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 2000-2019 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 https://www.openssl.org/source/license.html.