| 1 | =pod
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| 2 |
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| 3 | =head1 NAME
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| 4 |
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| 5 | BIO_s_fd, BIO_set_fd, BIO_get_fd, BIO_new_fd - file descriptor BIO
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| 6 |
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| 7 | =head1 SYNOPSIS
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| 8 |
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| 9 | #include <openssl/bio.h>
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| 10 |
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| 11 | const BIO_METHOD *BIO_s_fd(void);
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| 12 |
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| 13 | int BIO_set_fd(BIO *b, int fd, int c);
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| 14 | int BIO_get_fd(BIO *b, int *c);
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| 15 |
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| 16 | BIO *BIO_new_fd(int fd, int close_flag);
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| 17 |
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| 18 | =head1 DESCRIPTION
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| 19 |
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| 20 | BIO_s_fd() returns the file descriptor BIO method. This is a wrapper
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| 21 | round the platforms file descriptor routines such as read() and write().
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| 22 |
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| 23 | BIO_read_ex() and BIO_write_ex() read or write the underlying descriptor.
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| 24 | BIO_puts() is supported but BIO_gets() is not.
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| 25 |
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| 26 | If the close flag is set then close() is called on the underlying
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| 27 | file descriptor when the BIO is freed.
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| 28 |
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| 29 | BIO_reset() attempts to change the file pointer to the start of file
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| 30 | such as by using B<lseek(fd, 0, 0)>.
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| 31 |
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| 32 | BIO_seek() sets the file pointer to position B<ofs> from start of file
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| 33 | such as by using B<lseek(fd, ofs, 0)>.
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| 34 |
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| 35 | BIO_tell() returns the current file position such as by calling
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| 36 | B<lseek(fd, 0, 1)>.
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| 37 |
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| 38 | BIO_set_fd() sets the file descriptor of BIO B<b> to B<fd> and the close
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| 39 | flag to B<c>.
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| 40 |
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| 41 | BIO_get_fd() places the file descriptor in B<c> if it is not NULL, it also
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| 42 | returns the file descriptor.
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| 43 |
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| 44 | BIO_new_fd() returns a file descriptor BIO using B<fd> and B<close_flag>.
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| 45 |
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| 46 | =head1 NOTES
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| 47 |
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| 48 | The behaviour of BIO_read_ex() and BIO_write_ex() depends on the behavior of the
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| 49 | platforms read() and write() calls on the descriptor. If the underlying
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| 50 | file descriptor is in a non blocking mode then the BIO will behave in the
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| 51 | manner described in the L<BIO_read_ex(3)> and L<BIO_should_retry(3)>
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| 52 | manual pages.
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| 53 |
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| 54 | File descriptor BIOs should not be used for socket I/O. Use socket BIOs
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| 55 | instead.
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| 56 |
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| 57 | BIO_set_fd() and BIO_get_fd() are implemented as macros.
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| 58 |
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| 59 | =head1 RETURN VALUES
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| 60 |
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| 61 | BIO_s_fd() returns the file descriptor BIO method.
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| 62 |
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| 63 | BIO_set_fd() always returns 1.
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| 64 |
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| 65 | BIO_get_fd() returns the file descriptor or -1 if the BIO has not
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| 66 | been initialized.
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| 67 |
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| 68 | BIO_new_fd() returns the newly allocated BIO or NULL is an error
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| 69 | occurred.
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| 70 |
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| 71 | =head1 EXAMPLES
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| 72 |
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| 73 | This is a file descriptor BIO version of "Hello World":
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| 74 |
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| 75 | BIO *out;
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| 76 |
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| 77 | out = BIO_new_fd(fileno(stdout), BIO_NOCLOSE);
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| 78 | BIO_printf(out, "Hello World\n");
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| 79 | BIO_free(out);
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| 80 |
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| 81 | =head1 SEE ALSO
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| 82 |
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| 83 | L<BIO_seek(3)>, L<BIO_tell(3)>,
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| 84 | L<BIO_reset(3)>, L<BIO_read_ex(3)>,
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| 85 | L<BIO_write_ex(3)>, L<BIO_puts(3)>,
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| 86 | L<BIO_gets(3)>, L<BIO_printf(3)>,
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| 87 | L<BIO_set_close(3)>, L<BIO_get_close(3)>
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| 88 |
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| 89 | =head1 COPYRIGHT
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| 90 |
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| 91 | Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
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| 92 |
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| 93 | Licensed under the OpenSSL license (the "License"). You may not use
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| 94 | this file except in compliance with the License. You can obtain a copy
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| 95 | in the file LICENSE in the source distribution or at
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| 96 | L<https://www.openssl.org/source/license.html>.
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| 97 |
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| 98 | =cut
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