5 BIO_new, BIO_set, BIO_up_ref, BIO_free, BIO_vfree, BIO_free_all - BIO allocation and freeing functions
9 #include <openssl/bio.h>
11 BIO * BIO_new(const BIO_METHOD *type);
12 int BIO_set(BIO *a,const BIO_METHOD *type);
13 int BIO_up_ref(BIO *a);
15 void BIO_vfree(BIO *a);
16 void BIO_free_all(BIO *a);
20 The BIO_new() function returns a new BIO using method B<type>.
22 BIO_set() sets the method of an already existing BIO.
24 BIO_up_ref() increments the reference count associated with the BIO object.
26 BIO_free() frees up a single BIO, BIO_vfree() also frees up a single BIO
27 but it does not return a value.
28 If B<a> is NULL nothing is done.
29 Calling BIO_free() may also have some effect
30 on the underlying I/O structure, for example it may close the file being
31 referred to under certain circumstances. For more details see the individual
32 BIO_METHOD descriptions.
34 BIO_free_all() frees up an entire BIO chain, it does not halt if an error
35 occurs freeing up an individual BIO in the chain.
36 If B<a> is NULL nothing is done.
40 BIO_new() returns a newly created BIO or NULL if the call fails.
42 BIO_set(), BIO_up_ref() and BIO_free() return 1 for success and 0 for failure.
44 BIO_free_all() and BIO_vfree() do not return values.
48 Some BIOs (such as memory BIOs) can be used immediately after calling
49 BIO_new(). Others (such as file BIOs) need some additional initialization,
50 and frequently a utility function exists to create and initialize such BIOs.
52 If BIO_free() is called on a BIO chain it will only free one BIO resulting
55 Calling BIO_free_all() a single BIO has the same effect as calling BIO_free()
56 on it other than the discarded return value.
58 Normally the B<type> argument is supplied by a function which returns a
59 pointer to a BIO_METHOD. There is a naming convention for such functions:
60 a source/sink BIO is normally called BIO_s_*() and a filter BIO
67 BIO *mem = BIO_new(BIO_s_mem());