=pod =head1 NAME BIO_new, BIO_set, BIO_free, BIO_vfree, BIO_free_all - BIO allocation and freeing functions =head1 SYNOPSIS #include 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); =head1 DESCRIPTION The BIO_new() function returns a new BIO using method B. 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. =head1 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. =head1 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 B 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_*(); =head1 EXAMPLE Create a memory BIO: BIO *mem = BIO_new(BIO_s_mem()); =head1 SEE ALSO TBA