x0200)
	#define BIO_TYPE_BIO	       (19│0x0400)

	#define BIO_TYPE_DESCRIPTOR    0x0100
	#define BIO_TYPE_FILTER		       0x0200
	#define BIO_TYPE_SOURCE_SINK   0x0400

DESCRIPTION
       The BIO_find_type() searches for a BIO of a given type in a chain,
       starting at BIO b. If type is a specific type (such as BIO_TYPE_MEM)
       then a search is made for a BIO of that type. If type is a general
       type (such as 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.

       Note: not all the BIO_TYPE_* types above have corresponding BIO imple-
       mentations.

       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.

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.

NOTES
       BIO_next() was added to OpenSSL 0.9.6 to provide a ’clean’ way to tra-
       verse a BIO chain or find multiple matches using BIO_find_type().
       Previous versions had to use:

	next = bio->next_bio;

BUGS
       BIO_find_type() in OpenSSL 0.9.5a and earlier could not be safely
       passed a NULL pointer for the b argument.

EXAMPLE
       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);

SEE ALSO
       TBA



0.9.7a				  2000-09-14		     BIO_find_type(3)