Linux Certif

Toute la documentation sur la certification Linux LPI

splice

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splice - ¥Ñ¥¤¥×¤È¤Î´Ö¤Ç¥Ç¡¼¥¿¤ò·Ñ¤®¹ç¤ï¤»¤ë

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#define _GNU_SOURCE

#include <fcntl.h>



long splice(int fd_in, off_t *off_in, int fd_out,

            off_t *off_out, size_t len, unsigned int flags);

ÀâÌÀ

splice() ¤Ï¡¢¥«¡¼¥Í¥ë¥¢¥É¥ì¥¹¶õ´Ö¤È¥æ¡¼¥¶¥¢¥É¥ì¥¹¶õ´Ö¤È¤Î´Ö¤Î¥³¥Ô¡¼¤òȼ¤ï¤º¤Ë¡¢ 2 ¤Ä¤Î¥Õ¥¡¥¤¥ë¥Ç¥£¥¹¥¯¥ê¥×¥¿´Ö¤Ç¥Ç¡¼¥¿¤Î°ÜÆ°¤ò¹Ô¤¦¡£ ¥Õ¥¡¥¤¥ë¥Ç¥£¥¹¥¯¥ê¥×¥¿ fd_in ¤«¤é¥Õ¥¡¥¤¥ë¥Ç¥£¥¹¥¯¥ê¥×¥¿ fd_out ¤ØºÇÂç len ¥Ð¥¤¥È¤òžÁ÷¤¹¤ë¡£ 2 ¤Ä¤Î¥Õ¥¡¥¤¥ë¥Ç¥£¥¹¥¯¥ê¥×¥¿¤Î¤¦¤Á°ì¤Ä¤Ï ¥Ñ¥¤¥×¤ò»²¾È¤·¤Æ¤¤¤Ê¤±¤ì¤Ð¤Ê¤é¤Ê¤¤¡£

fd_in ¤¬¥Ñ¥¤¥×¤ò»²¾È¤·¤Æ¤¤¤ë¾ì¹ç¡¢ off_in ¤Ï NULL ¤Ç¤Ê¤±¤ì¤Ð¤Ê¤é¤Ê¤¤¡£ fd_in ¤¬¥Ñ¥¤¥×¤ò»²¾È¤·¤Æ¤ª¤é¤º¡¢ off_in ¤¬ NULL ¤Î¾ì¹ç¡¢ fd_in ¤Î¸½ºß¤Î¥Õ¥¡¥¤¥ë¥ª¥Õ¥»¥Ã¥È¤«¤é»Ï¤Þ¤ë¥Ð¥¤¥È¤òÆɤ߽Ф¹¡£ ¸½ºß¤Î¥Õ¥¡¥¤¥ë¥ª¥Õ¥»¥Ã¥È¤ÏŬÀÚ¤ËÄ´À°¤µ¤ì¤ë¡£ fd_in ¤¬¥Ñ¥¤¥×¤ò»²¾È¤·¤Æ¤ª¤é¤º¡¢ off_in ¤¬ NULL ¤Ç¤Ê¤¤¾ì¹ç¡¢ off_in ¤Ï fd_in ¤«¤é¤Î¥Ç¡¼¥¿Æɤ߽Ф·¤ò³«»Ï¤¹¤ëÀèƬ¥ª¥Õ¥»¥Ã¥È¤ò³ÊǼ¤·¤¿¥Ð¥Ã¥Õ¥¡ ¤Ø¤Î¥Ý¥¤¥ó¥¿¤Ç¤Ê¤±¤ì¤Ð¤Ê¤é¤Ê¤¤¡£¤³¤Î¾ì¹ç¡¢ fd_in ¤Î¸½ºß¤Î¥Õ¥¡¥¤¥ë¥ª¥Õ¥»¥Ã¥È¤ÏÊѹ¹¤µ¤ì¤Ê¤¤¡£ fd_out ¤È off_out ¤Ë´Ø¤·¤Æ¤âƱÍͤǤ¢¤ë¡£

flags °ú¤­¿ô¤Ë¤Ï¡¢°Ê²¼¤ÎÃͤΠ0 ¸Ä°Ê¾å¤Î¥Ó¥Ã¥Èñ°Ì¤ÎÏÀÍýϤò ¤È¤Ã¤¿¤â¤Î¤ò»ØÄꤹ¤ë:

SPLICE_F_MOVE

¥Ú¡¼¥¸¤Î¥³¥Ô¡¼¤Ç¤Ê¤¯°ÜÆ°¤ò»î¤ß¤ë¡£ ¤³¤ì¤Ï¥«¡¼¥Í¥ë¤ËÂФ¹¤ë¥Ò¥ó¥È¤Ç¤·¤«¤Ê¤¤¡£ ¤Ä¤Þ¤ê¡¢¥«¡¼¥Í¥ë¤¬¥Ñ¥¤¥×¤«¤é¥Ú¡¼¥¸¤ò°ÜÆ°¤Ç¤­¤Ê¤¤¾ì¹ç¤ä¡¢ ¥Ñ¥¤¥×¥Ð¥Ã¥Õ¥¡¤¬¥Ú¡¼¥¸Á´Éô¤ò»²¾È¤·¤Æ¤¤¤Ê¤¤¾ì¹ç¤Ï¡¢ ¥Ú¡¼¥¸¤Î¥³¥Ô¡¼¤¬¹Ô¤ï¤ì¤ë¤³¤È¤â¤¢¤ë¡£

SPLICE_F_NONBLOCK

Æþ½ÐÎÏ»þ¤ËÄä»ß (block) ¤·¤Ê¤¤¡£ ¤³¤Î¥Õ¥é¥°¤ò»ØÄꤹ¤ë¤È¡¢ splice ¤Ë¤è¤ë¥Ñ¥¤¥×Áàºî¤òÈóÄä»ß¥â¡¼¥É (non-blocking) ¤Ç ¹Ô¤ª¤¦¤È¤¹¤ë¤¬¡¢¤½¤Î¾ì¹ç¤Ç¤â splice() ¤ÏÄä»ß¤¹¤ë¤³¤È¤â¤¢¤ë¡£¤Ê¤¼¤Ê¤é¡¢¥Ç¡¼¥¿¤Î¤ä¤ê¼è¤ê¤ò¹Ô¤¦ ¥Õ¥¡¥¤¥ë¥Ç¥£¥¹¥¯¥ê¥×¥¿¤Ï (O_NONBLOCK ¥Õ¥é¥°¤ò¥»¥Ã¥È¤µ¤ì¤Æ¤¤¤Ê¤¤¾ì¹ç) Ää»ß¤¹¤ë²ÄǽÀ­¤¬¤¢¤ë¤«¤é¤Ç¤¢¤ë¡£

SPLICE_F_MORE

¤³¤Î¸å¤Î splice ¤Ç¤µ¤é¤ËžÁ÷¤µ¤ì¤ë¥Ç¡¼¥¿¤¬¤¢¤ë¤³¤È¤ò¼¨¤¹¡£ ¤³¤Î¥Õ¥é¥°¤Ï fd_out ¤¬¥½¥±¥Ã¥È¤ò»²¾È¤·¤Æ¤¤¤ë¾ì¹ç¤ËÍ­ÍѤʥҥó¥È¤È¤Ê¤ë (send(2) ¤Î MSG_MORE ¤ä tcp(7) ¤Î TCP_CORK ¤ÎÀâÌÀ¤â»²¾È)¡£

SPLICE_F_GIFT

splice() ¤Ç¤Ï»ÈÍѤ·¤Ê¤¤¡£ vmsplice(2) »²¾È¡£

ÊÖ¤êÃÍ

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¥¨¥é¡¼¤Î¾ì¹ç¡¢ splice() ¤Ï -1 ¤òÊÖ¤·¡¢ errno ¤Ë¥¨¥é¡¼¤ò¼¨¤¹ÃͤòÀßÄꤹ¤ë¡£

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EBADF

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EINVAL

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ENOMEM

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ESPIPE

off_in ¤« off_out ¤Î¤¤¤º¤ì¤«¤¬ NULL ¤Ç¤Ï¤Ê¤¤¤¬¡¢Âбþ¤¹¤ë¥Õ¥¡¥¤¥ë¥Ç¥£¥¹¥¯¥ê¥×¥¿¤¬ ¥Ñ¥¤¥×¤ò»²¾È¤·¤Æ¤¤¤ë¡£

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splice(2) ¥·¥¹¥Æ¥à¥³¡¼¥ë¤Ï Linux 2.6.17 ¤Ç½é¤á¤ÆÅо줷¤¿¡£

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3 ¤Ä¤Î¥·¥¹¥Æ¥à¥³¡¼¥ë (splice(2), vmsplice(2), tee(2)) ¤ò»È¤¦¤È¡¢¥æ¡¼¥¶¶õ´Ö¥×¥í¥°¥é¥à¤ÏǤ°Õ¤Î¥«¡¼¥Í¥ë¥Ð¥Ã¥Õ¥¡¤ËÂФ¹¤ë ´°Á´¤ÊÀ©¸æ¤¬¤Ç¤­¤ë¡£¥«¡¼¥Í¥ë¥Ð¥Ã¥Õ¥¡¤Ï¡¢¥Ñ¥¤¥×¤Ë»ÈÍѤµ¤ì¤Æ¤¤¤ë¤Î¤È Ʊ¼ï¤Î¥Ð¥Ã¥Õ¥¡¤ò»È¤Ã¤Æ¥«¡¼¥Í¥ëÆâ¤Ë¼ÂÁõ¤µ¤ì¤Æ¤¤¤ë¡£ Âç¤Þ¤«¤Ë¤¤¤¦¤È¡¢¤³¤ì¤é¤Î¥·¥¹¥Æ¥à¥³¡¼¥ë¤Ï°Ê²¼¤Î»Å»ö¤ò¹Ô¤¦:

splice()

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tee(2)

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vmsplice(2)

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tee(2) »²¾È¡£

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sendfile(2), splice(2), tee(2), feature_test_macros(7)