Linux Certif

Toute la documentation sur la certification Linux LPI

sem_open

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#include <semaphore.h>



sem_t *sem_open(const char *name, int oflag);

sem_t *sem_open(const char *name, int oflag, 

                mode_t mode, unsigned int value);

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oflag °ú¤­¿ô¤Ë¤Ï¡¢ sem_open() ¤ÎÆ°ºî¤òÀ©¸æ¤¹¤ë¥Õ¥é¥°¤ò»ØÄꤹ¤ë¡£ oflag ¤Ë O_CREAT ¤¬»ØÄꤵ¤ì¤ë¤È¡¢¤Þ¤À¸ºß¤·¤Ê¤¤¾ì¹ç¤Ë¤Ï¤½¤Î¥»¥Þ¥Õ¥©¤¬ºîÀ®¤µ¤ì¤ë¡£ ¥»¥Þ¥Õ¥©¤Î½êÍ­¼Ô (¥æ¡¼¥¶ ID)¡¢¥°¥ë¡¼¥×½êÍ­¸¢ (¥°¥ë¡¼¥× ID) ¤Ë¤Ï¡¢ ¤½¤ì¤¾¤ì¸Æ¤Ó½Ð¤·¸µ¥×¥í¥»¥¹¤Î¼Â¸ú UID¡¢¼Â¸ú GID ¤¬ÀßÄꤵ¤ì¤ë¡£ oflag ¤Ë O_CREAT ¤È O_EXCL ¤ÎξÊý¤¬»ØÄꤵ¤ì¤¿¾ì¹ç¡¢»ØÄꤵ¤ì¤¿Ì¾Á° name ¤Î¥»¥Þ¥Õ¥©¤¬¤¹¤Ç¤Ë¸ºß¤¹¤ë¤È¥¨¥é¡¼¤¬ÊÖ¤µ¤ì¤ë¡£

oflag ¤Ë O_CREAT ¤ò»ØÄꤹ¤ë¾ì¹ç¡¢¤µ¤é¤Ë°ú¤­¿ô¤¬ 2 ¤ÄɬÍפǤ¢¤ë¡£ mode °ú¤­¿ô¤Ï¡¢ open(2) ¤ÈƱ¤¸¤è¤¦¤Ë¡¢¿·¤·¤¤¥»¥Þ¥Õ¥©¤ËÀßÄꤵ¤ì¤ë¥¢¥¯¥»¥¹µö²Ä (permission) ¤ò »ØÄꤹ¤ë¡£µö²ÄÀßÄê¤Ï¥×¥í¥»¥¹¤Î umask ¤Ç¥Þ¥¹¥¯¤µ¤ì¤ë¡£ ¥»¥Þ¥Õ¥©¤Ë¥¢¥¯¥»¥¹¤·¤è¤¦¤È¤¹¤ë¥æ¡¼¥¶¤Ï¡¢Æɤ߽Ф·µö²Ä¤È½ñ¤­¹þ¤ßµö²Ä¤Î ξÊý¤òÆÀ¤ëɬÍפ¬¤¢¤ë¡£ value °ú¤­¿ô¤Ï¿·¤·¤¤¥»¥Þ¥Õ¥©¤Î½é´üÃͤò»ØÄꤹ¤ë¡£ O_CREAT ¤¬»ØÄꤵ¤ì¡¢»ØÄꤷ¤¿Ì¾Á° name ¤Î¥»¥Þ¥Õ¥©¤¬¤¹¤Ç¤Ë¸ºß¤¹¤ë¾ì¹ç¡¢ mode ¤È value ¤Ï̵»ë¤µ¤ì¤ë¡£

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À®¸ù¤¹¤ë¤È¡¢ sem_open() ¤Ï¿·¤·¤¤¥»¥Þ¥Õ¥©¤Î¥¢¥É¥ì¥¹¤òÊÖ¤¹¡£ ¤³¤Î¥¢¥É¥ì¥¹¤Ï¾¤Î¥»¥Þ¥Õ¥©´ØÏ¢¤Î´Ø¿ô¤ò¸Æ¤Ó½Ð¤¹ºÝ¤Ë»ÈÍѤµ¤ì¤ë¡£ ¥¨¥é¡¼¤Î¾ì¹ç¡¢ sem_open() ¤Ï SEM_FAILED ¤òÊÖ¤·¡¢ errno ¤Ë¥¨¥é¡¼¤ò¼¨¤¹Ãͤò¥»¥Ã¥È¤¹¤ë¡£

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EACCES

¤½¤Î¥»¥Þ¥Õ¥©¤¬Â¸ºß¤¹¤ë¤¬¡¢¸Æ¤Ó½Ð¤·¸µ¤Ë¤Ï¤½¤Î¥»¥Þ¥Õ¥©¤ò¥ª¡¼¥×¥ó¤¹¤ë µö²Ä¤¬¤Ê¤¤¡£

EEXIST

oflag ¤Ë O_CREAT ¤È O_EXCL ¤ÎξÊý¤¬»ØÄꤵ¤ì¤¿¤¬¡¢ name ¤È¤¤¤¦Ì¾Á°¤Î¥»¥Þ¥Õ¥©¤Ï¤¹¤Ç¤Ë¸ºß¤¹¤ë¡£

EINVAL

value ¤¬ SEM_VALUE_MAX ¤è¤ê¤âÂ礭¤¤¡£

EMFILE

¥ª¡¼¥×¥ó¤µ¤ì¤¿¥Õ¥¡¥¤¥ë¿ô¤¬¤¹¤Ç¤Ë¤½¤Î¥×¥í¥»¥¹¤Ë¤ª¤±¤ë¾å¸Â¤Ë㤷¤Æ¤¤¤ë¡£

ENAMETOOLONG

name ¤¬Ä¹¤¹¤®¤ë¡£

ENFILE

¥ª¡¼¥×¥ó¤µ¤ì¤¿¥Õ¥¡¥¤¥ëÁí¿ô¤¬¥·¥¹¥Æ¥àÁ´ÂΤǤξå¸Â¤Ë㤷¤Æ¤¤¤ë¡£

ENOENT

oflag ¤Ë O_CREAT ¥Õ¥é¥°¤¬»ØÄꤵ¤ì¤Æ¤ª¤é¤º¡¢ name ¤È¤¤¤¦Ì¾Á°¤Î¥»¥Þ¥Õ¥©¤â¸ºß¤·¤Ê¤¤¡£

ENOMEM

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POSIX.1-2001.

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sem_close(3), sem_getvalue(3), sem_post(3), sem_unlink(3), sem_wait(3), sem_overview(7)