BIO_new, BIO_set, BIO_free, BIO_vfree, BIO_free_all - BIO allocation and freeing
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);
function returns a new BIO using method type
sets the method of an already existing BIO.
frees up a single BIO, BIO_vfree()
also frees up a
single BIO but it does not return a value. Calling BIO_free()
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.
frees up an entire BIO chain, it does not halt if an error
occurs freeing up an individual BIO in the chain.
returns a newly created BIO or NULL if the call fails.
return 1 for success and 0 for failure.
do not return values.
Some BIOs (such as memory BIOs) can be used immediately after calling
. Others (such as file BIOs) need some additional
initialization, and frequently a utility function exists to create and
initialize such BIOs.
is called on a BIO chain it will only free one BIO
resulting in a memory leak.
a single BIO has the same effect as calling
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_*();
Create a memory BIO:
BIO *mem = BIO_new(BIO_s_mem());