Table 1 Shared Memory file-like access modes
| Access Mode: | Shared Memory does not exist: |
Shared Memory already exists: |
|---|---|---|
| "r" | error | read-only access |
| "r+" | error | open for updating |
| "w" | create shmem | error |
| "w+" | create shmem | open for updating |
| "rp" | error | read and pin shmem |
| "wp" | create and pin shmem | error |