mirror of
https://github.com/openssl/openssl.git
synced 2024-12-16 13:33:49 +08:00
90 lines
2.7 KiB
Plaintext
90 lines
2.7 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
BIO_s_fd, BIO_set_fd, BIO_get_fd, BIO_new_fd - file descriptor BIO
|
|
|
|
=head1 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);
|
|
|
|
=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() 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 B<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<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. If B<c> is not NULL it should be of type
|
|
(int *).
|
|
|
|
BIO_new_fd() returns a file descriptor BIO using B<fd> and B<close_flag>.
|
|
|
|
=head1 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 L<BIO_read(3)|BIO_read(3)> and L<BIO_should_retry(3)|BIO_should_retry(3)>
|
|
manual pages.
|
|
|
|
File descriptor BIOs should not be used for socket I/O. Use socket BIOs
|
|
instead.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
BIO_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.
|
|
|
|
=head1 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);
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<BIO_seek(3)|BIO_seek(3)>, L<BIO_tell(3)|BIO_tell(3)>,
|
|
L<BIO_reset(3)|BIO_reset(3)>, L<BIO_read(3)|BIO_read(3)>,
|
|
L<BIO_write(3)|BIO_write(3)>, L<BIO_puts(3)|BIO_puts(3)>,
|
|
L<BIO_gets(3)|BIO_gets(3)>, L<BIO_printf(3)|BIO_printf(3)>,
|
|
L<BIO_set_close(3)|BIO_set_close(3)>, L<BIO_get_close(3)|BIO_get_close(3)>
|