# shminfo
- [Overview](#section764815373165637)
- [Summary](#section1169491627165637)
- [Data Fields](#pub-attribs)
- [Details](#section747444635165637)
- [Field](#section1868399011165637)
- [\_\_unused](#a68b65a802c7b3bc6d911ed41808203ef)
- [shmall](#a4b74fbc85e2805f7b99f6aecde00c570)
- [shmmax](#a2d7778854ce2e55499a2036da769905a)
- [shmmin](#a9940d32ac5484be0f5df79296d9bc97a)
- [shmmni](#a084bc8449e6683ede60a6445255d14bd)
- [shmseg](#a11ee1150ca8aaad294c17fe939f35688)
## **Overview**
**Related Modules:**
[MEM](MEM.md)
**Description:**
Describes limitations and attributes of system-level shared memory.
## **Summary**
## Data Fields
## **Details**
## **Field **
## \_\_unused
```
unsigned long shminfo::__unused[4]
```
**Description:**
Reserved
## shmall
```
unsigned long shminfo::shmall
```
**Description:**
Maximum size of all shared memory segments allowed by the system
## shmmax
```
unsigned long shminfo::shmmax
```
**Description:**
Maximum size of a shared memory segment allowed by the system
## shmmin
```
unsigned long shminfo::shmmin
```
**Description:**
Minimum size of a shared memory segment allowed by the system
## shmmni
```
unsigned long shminfo::shmmni
```
**Description:**
Maximum number of shared memory segments allowed by the system
## shmseg
```
unsigned long shminfo::shmseg
```
**Description:**
Maximum number of shared memory segments that can be attached by a process