.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" This manpage is Copyright (C) 2006 Jens Axboe
.\" and Copyright (C) 2006 Michael Kerrisk <mtk.manpages@gmail.com>
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.\" Japanese Version Copyright (c) 2007  Akihiro MOTOKI
.\"         all rights reserved.
.\" Translated 2007-02-04, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\" 
.TH SPLICE 2 2008-01-31 "Linux" "Linux Programmer's Manual"
.SH ̾
splice \- ѥפȤδ֤ǥǡѤ碌
.SH 
.nf
.B #define _GNU_SOURCE
.B #include <fcntl.h>

.BI "long splice(int " fd_in ", loff_t *" off_in ", int " fd_out ,
.BI "            loff_t *" off_out ", size_t " len \
", unsigned int " flags );
.fi
.SH 
.BR splice ()
ϡͥ륢ɥ쥹֤ȥ桼ɥ쥹֤Ȥδ֤Υԡȼ鷺ˡ
2 ĤΥեǥץ֤ǥǡΰưԤ
եǥץ
.I fd_in
եǥץ
.I fd_out
غ
.I len
ХȤž롣
2 ĤΥեǥץΤĤ
ѥפ򻲾ȤƤʤФʤʤ
.PP
.I fd_in
ѥפ򻲾ȤƤ硢
.I off_in
 NULL ǤʤФʤʤ
.I fd_in
ѥפ򻲾ȤƤ餺
.I off_in
 NULL ξ硢
.I fd_in
θߤΥե륪եåȤϤޤХȤɤ߽Ф
ߤΥե륪եåȤŬڤĴ롣
.I fd_in
ѥפ򻲾ȤƤ餺
.I off_in
 NULL Ǥʤ硢
.I off_in

.I fd_in
Υǡɤ߽Ф򳫻ϤƬեåȤǼХåե
ؤΥݥ󥿤ǤʤФʤʤξ硢
.I fd_in
θߤΥե륪եåȤѹʤ
.I fd_out

.I off_out
˴ؤƤƱͤǤ롣
.PP
.I flags
ˤϡʲͤ 0 İʾΥӥåñ̤¤
ȤäΤꤹ:
.TP 1.9i
.B SPLICE_F_MOVE
ڡΥԡǤʤưߤ롣
ϥͥФҥȤǤʤ
Ĥޤꡢͥ뤬ѥפڡưǤʤ䡢
ѥץХåեڡ򻲾ȤƤʤϡ
ڡΥԡԤ뤳Ȥ⤢롣
.TP
.B SPLICE_F_NONBLOCK
ϻ (block) ʤ
Υե饰ꤹȡ
splice ˤѥߥ⡼ (non-blocking) 
ԤȤ뤬ξǤ
.BR splice ()
ߤ뤳Ȥ⤢롣ʤʤ顢ǡΤԤ
եǥץ
.RB ( O_NONBLOCK
ե饰򥻥åȤƤʤ) ߤǽ뤫Ǥ롣
.TP
.B SPLICE_F_MORE
θ splice Ǥžǡ뤳Ȥ򼨤
Υե饰
.I fd_out
åȤ򻲾ȤƤͭѤʥҥȤȤʤ
.RB ( send (2)

.B MSG_MORE

.BR tcp (7)

.B TCP_CORK
⻲)
.TP
.B SPLICE_F_GIFT
.BR splice ()
ǤϻѤʤ
.BR vmsplice (2)
ȡ
.SH ֤
ƴλȡ
.BR splice ()
ϥѥפФ줷Хȿ֤
֤ 0 ϥǡžԤʤäȤ򼨤
ξ硢 (block) Ƥ̵̣Ǥ롣
ʤʤ顢
.I fd_in
Ȥѥפν񤭹¦³ƤԤʤǤ롣
.PP
顼ξ硢
.BR splice ()
 \-1 ֤
.I errno
˥顼򼨤ͤꤹ롣
.SH 顼
.TP
.B EBADF
եǥץΰޤξͭǤϤʤ
⤷Ŭڤ read-write ⡼ɤǤϤʤ
.TP
.B EINVAL
оݤΥե륷ƥब splice бƤʤ
ޤϥǥץΤɤѥפ򻲾ȤƤʤ
ޤ seek ǤʤǥХФƥեåȤꤵ줿
.TP
.B ENOMEM
­
.TP
.B ESPIPE
.I off_in

.I off_out
Τ줫 NULL ǤϤʤбեǥץ
ѥפ򻲾ȤƤ롣
.SH С
.BR splice ()
ƥॳ Linux 2.6.17 ǽо줷
.SH 
Υƥॳ Linux ͭǤ롣
.SH 
3 ĤΥƥॳ
.RB ( splice (),
.BR vmsplice (2),
.BR tee (2))
Ȥȡ桼֥ץǤդΥͥХåեФ
椬Ǥ롣ͥХåեϡѥפ˻ѤƤΤ
ƱΥХåեȤäƥͥ˼Ƥ롣
ޤˤȡΥƥॳϰʲλŻԤ:
.TP 1.2i
.BR splice ()
ХåեǤդΥեǥץ䡢ε
⤷ϤХåե̤ΥХåեؤΡǡưԤ
.TP
.BR tee (2)
Хåե̤ΥХåեؤΥǡ֥ԡפԤ
.TP
.BR vmsplice (2)
桼֤ХåեؤΥǡ֥ԡפԤ
.PP
Ǥϥԡä򤷤Ƥ뤬ºݤΥԡϰŪ˲򤵤롣
ͥϡѥסХåե򥫡ͥΥڡؤΥݥ󥿽Ȥ
ڡؤλȲ뤳Ȥǡ¸Ƥ롣
ͥϡоݤȤʤڡ򻲾Ȥ (ϥХåեѤ) ݥ󥿤
˺뤳ȤǥХåեΥڡΡ֥ԡפ
ΥڡλȲ䤹Ĥޤꡢݥ󥿤ԡ졢
ХåեΥڡϥԡʤ
.\"
.\" Linus: Now, imagine using the above in a media server, for example.
.\" Let's say that a year or two has passed, so that the video drivers
.\" have been updated to be able to do the splice thing, and what can
.\" you do? You can:
.\"
.\" - splice from the (mpeg or whatever - let's just assume that the video
.\"   input is either digital or does the encoding on its own - like they
.\"   pretty much all do) video input into a pipe (remember: no copies - the
.\"   video input will just DMA directly into memory, and splice will just
.\"   set up the pages in the pipe buffer)
.\" - tee that pipe to split it up
.\" - splice one end to a file (ie "save the compressed stream to disk")
.\" - splice the other end to a real-time video decoder window for your
.\"   real-time viewing pleasure.
.\"
.\" Linus: Now, the advantage of splice()/tee() is that you can
.\" do zero-copy movement of data, and unlike sendfile() you can
.\" do it on _arbitrary_ data (and, as shown by "tee()", it's more
.\" than just sending the data to somebody else: you can duplicate
.\" the data and choose to forward it to two or more different
.\" users - for things like logging etc.).
.\"
.SH 
.BR tee (2)
ȡ
.SH Ϣ
.BR sendfile (2),
.BR tee (2),
.BR vmsplice (2),
.BR feature_test_macros (7)