NAME

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

SYNOPSIS

        #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

       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

       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

       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

       Create a memory BIO:

        BIO *mem = BIO_new(BIO_s_mem());

SEE ALSO

       TBA