52 lines
1.7 KiB
Text
52 lines
1.7 KiB
Text
=pod
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=head1 NAME
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BIO_read, BIO_write, BIO_gets, BIO_puts - BIO I/O functions
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=head1 SYNOPSIS
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#include <openssl/bio.h>
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int BIO_read(BIO *b, void *buf, int len);
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int BIO_gets(BIO *b,char *buf, int size);
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int BIO_write(BIO *b, const void *buf, int len);
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int BIO_puts(BIO *b,const char *buf);
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=head1 DESCRIPTION
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BIO_read() attempts to read B<len> bytes from BIO B<b> and places
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the data in B<buf>.
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BIO_gets() performs the BIOs "gets" operation and places the data
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in B<buf>. Usually this operation will attempt to read a line of data
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from the BIO of maximum length B<len>. There are exceptions to this
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however, for example BIO_gets() on a digest BIO will calculate and
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return the digest and other BIOs may not support BIO_gets() at all.
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BIO_write() attempts to write B<len> bytes from B<buf> to BIO B<b>.
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BIO_puts() attempts to write a null terminated string B<buf> to BIO B<b>
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=head1 RETURN VALUES
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All these functions return either the amount of data successfully read or
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written (if the return value is positive) or that no data was successfully
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read or written (if the result is zero or negative).
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=head1 NOTES
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A negative or zero return is not necessarily an indication of an error. In
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particular when the source/sink is non-blocking or of a certain type (for
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example an SSL BIO can retry even if the underlying connection is blocking)
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it may merely be an indication that no data is currently available and that
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the application should retry the operation later. L<BIO_should_retry(3)|BIO_should_retry(3)>
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can be called to determine the precise cause.
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If the BIO_gets() function is not supported by a BIO then it possible to
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work around this by adding a buffering BIO L<BIO_f_buffer(3)|BIO_f_buffer(3)>
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to the chain.
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=head1 SEE ALSO
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TBA
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