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4 .\" Copyright (C) 2006 Michael Kerrisk <mtk.manpages@gmail.com>
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26 .\" Japanese Version Copyright (c) 2006 Akihiro MOTOKI all rights reserved.
27 .\" Translated 2006-04-23, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
28 .\" Updated 2008-11-09, Akihiro MOTOKI, LDP v3.13
30 .TH MQ_GETATTR 3 2010-08-29 "Linux" "Linux Programmer's Manual"
33 .\"O mq_getattr, mq_setattr \- get/set message queue attributes
34 mq_getattr, mq_setattr \- ¥á¥Ã¥»¡¼¥¸¥¥å¡¼¤Î°À¤òÀßÄê/¼èÆÀ¤¹¤ë
38 .B #include <mqueue.h>
40 .BI "int mq_getattr(mqd_t " mqdes ", struct mq_attr *" attr );
42 .BI "int mq_setattr(mqd_t " mqdes ", struct mq_attr *" newattr ","
43 .BI " struct mq_attr *" oldattr );
46 .\"O Link with \fI\-lrt\fP.
47 \fI\-lrt\fP ¤Ç¥ê¥ó¥¯¤¹¤ë¡£
50 .\"O .BR mq_getattr ()
52 .\"O .BR mq_setattr ()
53 .\"O respectively retrieve and modify attributes of the message queue
54 .\"O referred to by the descriptor
61 ¤Ç»²¾È¤µ¤ì¤ë¥á¥Ã¥»¡¼¥¸¥¥å¡¼¤Î°À¤Î¼èÆÀ¤ÈÊѹ¹¤ò¤½¤ì¤¾¤ì¹Ô¤¦¡£
63 .\"O .BR mq_getattr ()
66 .\"O structure in the buffer pointed by
68 .\"O This structure is defined as:
74 ¹½Â¤ÂΤò³ÊǼ¤·¤ÆÊÖ¤¹¡£¤³¤Î¹½Â¤ÂΤϰʲ¼¤Î¤è¤¦¤ËÄêµÁ¤µ¤ì¤Æ¤¤¤ë:
79 .\"O long mq_flags; /* Flags: 0 or O_NONBLOCK */
80 .\"O long mq_maxmsg; /* Max. # of messages on queue */
81 .\"O long mq_msgsize; /* Max. message size (bytes) */
82 .\"O long mq_curmsgs; /* # of messages currently in queue */
83 long mq_flags; /* ¥Õ¥é¥°: 0 ¤« O_NONBLOCK */
84 long mq_maxmsg; /* ¥¥å¡¼¤ÎºÇÂç¥á¥Ã¥»¡¼¥¸¿ô */
85 long mq_msgsize; /* ºÇÂç¥á¥Ã¥»¡¼¥¸¥µ¥¤¥º (¥Ð¥¤¥Èñ°Ì) */
86 long mq_curmsgs; /* ¥¥å¡¼¤Ë¸½ºßÆþ¤Ã¤Æ¤¤¤ë¥á¥Ã¥»¡¼¥¸¿ô */
93 .\"O field contains flags associated with the open message queue description.
94 .\"O This field is initialized when the queue is created by
96 .\"O The only flag that can appear in this field is
99 ¥Õ¥£¡¼¥ë¥É¤Ë¤Ï¡¢¥ª¡¼¥×¥ó¥á¥Ã¥»¡¼¥¸¥¥å¡¼µ½Ò (open message queue
100 description) ¤Ë´ØÏ¢ÉÕ¤±¤é¤ì¤Æ¤¤¤ë¥Õ¥é¥°¤¬³ÊǼ¤µ¤ì¤ë¡£
103 ¤Ç¥¥å¡¼¤¬ºîÀ®¤µ¤ì¤ëºÝ¤Ë½é´ü²½¤µ¤ì¤ë¡£
104 ¤³¤Î¥Õ¥£¡¼¥ë¥É¤Ë¸½¤ì¤ë¥Õ¥é¥°¤Ï
112 .\"O fields are set when the message queue is created by
113 .\"O .BR mq_open (3).
119 ¤Ç¥á¥Ã¥»¡¼¥¸¥¥å¡¼¤¬ºîÀ®¤µ¤ì¤ëºÝ¤Ë¥»¥Ã¥È¤µ¤ì¤ë¡£
122 .\"O field is an upper limit on the number of messages
123 .\"O that may be placed on the queue using
124 .\"O .BR mq_send (3).
128 ¤ò»È¤Ã¤Æ¥¥å¡¼¤ËÆþ¤ì¤ë¤³¤È¤¬¤Ç¤¤ë¥á¥Ã¥»¡¼¥¸¿ô¤Î¾å¸Â¤Ç¤¢¤ë¡£
131 .\"O field is an upper limit on the size of messages
132 .\"O that may be placed on the queue.
134 ¥Õ¥£¡¼¥ë¥É¤Ï¡¢¥¥å¡¼¤ËÆþ¤ì¤ë¤³¤È¤¬¤Ç¤¤ë¥á¥Ã¥»¡¼¥¸¤Î
136 .\"O Both of these fields must have a value greater than zero.
139 .\"O files that place ceilings on the values for these fields are described in
140 .\"O .BR mq_open (3).
141 ¤³¤ì¤é¤Î¥Õ¥£¡¼¥ë¥É¤Ï¤É¤Á¤é¤â 0 ¤è¤êÂ礤ÊÃͤǤʤ±¤ì¤Ð¤Ê¤é¤Ê¤¤¡£
142 ¤³¤ì¤é¤Î¥Õ¥£¡¼¥ë¥É¤ËÀßÄê¤Ç¤¤ëÃͤξå¸Â¤Ï
144 ¥Õ¥¡¥¤¥ë¤Ë¤è¤ê·è¤Þ¤ë¡£
152 .\"O field returns the number of messages currently held in the queue.
154 ¥Õ¥£¡¼¥ë¥É¤Ï¥¥å¡¼¤Ë¸½ºß³ÊǼ¤µ¤ì¤Æ¤¤¤ë¥á¥Ã¥»¡¼¥¸¿ô¤òÊÖ¤¹¡£
156 .\"O .BR mq_setattr ()
157 .\"O sets message queue attributes using information supplied in the
159 .\"O structure pointed to by
166 ¹½Â¤ÂΤÇÍ¿¤¨¤é¤ì¤¿¾ðÊó¤ò»È¤Ã¤Æ¡¢¥á¥Ã¥»¡¼¥¸¥¥å¡¼¤Î°À¤òÀßÄꤹ¤ë¡£
167 .\"O The only attribute that can be modified is the setting of the
171 .\"O The other fields in
174 Êѹ¹¤¹¤ë¤³¤È¤¬¤Ç¤¤ë°À¤Ï¡¢
178 ¥Õ¥é¥°¤ÎÀßÄê¤À¤±¤Ç¤¢¤ë¡£
180 ¤Î¾¤Î¥Õ¥£¡¼¥ë¥É¤Ï̵»ë¤µ¤ì¤ë¡£
183 .\"O field is not NULL,
184 .\"O then the buffer that it points to is used to return an
186 .\"O structure that contains the same information that is returned by
187 .\"O .BR mq_getattr ().
189 ¥Õ¥£¡¼¥ë¥É¤¬ NULL °Ê³°¤Î¾ì¹ç¡¢
191 ¤¬ÊÖ¤¹¤Î¤ÈƱ¤¸¾ðÊó¤ò³ÊǼ¤·¤¿
195 ¤¬»Ø¤¹¥Ð¥Ã¥Õ¥¡¤ËÆþ¤ì¤ÆÊÖ¤¹¡£
196 .\"O .SH RETURN VALUE
199 .\"O .BR mq_getattr ()
201 .\"O .BR mq_setattr ()
202 .\"O return 0; on error, \-1 is returned, with
204 .\"O set to indicate the error.
209 ¤Ï 0 ¤òÊÖ¤¹¡£¥¨¥é¡¼¤Î¾ì¹ç¡¢\-1 ¤òÊÖ¤·¡¢
211 ¤Ë¥¨¥é¡¼¤ò¼¨¤¹ÃͤòÀßÄꤹ¤ë¡£
216 .\"O The descriptor specified in
220 ¤Ç»ØÄꤵ¤ì¤¿µ½Ò»Ò¤¬ÉÔÀµ¤Ç¤¢¤ë¡£
223 .\"O .I newattr\->mq_flags
224 .\"O contained set bits other than
225 .\"O .BR O_NONBLOCK .
226 .I newattr\->mq_flags
229 °Ê³°¤Î¥Ó¥Ã¥È¤¬¥»¥Ã¥È¤µ¤ì¤Æ¤¤¤¿¡£
230 .\"O .SH CONFORMING TO
236 .\"O .BR mq_getattr ()
238 .\"O .BR mq_setattr ()
239 .\"O are library functions layered on top of the
240 .\"O .BR mq_getsetattr (2)
246 ¤Ï¥é¥¤¥Ö¥é¥ê´Ø¿ô¤Ç¤¢¤ê¡¢
247 .BR mq_getsetattr (2)
248 ¥·¥¹¥Æ¥à¥³¡¼¥ë¤òÍѤ¤¤Æ¼ÂÁõ¤µ¤ì¤Æ¤¤¤ë¡£