BIO_s_fd(3) OpenSSL BIO_s_fd(3) NNAAMMEE BIO_s_fd, BIO_set_fd, BIO_get_fd, BIO_new_fd - file descriptor BIO SSYYNNOOPPSSIISS #include 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); DDEESSCCRRIIPPTTIIOONN _B_I_O___s___f_d_(_) returns the file descriptor BIO method. This is a wrapper round the platforms file descriptor routines such as _r_e_a_d_(_) and _w_r_i_t_e_(_). _B_I_O___r_e_a_d_(_) and _B_I_O___w_r_i_t_e_(_) read or write the underlying descriptor. _B_I_O___p_u_t_s_(_) is supported but _B_I_O___g_e_t_s_(_) is not. If the close flag is set then then _c_l_o_s_e_(_) is called on the underlying file descriptor when the BIO is freed. _B_I_O___r_e_s_e_t_(_) attempts to change the file pointer to the start of file using lseek(fd, 0, 0). _B_I_O___s_e_e_k_(_) sets the file pointer to position ooffss from start of file using lseek(fd, ofs, 0). _B_I_O___t_e_l_l_(_) returns the current file position by calling lseek(fd, 0, 1). _B_I_O___s_e_t___f_d_(_) sets the file descriptor of BIO bb to ffdd and the close flag to cc. _B_I_O___g_e_t___f_d_(_) places the file descriptor in cc if it is not NULL, it also returns the file descriptor. If cc is not NULL it should be of type (int *). _B_I_O___n_e_w___f_d_(_) returns a file descriptor BIO using ffdd and cclloossee__ffllaagg. NNOOTTEESS The behaviour of _B_I_O___r_e_a_d_(_) and _B_I_O___w_r_i_t_e_(_) depends on the behavior of the platforms _r_e_a_d_(_) and _w_r_i_t_e_(_) calls on the descriptor. If the under- lying file descriptor is in a non blocking mode then the BIO will behave in the manner described in the _B_I_O___r_e_a_d(3) and _B_I_O___s_h_o_u_l_d___r_e_t_r_y(3) manual pages. File descriptor BIOs should not be used for socket I/O. Use socket BIOs instead. RREETTUURRNN VVAALLUUEESS _B_I_O___s___f_d_(_) returns the file descriptor BIO method. _B_I_O___r_e_s_e_t_(_) returns zero for success and -1 if an error occurred. _B_I_O___s_e_e_k_(_) and _B_I_O___t_e_l_l_(_) return the current file position or -1 if an error occurred. These values reflect the underlying _l_s_e_e_k_(_) behaviour. _B_I_O___s_e_t___f_d_(_) always returns 1. _B_I_O___g_e_t___f_d_(_) returns the file descriptor or -1 if the BIO has not been initialized. _B_I_O___n_e_w___f_d_(_) returns the newly allocated BIO or NULL is an error occurred. EEXXAAMMPPLLEE 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); SSEEEE AALLSSOO _B_I_O___s_e_e_k(3), _B_I_O___t_e_l_l(3), _B_I_O___r_e_s_e_t(3), _B_I_O___r_e_a_d(3), _B_I_O___w_r_i_t_e(3), _B_I_O___p_u_t_s(3), _B_I_O___g_e_t_s(3), _B_I_O___p_r_i_n_t_f(3), _B_I_O___s_e_t___c_l_o_s_e(3), _B_I_O___g_e_t___c_l_o_s_e(3) 1.0.2u 2019-12-20 BIO_s_fd(3)