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.. .nr rF 0 . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF Fear. Run. Save yourself. No user-serviceable parts.
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Title "BIO_CTRL 3ossl"
way too many mistakes in technical documents.
\fBBIO_reset() typically resets a \s-1BIO\s0 to some initial state, in the case of file related BIOs for example it rewinds the file pointer to the start of the file.
\fBBIO_seek() resets a file related \s-1BIO\s0's (that is file descriptor and \s-1FILE\s0 BIOs) file position pointer to ofs bytes from start of file.
\fBBIO_tell() returns the current file position of a file related \s-1BIO.\s0
\fBBIO_flush() normally writes out any internally buffered data, in some cases it is used to signal \s-1EOF\s0 and that no more data will be written.
\fBBIO_eof() returns 1 if the \s-1BIO\s0 has read \s-1EOF,\s0 the precise meaning of \*(L"\s-1EOF\*(R"\s0 varies according to the \s-1BIO\s0 type.
\fBBIO_set_close() sets the \s-1BIO\s0 b close flag to flag. flag can take the value \s-1BIO_CLOSE\s0 or \s-1BIO_NOCLOSE.\s0 Typically \s-1BIO_CLOSE\s0 is used in a source/sink \s-1BIO\s0 to indicate that the underlying I/O stream should be closed when the \s-1BIO\s0 is freed.
\fBBIO_get_close() returns the BIOs close flag.
\fBBIO_pending(), BIO_ctrl_pending(), BIO_wpending() and BIO_ctrl_wpending() return the number of pending characters in the BIOs read and write buffers. Not all BIOs support these calls. BIO_ctrl_pending() and BIO_ctrl_wpending() return a size_t type and are functions, BIO_pending() and BIO_wpending() are macros which call BIO_ctrl().
\fBBIO_get_ktls_send() returns 1 if the \s-1BIO\s0 is using the Kernel \s-1TLS\s0 data-path for sending. Otherwise, it returns zero. \fBBIO_get_ktls_recv() returns 1 if the \s-1BIO\s0 is using the Kernel \s-1TLS\s0 data-path for receiving. Otherwise, it returns zero.
\fBBIO_seek() and BIO_tell() both return the current file position on success and -1 for failure, except file BIOs which for BIO_seek() always return 0 for success and -1 for failure.
\fBBIO_flush() returns 1 for success and <=0 for failure.
\fBBIO_eof() returns 1 if \s-1EOF\s0 has been reached, 0 if not, or negative values for failure.
\fBBIO_set_close() returns 1 on success or <=0 for failure.
\fBBIO_get_close() returns the close flag value: \s-1BIO_CLOSE\s0 or \s-1BIO_NOCLOSE.\s0 It also returns other negative values if an error occurs.
\fBBIO_pending(), BIO_ctrl_pending(), BIO_wpending() and BIO_ctrl_wpending() return the amount of pending data. BIO_pending() and BIO_wpending() return negative value or 0 on error. BIO_ctrl_pending() and BIO_ctrl_wpending() return 0 on error.
\fBBIO_get_ktls_send() returns 1 if the \s-1BIO\s0 is using the Kernel \s-1TLS\s0 data-path for sending. Otherwise, it returns zero. \fBBIO_get_ktls_recv() returns 1 if the \s-1BIO\s0 is using the Kernel \s-1TLS\s0 data-path for receiving. Otherwise, it returns zero.
The return values of BIO_pending() and BIO_wpending() may not reliably determine the amount of pending data in all cases. For example in the case of a file \s-1BIO\s0 some data may be available in the \s-1FILE\s0 structures internal buffers but it is not possible to determine this in a portably way. For other types of \s-1BIO\s0 they may not be supported.
Filter BIOs if they do not internally handle a particular BIO_ctrl() operation usually pass the operation to the next \s-1BIO\s0 in the chain. This often means there is no need to locate the required \s-1BIO\s0 for a particular operation, it can be called on a chain and it will be automatically passed to the relevant \s-1BIO.\s0 However, this can cause unexpected results: for example no current filter BIOs implement \fBBIO_seek(), but this may still succeed if the chain ends in a \s-1FILE\s0 or file descriptor \s-1BIO.\s0
Source/sink BIOs return an 0 if they do not recognize the BIO_ctrl() operation.
In older versions of OpenSSL the BIO_ctrl_pending() and \fBBIO_ctrl_wpending() could return values greater than \s-1INT_MAX\s0 on error.
Licensed under the Apache License 2.0 (the \*(L"License\*(R"). You may not use this file except in compliance with the License. You can obtain a copy in the file \s-1LICENSE\s0 in the source distribution or at <https://www.openssl.org/source/license.html>.