- NAME
- SYNOPSIS
- DESCRIPTION
- RETURN VALUES
- NOTES
- HISTORY
- EXAMPLES
- COPYRIGHT

# NAME

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

# SYNOPSIS

     #include <openssl/bio.h>

     BIO *  BIO_new(const BIO_METHOD *type);
     int    BIO_up_ref(BIO *a);
     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_up_ref()` increments the reference count associated with the BIO object.

`BIO_free()` frees up a single BIO, `BIO_vfree()` also frees up a single BIO but it does not return a value. If a is NULL nothing is done. 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. If a is NULL nothing is done.

# RETURN VALUES

`BIO_new()` returns a newly created BIO or NULL if the call fails.

`BIO_up_ref()` and `BIO_free()` return 1 for success and 0 for failure.

`BIO_free_all()` and `BIO_vfree()` do not return values.

# NOTES

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.

# HISTORY

`BIO_set()` was removed in OpenSSL 1.1.0 as BIO type is now opaque.

# EXAMPLES

Create a memory BIO:

     BIO *mem = BIO_new(BIO_s_mem());

# COPYRIGHT

Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at https://www.openssl.org/source/license.html.