msgget(2) [sunos man page]

msgget(2)							   System Calls 							 msgget(2)

NAME

       msgget - get message queue

SYNOPSIS

       #include <sys/msg.h>

       int msgget(key_t key, int msgflg);

DESCRIPTION

       The msgget() argument returns the message queue identifier associated with key.

       A  message  queue identifier and associated message queue and data structure (see intro(2)) are created for key if one of the following are
       true:

	 o  key is IPC_PRIVATE.

	 o  key does not already have a message queue identifier associated with it, and (msgflg&IPC_CREAT) is true.

       On creation, the data structure associated with the new message queue identifier is initialized as follows:

	 o  msg_perm.cuid, msg_perm.uid, msg_perm.cgid, and msg_perm.gid are set to the effective user ID and effective group ID, respectively, of
	    the calling process.

	 o  The low-order 9 bits of msg_perm.mode are set to the low-order 9 bits of msgflg.

	 o  msg_qnum, msg_lspid, msg_lrpid, msg_stime, and msg_rtime are set to 0.

	 o  msg_ctime is set to the current time.

	 o  msg_qbytes is set to the system limit. See NOTES.

RETURN VALUES

       Upon successful completion, a non-negative integer representing a message queue identifier is returned. Otherwise, -1 is returned and errno
       is set to indicate the error.

ERRORS

       The msgget() function will fail if:

       EACCES	       A message queue identifier exists for key, but operation permission (see intro(2)) as specified by the low-order 9 bits	of
		       msgflg would not be granted.

       EEXIST	       A message queue identifier exists for key but (msgflg&IPC_CREAT) and (msgflg&IPC_EXCL) are both true.

       ENOENT	       A message queue identifier does not exist for key and (msgflg&IPC_CREAT) is false.

       ENOSPC	       A  message  queue  identifier  is to be created but the system-imposed limit on the maximum number of allowed message queue
		       identifiers system wide would be exceeded. See NOTES.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       rctladm(1M), intro(2), msgctl(2), msgrcv(2), msgsnd(2), setrctl(2), ftok(3C), attributes(5), standards(5)

NOTES

       The system-defined limit used to initialize msg_qbytes is the minimum  enforced	value  of  the	calling  process's  process.max-msg-qbytes
       resource control.

       The  system-imposed  limit  on  the  number of message queue identifiers is maintained on a per-project basis using the project.max-msg-ids
       resource control.

	See rctladm(1M) and setrctl(2) for information about using resource controls.

SunOS 5.10							    11 Feb 2003 							 msgget(2)

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msgget(2)							System Calls Manual							 msgget(2)

Name
       msgget - get message queue

Syntax
       #include <sys/types.h>
       #include <sys/ipc.h>
       #include <sys/msg.h>

       int msgget (key, msgflg)
       key_t key;
       int msgflg;

Description
       The system call returns the message queue identifier associated with key.

       A message queue identifier and associated message queue and data structure are created for key if one of the following is true:

       o    The key is equal to IPC_PRIVATE

       o    The  key  does not already have a message queue identifier associated with it, and (msgflg & IPC_CREAT) is true.  For further informa-
	    tion, see

       Upon creation, the data structure associated with the new message queue identifier is initialized as follows:

       o    The msg_perm.cuid, msg_perm.uid, msg_perm.cgid and msg_perm.gid members are set equal to the effective user ID and effective group ID,
	    respectively, of the calling process.

       o    The low-order nine bits of msg_perm.mode are set equal to the low-order nine bits of msgflg.

       o    The msg_qnum, msg_lspid, msg_lrpid, msg_stime, and mgs_rtime members are set equal to 0.

       o    The msg_ctime is set equal to the current time.

       o    The msg_qbytes is set equal to the system limit.

Return Values
       Upon  successful  completion,  a  non-negative  integer,  which	is  a  message queue identifier, is returned.  Otherwise, a value of -1 is
       returned, and errno is set to indicate the error.

Diagnostics
       The system call fails under the following conditions:

       [EACCES]       A message queue identifier exists for key but operations permission, as specified by the	low-order  nine  bits  of  msgflg,
		      would not be granted.  For further information, see

       [ENOENT]       A message queue identifier does not exist for key and the logical operation (msgflg & IPC_CREAT) is false.

       [ENOSPC]       A  message  queue  identifier  is to be created, but the system-imposed limit on the maximum number of allowed message queue
		      identifiers system wide would be exceeded.

       [EEXIST]       A message queue identifier exists for key but the logical operation ((msgflg & IPC_CREAT ) & (msgflg & IPC_EXCL )) is true.

See Also
       msgctl(2), msgop(2), ftok(3)

																	 msgget(2)

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msgget(2) [sunos man page]

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