{ "mode": "man", "parameter": "bio", "section": "7ssl", "url": "https://www.chedong.com/phpMan.php/man/bio/7ssl/json", "generated": "2026-07-05T13:02:18Z", "synopsis": "#include ", "sections": { "NAME": { "content": "bio - Basic I/O abstraction\n", "subsections": [] }, "SYNOPSIS": { "content": "#include \n", "subsections": [] }, "DESCRIPTION": { "content": "A BIO is an I/O abstraction, it hides many of the underlying I/O details from an application.\nIf an application uses a BIO for its I/O it can transparently handle SSL connections,\nunencrypted network connections and file I/O.\n\nThere are two types of BIO, a source/sink BIO and a filter BIO.\n\nAs its name implies a source/sink BIO is a source and/or sink of data, examples include a\nsocket BIO and a file BIO.\n\nA filter BIO takes data from one BIO and passes it through to another, or the application.\nThe data may be left unmodified (for example a message digest BIO) or translated (for example\nan encryption BIO). The effect of a filter BIO may change according to the I/O operation it\nis performing: for example an encryption BIO will encrypt data if it is being written to and\ndecrypt data if it is being read from.\n\nBIOs can be joined together to form a chain (a single BIO is a chain with one component). A\nchain normally consists of one source/sink BIO and one or more filter BIOs. Data read from or\nwritten to the first BIO then traverses the chain to the end (normally a source/sink BIO).\n\nSome BIOs (such as memory BIOs) can be used immediately after calling BIOnew(). Others (such\nas file BIOs) need some additional initialization, and frequently a utility function exists\nto create and initialize such BIOs.\n\nIf BIOfree() is called on a BIO chain it will only free one BIO resulting in a memory leak.\n\nCalling BIOfreeall() on a single BIO has the same effect as calling BIOfree() on it other\nthan the discarded return value.\n\nNormally the type argument is supplied by a function which returns a pointer to a BIOMETHOD.\nThere is a naming convention for such functions: a source/sink BIO typically starts with\nBIOs and a filter BIO with BIOf.\n", "subsections": [] }, "EXAMPLES": { "content": "Create a memory BIO:\n\nBIO *mem = BIOnew(BIOsmem());\n", "subsections": [] }, "SEE ALSO": { "content": "BIOctrl(3), BIOfbase64(3), BIOfbuffer(3), BIOfcipher(3), BIOfmd(3), BIOfnull(3),\nBIOfssl(3), BIOfreadbuffer(3), BIOfindtype(3), BIOnew(3), BIOnewbiopair(3),\nBIOpush(3), BIOreadex(3), BIOsaccept(3), BIOsbio(3), BIOsconnect(3), BIOsfd(3),\nBIOsfile(3), BIOsmem(3), BIOsnull(3), BIOssocket(3), BIOsetcallback(3),\nBIOshouldretry(3)\n", "subsections": [] }, "COPYRIGHT": { "content": "Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.\n\nLicensed under the Apache License 2.0 (the \"License\"). You may not use this file except in\ncompliance with the License. You can obtain a copy in the file LICENSE in the source\ndistribution or at .\n\n\n\n3.0.2 2026-06-02 BIO(7SSL)", "subsections": [] } }, "summary": "bio - Basic I/O abstraction", "flags": [], "examples": [ "Create a memory BIO:", "BIO *mem = BIOnew(BIOsmem());" ], "see_also": [ { "name": "BIOctrl", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOctrl/3/json" }, { "name": "BIOfbase64", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOfbase64/3/json" }, { "name": "BIOfbuffer", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOfbuffer/3/json" }, { "name": "BIOfcipher", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOfcipher/3/json" }, { "name": "BIOfmd", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOfmd/3/json" }, { "name": "BIOfnull", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOfnull/3/json" }, { "name": "BIOfssl", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOfssl/3/json" }, { "name": "BIOfreadbuffer", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOfreadbuffer/3/json" }, { "name": "BIOfindtype", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOfindtype/3/json" }, { "name": "BIOnew", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOnew/3/json" }, { "name": "BIOnewbiopair", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOnewbiopair/3/json" }, { "name": "BIOpush", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOpush/3/json" }, { "name": "BIOreadex", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOreadex/3/json" }, { "name": "BIOsaccept", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOsaccept/3/json" }, { "name": "BIOsbio", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOsbio/3/json" }, { "name": "BIOsconnect", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOsconnect/3/json" }, { "name": "BIOsfd", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOsfd/3/json" }, { "name": "BIOsfile", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOsfile/3/json" }, { "name": "BIOsmem", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOsmem/3/json" }, { "name": "BIOsnull", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOsnull/3/json" }, { "name": "BIOssocket", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOssocket/3/json" }, { "name": "BIOsetcallback", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOsetcallback/3/json" }, { "name": "BIOshouldretry", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/BIOshouldretry/3/json" } ] }