BIO_find_type(3)

     BIO_find_type(3)       0.9.6h (2000-09-14)       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 implementations.

          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.

     Page 1                                         (printed 1/19/103)

     BIO_find_type(3)       0.9.6h (2000-09-14)       BIO_find_type(3)

          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 traverse 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

     Page 2                                         (printed 1/19/103)