| .\" Copyright (C) 2022 Jens Axboe <axboe@kernel.dk> |
| .\" |
| .\" SPDX-License-Identifier: LGPL-2.0-or-later |
| .\" |
| .TH io_uring_prep_tee 3 "March 13, 2022" "liburing-2.2" "liburing Manual" |
| .SH NAME |
| io_uring_prep_tee \- prepare a tee request |
| .SH SYNOPSIS |
| .nf |
| .B #include <fcntl.h> |
| .B #include <liburing.h> |
| .PP |
| .BI "void io_uring_prep_tee(struct io_uring_sqe *" sqe "," |
| .BI " int " fd_in "," |
| .BI " int " fd_out "," |
| .BI " unsigned int " nbytes "," |
| .BI " unsigned int " splice_flags ");" |
| .fi |
| .SH DESCRIPTION |
| .PP |
| The |
| .BR io_uring_prep_tee (3) |
| function prepares a tee request. The submission queue entry |
| .I sqe |
| is setup to use as input the file descriptor |
| .I fd_in |
| and as output the file descriptor |
| .I fd_out |
| duplicating |
| .I nbytes |
| bytes worth of data. |
| .I splice_flags |
| are modifier flags for the operation. See |
| .BR tee (2) |
| for the generic splice flags. |
| |
| If the |
| .I fd_out |
| descriptor, |
| .B IOSQE_FIXED_FILE |
| can be set in the SQE to indicate that. For the input file, the io_uring |
| specific |
| .B SPLICE_F_FD_IN_FIXED |
| can be set and |
| .I fd_in |
| given as a registered file descriptor offset. |
| |
| This function prepares an async |
| .BR tee (2) |
| request. See that man page for details. |
| |
| .SH RETURN VALUE |
| None |
| .SH ERRORS |
| The CQE |
| .I res |
| field will contain the result of the operation. See the related man page for |
| details on possible values. Note that where synchronous system calls will return |
| .B -1 |
| on failure and set |
| .I errno |
| to the actual error value, io_uring never uses |
| .IR errno . |
| Instead it returns the negated |
| .I errno |
| directly in the CQE |
| .I res |
| field. |
| .SH SEE ALSO |
| .BR io_uring_get_sqe (3), |
| .BR io_uring_submit (3), |
| .BR io_uring_register (2), |
| .BR splice (2), |
| .BR tee (2) |