NAME    [Toc]    [Back]

       BIO_new, BIO_set, BIO_free, BIO_vfree, BIO_free_all - BIO
       allocation and freeing functions

LIBRARY    [Toc]    [Back]

       libcrypto, -lcrypto

SYNOPSIS    [Toc]    [Back]

        #include <openssl/bio.h>

        BIO *  BIO_new(BIO_METHOD *type);
        int    BIO_set(BIO *a,BIO_METHOD *type);
        int    BIO_free(BIO *a);
        void   BIO_vfree(BIO *a);
        void   BIO_free_all(BIO *a);

DESCRIPTION    [Toc]    [Back]

       The BIO_new() function returns a new BIO using method
       type.

       BIO_set() sets the method of an already existing BIO.

       BIO_free() frees up a single BIO, BIO_vfree() also frees
       up a single BIO but it does not return a value. Calling
       BIO_free() may also have some effect on the underlying I/O
       structure, for example it may close the file being
       referred to under certain circumstances. For more details
       see the individual BIO_METHOD descriptions.

       BIO_free_all() frees up an entire BIO chain, it does not
       halt if an error occurs freeing up an individual BIO in
       the chain.

RETURN VALUES    [Toc]    [Back]

       BIO_new() returns a newly created BIO or NULL if the call
       fails.

       BIO_set(), BIO_free() return 1 for success and 0 for failure.


       BIO_free_all() and BIO_vfree() do not return values.

NOTES    [Toc]    [Back]

       Some BIOs (such as memory BIOs) can be used immediately
       after calling BIO_new(). Others (such as file BIOs) need
       some additional initialization, and frequently a utility
       function exists to create and initialize such BIOs.

       If BIO_free() is called on a BIO chain it will only free
       one BIO resulting in a memory leak.

       Calling BIO_free_all() a single BIO has the same effect as
       calling BIO_free() on it other than the discarded return
       value.

       Normally the type argument is supplied by a function which
       returns a pointer to a BIO_METHOD. There is a naming convention
 for such functions: a source/sink BIO is normally
       called BIO_s_*() and a filter BIO BIO_f_*();

EXAMPLE    [Toc]    [Back]

       Create a memory BIO:

        BIO *mem = BIO_new(BIO_s_mem());

SEE ALSO    [Toc]    [Back]

       TBA



2001-04-12                    0.9.6g                   BIO_new(3)