# mq\_attr
## **Overview**
**Related Modules:**
[IPC](IPC.md)
**Description:**
Describes message queue attributes.
## **Summary**
## Data Fields
## **Details**
## **Field Documentation**
## \_\_unused
```
long mq_attr::__unused[4]
```
**Description:**
A reserved field
## mq\_curmsgs
```
long mq_attr::mq_curmsgs
```
**Description:**
Number of messages currently queued
## mq\_flags
```
long mq_attr::mq_flags
```
**Description:**
Message queue flags: 0 or **O\_NONBLOCK**
## mq\_maxmsg
```
long mq_attr::mq_maxmsg
```
**Description:**
Maximum number of messages on queue
## mq\_msgsize
```
long mq_attr::mq_msgsize
```
**Description:**
Maximum length of a message