| =pod |
| |
| =head1 NAME |
| |
| BIO_s_fd, BIO_set_fd, BIO_get_fd, BIO_new_fd - file descriptor BIO |
| |
| =head1 SYNOPSIS |
| |
| #include <openssl/bio.h> |
| |
| const BIO_METHOD *BIO_s_fd(void); |
| |
| int BIO_set_fd(BIO *b, int fd, int c); |
| int BIO_get_fd(BIO *b, int *c); |
| |
| BIO *BIO_new_fd(int fd, int close_flag); |
| |
| =head1 DESCRIPTION |
| |
| BIO_s_fd() returns the file descriptor BIO method. This is a wrapper |
| round the platforms file descriptor routines such as read() and write(). |
| |
| BIO_read_ex() and BIO_write_ex() read or write the underlying descriptor. |
| BIO_puts() is supported but BIO_gets() is not. |
| |
| If the close flag is set then close() is called on the underlying |
| file descriptor when the BIO is freed. |
| |
| BIO_reset() attempts to change the file pointer to the start of file |
| such as by using B<lseek(fd, 0, 0)>. |
| |
| BIO_seek() sets the file pointer to position B<ofs> from start of file |
| such as by using B<lseek(fd, ofs, 0)>. |
| |
| BIO_tell() returns the current file position such as by calling |
| B<lseek(fd, 0, 1)>. |
| |
| BIO_set_fd() sets the file descriptor of BIO B<b> to B<fd> and the close |
| flag to B<c>. |
| |
| BIO_get_fd() places the file descriptor in B<c> if it is not NULL, it also |
| returns the file descriptor. |
| |
| BIO_new_fd() returns a file descriptor BIO using B<fd> and B<close_flag>. |
| |
| =head1 NOTES |
| |
| The behaviour of BIO_read_ex() and BIO_write_ex() depends on the behavior of the |
| platforms read() and write() calls on the descriptor. If the underlying |
| file descriptor is in a non blocking mode then the BIO will behave in the |
| manner described in the L<BIO_read_ex(3)> and L<BIO_should_retry(3)> |
| manual pages. |
| |
| File descriptor BIOs should not be used for socket I/O. Use socket BIOs |
| instead. |
| |
| BIO_set_fd() and BIO_get_fd() are implemented as macros. |
| |
| =head1 RETURN VALUES |
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| BIO_s_fd() returns the file descriptor BIO method. |
| |
| BIO_set_fd() always returns 1. |
| |
| BIO_get_fd() returns the file descriptor or -1 if the BIO has not |
| been initialized. |
| |
| BIO_new_fd() returns the newly allocated BIO or NULL is an error |
| occurred. |
| |
| =head1 EXAMPLES |
| |
| This is a file descriptor BIO version of "Hello World": |
| |
| BIO *out; |
| |
| out = BIO_new_fd(fileno(stdout), BIO_NOCLOSE); |
| BIO_printf(out, "Hello World\n"); |
| BIO_free(out); |
| |
| =head1 SEE ALSO |
| |
| L<BIO_seek(3)>, L<BIO_tell(3)>, |
| L<BIO_reset(3)>, L<BIO_read_ex(3)>, |
| L<BIO_write_ex(3)>, L<BIO_puts(3)>, |
| L<BIO_gets(3)>, L<BIO_printf(3)>, |
| L<BIO_set_close(3)>, L<BIO_get_close(3)> |
| |
| =head1 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 |
| L<https://www.openssl.org/source/license.html>. |
| |
| =cut |
