BIO_NEW(3) BSD Library Functions Manual BIO_NEW(3)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 VALUESBIO_new() returns a newly created BIO or NULL if the call fails.
BIO_set() and 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 initializa‐
tion, 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() on 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 func‐
tions: a source/sink BIO is normally called BIO_s_*() and a filter BIO
BIO_f_*().
EXAMPLES
Create a memory BIO:
BIO *mem = BIO_new(BIO_s_mem());
BSD July 17, 2014 BSD