MSG_STAT_QUEUE(3) 1 MSG_STAT_QUEUE(3)msg_stat_queue - Returns information from the message queue data structureSYNOPSIS
array msg_stat_queue (resource $queue)
DESCRIPTION msg_stat_queue(3) returns the message queue meta data for the message queue specified by the $queue. This is useful, for example, to deter-
mine which process sent the message that was just received.
PARAMETERS
o $queue
- Message queue resource handle
RETURN VALUES
The return value is an array whose keys and values have the following meanings:
Array structure for msg_stat_queue
+--------------+---------------------------------------------------+
| | |
|msg_perm.uid | |
| | |
| | The uid of the owner of the queue. |
| | |
| | |
|msg_perm.gid | |
| | |
| | The gid of the owner of the queue. |
| | |
| | |
|msg_perm.mode | |
| | |
| | The file access mode of the queue. |
| | |
| | |
| msg_stime | |
| | |
| | The time that the last message was sent to the |
| | queue. |
| | |
| | |
| msg_rtime | |
| | |
| | The time that the last message was received from |
| | the queue. |
| | |
| | |
| msg_ctime | |
| | |
| | The time that the queue was last changed. |
| | |
| | |
| msg_qnum | |
| | |
| | The number of messages waiting to be read from |
| | the queue. |
| | |
| | |
| msg_qbytes | |
| | |
| | The maximum number of bytes allowed in one mes- |
| | sage queue. On Linux, this value may be read and |
| | modified via /proc/sys/kernel/msgmnb. |
| | |
| | |
| msg_lspid | |
| | |
| | The pid of the process that sent the last mes- |
| | sage to the queue. |
| | |
| | |
| msg_lrpid | |
| | |
| | The pid of the process that received the last |
| | message from the queue. |
| | |
+--------------+---------------------------------------------------+
SEE ALSO msg_remove_queue(3), msg_receive(3), msg_get_queue(3), msg_set_queue(3).
PHP Documentation Group MSG_STAT_QUEUE(3)
Check Out this Related Man Page
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 Alsomsgctl(2), msgop(2), ftok(3)msgget(2)