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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() function 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 sought. The BIO_find_type()function returns the next matching BIO or
  NULL if none is found.

				     Note

       Some BIO_TYPE_* types do not have corresponding BIO implementations.

  The BIO_next()function returns the next BIO in a chain. It can be used to
  traverse all BIOs in a chain or used in conjunction with the
  BIO_find_type() function to find all BIOs of a certain type.

  The BIO_method_type() function returns the type of a BIO.

NOTES
  The BIO_next() function was added to OpenSSL 0.9.6 to provide a clean way
  to traverse a BIO chain or find multiple matches using the BIO_find_type()
  function. Previous versions used the following:

	next = bio->next_bio;

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

RETURN VALUES
  The BIO_find_type() function returns a matching BIO or NULL for no match.

  The BIO_next() function returns the next BIO in a chain.

  The BIO_method_type() function returns the type of the BIO b.

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

Index for Section 3

Alphabetical listing for B

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