msgget(2) - osol9

1msgget(2)                        System Calls                        msgget(2)
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NAME

6       msgget - get message queue
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SYNOPSIS

9       #include <sys/msg.h>
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11       int msgget(key_t key, int msgflg);
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DESCRIPTION

15       The  msgget()  argument returns the message queue identifier associated
16       with key.
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19       A message queue identifier and associated message queue and data struc‐
20       ture  (see  Intro(2))  are  created for key if one of the following are
21       true:
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23           o      key is IPC_PRIVATE.
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25           o      key does not already have a message queue identifier associ‐
26                  ated with it, and (msgflg&IPC_CREAT) is true.
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29       On  creation,  the data structure associated with the new message queue
30       identifier is initialized as follows:
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32           o      msg_perm.cuid, msg_perm.uid, msg_perm.cgid, and msg_perm.gid
33                  are  set  to  the  effective user ID and effective group ID,
34                  respectively, of the calling process.
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36           o      The low-order 9 bits of msg_perm.mode are set  to  the  low-
37                  order 9 bits of msgflg.
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39           o      msg_qnum, msg_lspid, msg_lrpid, msg_stime, and msg_rtime are
40                  set to 0.
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42           o      msg_ctime is set to the current time.
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44           o      msg_qbytes is set to the system limit. See NOTES.
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RETURN VALUES

47       Upon successful completion, a non-negative integer representing a  mes‐
48       sage  queue identifier is returned. Otherwise, −1 is returned and errno
49       is set to indicate the error.
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ERRORS

52       The msgget() function will fail if:
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54       EACCES    A message queue identifier exists for key, but operation per‐
55                 mission  (see  Intro(2)) as specified by the low-order 9 bits
56                 of msgflg would not be granted.
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59       EEXIST    A   message   queue   identifier   exists   for    key    but
60                 (msgflg&IPC_CREAT) and (msgflg&IPC_EXCL) are both true.
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63       ENOENT    A  message  queue  identifier  does  not  exist  for  key and
64                 (msgflg&IPC_CREAT) is false.
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67       ENOSPC    A message queue identifier is to be created but  the  system-
68                 imposed  limit on the maximum number of allowed message queue
69                 identifiers system wide would be exceeded. See NOTES.
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ATTRIBUTES

73       See attributes(5) for descriptions of the following attributes:
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78       ┌─────────────────────────────┬─────────────────────────────┐
79       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
80       ├─────────────────────────────┼─────────────────────────────┤
81       │Interface Stability          │Standard                     │
82       └─────────────────────────────┴─────────────────────────────┘
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NOTES

89       The  system-defined  limit used to initialize msg_qbytes is the minimum
90       enforced value of the calling process's process.max-msg-qbytes resource
91       control.
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94       The  system-imposed limit on the number of message queue identifiers is
95       maintained  on  a  per-project  basis  using  the   project.max-msg-ids
96       resource  control.  The zone.max-msg-ids resource control restricts the
97       total amount of message queue identifiers that can be  allocated  by  a
98       zone.
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101       See  rctladm(1M)  and  setrctl(2)  for information about using resource
102       controls.
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106SunOS 5.11                        14 Aug 2006                        msgget(2)