5 BIO_s_fd - file descriptor BIO
9 #include <openssl/bio.h>
11 BIO_METHOD * BIO_s_fd(void);
13 #define BIO_seek(b,ofs) (int)BIO_ctrl(b,BIO_C_FILE_SEEK,ofs,NULL)
14 #define BIO_tell(b) (int)BIO_ctrl(b,BIO_C_FILE_TELL,0,NULL)
16 #define BIO_set_fd(b,fd,c) BIO_int_ctrl(b,BIO_C_SET_FD,c,fd)
17 #define BIO_get_fd(b,c) BIO_ctrl(b,BIO_C_GET_FD,0,(char *)c)
19 BIO *BIO_new_fd(int fd, int close_flag);
23 BIO_s_fd() returns the file descriptor BIO method. This is a wrapper
24 round the platforms file descriptor routines such as read() and write().
26 BIO_read() and BIO_write() read or write the underlying descriptor.
27 BIO_puts() is supported but BIO_gets() is not.
29 If the close flag is set then then close() is called on the underlying
30 file descriptor when the BIO is freed.
32 BIO_reset() attempts to change the file pointer to the start of file
33 using lseek(fd, 0, 0).
35 BIO_seek() sets the file pointer to position B<ofs> from start of file
36 using lseek(fd, ofs, 0).
38 BIO_tell() returns the current file position by calling lseek(fd, 0, 1).
40 BIO_set_fd() sets the file descriptor of BIO B<b> to B<fd> and the close
43 BIO_get_fd() places the file descriptor in B<c> if it is not NULL, it also
44 returns the file descriptor. If B<c> is not NULL it should be of type
47 BIO_new_fd() returns a file desciptor BIO using B<fd> and B<close_flag>.
51 The behaviour of BIO_read() and BIO_write() depends on the behaviour of the
52 platforms read() and write() calls on the descriptor. If the underlying
53 file descriptor is in a non blocking mode then the BIO will behave in the
54 manner described in the L<BIO_read(3)|BIO_read(3)> and L<BIO_should_retry(3)|BIO_should_retry(3)>
57 File descriptor BIOs should not be used for socket I/O. Use socket BIOs
62 BIO_s_fd() returns the file descriptor BIO method.
64 BIO_reset() returns zero for success and -1 if an error occurred.
65 BIO_seek() and BIO_tell() return the current file position or -1
66 is an error occurred. These values reflect the underlying lseek()
69 BIO_set_fd() always returns 1.
71 BIO_get_fd() returns the file descriptor or -1 if the BIO has not
74 BIO_new_fd() returns the newly allocated BIO or NULL is an error
79 This is a file descriptor BIO version of "Hello World":
82 out = BIO_new_fd(fileno(stdout), BIO_NOCLOSE);
83 BIO_printf(out, "Hello World\n");