下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。
| Constant | Description |
|---|---|
FAMChanged (integer)
|
Some value which can be obtained with fstat(1) changed for a file or directory. |
FAMDeleted (integer)
|
A file or directory was deleted or renamed. |
FAMStartExecuting (integer)
|
An executable file started executing. |
FAMStopExecuting (integer)
|
An executable file that was running finished. |
FAMCreated (integer)
|
A file was created in a directory. |
FAMMoved (integer)
|
This event never occurs. |
FAMAcknowledge (integer)
|
An event in response to fam_cancel_monitor(). |
FAMExists (integer)
|
An event upon request to monitor a file or directory. When a directory is monitored, an event for that directory and every file contained in that directory is issued. |
FAMEndExist (integer)
|
Event after the last FAMEExists event. |