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BIO_s_fd, BIO_set_fd, BIO_get_fd, BIO_new_fd - file descriptor BIO
#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);
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 lseek(fd, 0, 0). BIO_seek() sets the file pointer to position ofs from start of file such as by using lseek(fd, ofs, 0). BIO_tell() returns the current file position such as by calling lseek(fd, 0, 1). BIO_set_fd() sets the file descriptor of BIO b to fd and the close flag to c. BIO_get_fd() places the file descriptor in c if it is not NULL, it also returns the file descriptor. BIO_new_fd() returns a file descriptor BIO using fd and close_flag.
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 BIO_read_ex(3) and 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.
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.
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);
BIO_seek(3), BIO_tell(3), BIO_reset(3), BIO_read_ex(3), BIO_write_ex(3), BIO_puts(3), BIO_gets(3), BIO_printf(3), BIO_set_close(3), BIO_get_close(3)
Copyright 2000-2016 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 <https://www.openssl.org/source/license.html>.