BIO_s_fd(3) OpenSSL BIO_s_fd(3)NAME
BIO_s_fd, BIO_set_fd, BIO_get_fd, BIO_new_fd - file
descriptor BIO
SYNOPSIS
#include <openssl/bio.h>
BIO_METHOD * BIO_s_fd(void);
#define BIO_set_fd(b,fd,c) BIO_int_ctrl(b,BIO_C_SET_FD,c,fd)
#define BIO_get_fd(b,c) BIO_ctrl(b,BIO_C_GET_FD,0,(char *)c)
BIO *BIO_new_fd(int fd, int close_flag);
DESCRIPTIONBIO_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() and BIO_write() read or write the underlying
descriptor. BIO_puts() is supported but BIO_gets() is
not.
If the close flag is set then 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 using lseek(fd, 0, 0).
BIO_seek() sets the file pointer to position ofs from
start of file using lseek(fd, ofs, 0).
BIO_tell() returns the current file position 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. If c is not
NULL it should be of type (int *).
BIO_new_fd() returns a file descriptor BIO using fd and
close_flag.
NOTES
The behaviour of BIO_read() and BIO_write() 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(3) and BIO_should_retry(3)
manual pages.
File descriptor BIOs should not be used for socket I/O.
Use socket BIOs instead.
RETURN VALUESBIO_s_fd() returns the file descriptor BIO method.
BIO_reset() returns zero for success and -1 if an error
occurred. BIO_seek() and BIO_tell() return the current
file position or -1 is an error occurred. These values
reflect the underlying lseek() behaviour.
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.
EXAMPLE
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);
SEE ALSOBIO_seek(3), BIO_tell(3), BIO_reset(3), BIO_read(3),
BIO_write(3), BIO_puts(3), BIO_gets(3), BIO_printf(3),
BIO_set_close(3), BIO_get_close(3)17/Sep/2000 0.9.6j BIO_s_fd(3)
