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msgctl — ???å????????楪?ڥ졼??????

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Standard C Library (libc, -lc)

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<sys/types.h> <sys/ipc.h> <sys/msg.h> int msgctl(int msqid, int cmd, struct msqid_ds *buf)

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msgctl() ?????ƥॳ?????ϡ? msqid ?????ꤹ?????å????????塼???Ф??????楪?ڥ졼?????????¹Ԥ??ޤ???

?ƥ??å????????塼?ˤϡ??????˴?Ϣ?????ǡ?????¤?Τ??????ޤ??? ???ΰ????? msgctl() ???ѹ??Ǥ??ޤ??? msgctl() ?Υ??????????????????ǡ?????¤?⤢???ޤ??????Υǡ?????¤?Τ? ⟨sys/msg.h⟩ ?????????졢?ʲ??Τ褦?ʥ????Ф??ޤޤ??Ƥ??ޤ? (????¾?Υ????Ф? ?????ޤ?)??

struct msqid_ds {
        struct  ipc_perm msg_perm; /* ???å????????塼?Υѡ??ߥå??????ӥå? */
        struct  msg *msg_first; /* ???塼?κǽ??Υ??å????? */
        struct  msg *msg_last; /* ???塼?κǸ??Υ??å????? */
        u_long  msg_cbytes; /* ???塼?ǻ??Ѥ??Ƥ????Х??ȿ? */
        u_long  msg_qnum; /* ???塼?ǻ??Ѥ??Ƥ??????å??????? */
        u_long  msg_qbytes; /* ???塼?ǻ??Ѥ????????Х??ȿ? */
        pid_t   msg_lspid; /* ?Ǹ??? msgsnd ?Υץ?????ID  */
        pid_t   msg_lrpid; /* ?Ǹ??? msgrcv ?Υץ?????ID  */
        time_t  msg_stime; /* ?Ǹ??? msgsnd ?λ???  */
        long    msg_pad1;
        time_t  msg_rtime; /* ?Ǹ??? msgrcv ?λ???  */
        long    msg_pad2;
        time_t  msg_ctime; /* ?Ǹ??? msgctl ?λ???  */
        long    msg_pad3;
        long    msg_pad4[4];
    };

shmid_ds ??¤?Τ????ǻ??Ѥ????? ipc_perm ??¤?Τϡ? ⟨sys/ipc.h⟩ ?ǰʲ??Τ褦???????????Ƥ??ޤ???

struct ipc_perm {
        ushort  cuid;   /* ?????ԤΥ桼??ID */
        ushort  cgid;   /* ?????ԤΥ??롼??ID */
        ushort  uid;    /* ?桼??ID */
        ushort  gid;    /* ???롼??ID */
        ushort  mode;   /* r/w ?ѡ??ߥå????? */
        ushort  seq;    /* ???????????ֹ? (???դ????????줿 msg/sem/shm ID) */
        key_t   key;    /* ?桼???????ꤷ?? msg/sem/shm ???? */
};

msgctl() ???¹Ԥ??륪?ڥ졼???????ϡ??ʲ??Τ????? 1 ?Ĥ? cmd ?ǻ??ꤵ???ޤ???

IPC_STAT

???å????????塼?ξ????򽸤ᡢ buf ???ؤ???¤?Τ????֤??ޤ???

IPC_SET

msqid ?˴?Ϣ???빽¤?Τ? msg_perm.uid ?ե??????ɡ? msg_perm.gid ?ե??????ɡ? msg_perm.mode ?ե??????ɡ? msg_qbytes ?ե??????ɤ??ͤ????ꤷ?ޤ????????ͤϡ? buf ???ؤ???¤?Τ??б??????ե??????ɤ??????????ޤ??????Υ??ڥ졼???????? ?¹ԤǤ????Τϡ??????ѥ桼?????ޤ??ϥ??å????????塼?˴?Ϣ???? ?ǡ?????¤?Τ? msg_perm.cuid ?? msg_perm.uid ?????????¸??桼?? ID ?????ĥץ??????ΤߤǤ??? msg_qbytes ???ͤ????䤻???Τϡ??????ѥ桼???ΤߤǤ????????ƥ????? ( ⟨sys/msg.h⟩ ?? MSGMNB) ???ۤ??? msg_qbytes ???ͤϡ????????¤??ڤ??ΤƤ????ޤ???

IPC_RMID

msqid ?????ꤹ?????å????????塼?????????? msqid ?˴?Ϣ???? ?ǡ??????˲????ޤ????????ѥ桼?????ޤ??ϡ????塼?? ??Ϣ?????ǡ?????¤?Τ? msg_perm.cuid ?ޤ??? msg_perm.uid ???ͤ????¸??桼?? ID ?????????ץ??????Τߤ??????????¹ԤǤ??ޤ???

???å????????塼???????ɹ??߸??????å????????塼?ؤν????߸? ( msgsnd(3) ?? msgrcv(3) ????) ?ϡ??ե???????Ʊ???褦?? ( chmod(2) ????)?? msg_perm.mode ?ե??????ɤˤ??äƷ??ޤ??ޤ????¸??桼?? ID ?ϡ? msg_perm.cuid ?ե??????ɤ? msg_perm.uid ?ե??????ɤȰ??פ????¸????롼?? ID ?ϡ? msg_perm.cgid ?? msg_perm.gid ?Ȱ??פ??ޤ???

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The msgctl() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

???顼

msgctl() ?ϡ??ʲ??Τ褦?ʾ????˥??顼?Ȥʤ??ޤ???

[EPERM]

cmd ?? IPC_SET ?? IPC_RMID ???????????ƽФ?¦???????ѥ桼???ǤϤʤ????硣 ?ޤ??ϼ¸??桼?? ID ?????å????????塼?˴?Ϣ?????ǡ?????¤?? msg_perm.uid ?ե??????ɤ? msg_perm.cuid ?ե??????ɤȰ??פ??ʤ????硣

IPC_SET ???Ѥ??? msg_qbytes ???ͤ??夲?褦?Ȥ????????ƽФ?¦???????ѥ桼???Ǥʤ????硣

[EACCES]

???ޥ??ɤ? IPC_STAT ?Ǥ??뤬?????Υ??å????????塼?? ?ɹ??߸????ƽФ?¦?ˤʤ????硣

[EINVAL]

msqid ???????????å????????塼 ID ?Ǥʤ????硣

cmd ???????????ޥ??ɤǤʤ????硣

[EFAULT]

buf ???????????ɥ쥹?????ꤷ?Ƥ??ʤ????硣

??Ϣ????

msgget(3), msgrcv(3), msgsnd(3)

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???å????????塼?ϡ? AT&T System V UNIX ?κǽ??Υ??꡼?????ɲä????ޤ?????