以下常量由本扩展模块定义，因此只有在本扩展模块被编译到 PHP 中，或者在运行时被动态加载后才有效。
| Constant | Value | Description |
|---|---|---|
| GOPHER_DOCUMENT | 0 | Standard text/plain document. |
| GOPHER_DIRECTORY | 1 | A resource containing a gopher formatted directory listing. |
| GOPHER_BINHEX | 4 | A BinHex encoded binary file. |
| GOPHER_DOSBINARY | 5 | A DOS formatted binary archive. |
| GOPHER_UUENCODED | 6 | A UUEncoded file. |
| GOPHER_BINARY | 9 | A generic binary file. |
| GOPHER_INFO | 255 | An Informational entry |
| GOPHER_HTTP | 254 | A reference to an HTTP resource. |
| GOPHER_UNKNOWN | -1 | An unrecognized entry. |