# 5.5 The generic mapping

_Peios / Developing for Peios / SDK Reference / file.h — File Security_

> The canonical generic-to-specific rights mapping for the file object class, exported for you to pass to an access check.

```c
extern const struct kacs_generic_mapping peios_file_generic_mapping;
```

The canonical generic→specific rights mapping for the **file** object class. Pass it to [`peios_access_map_generic`](/peios/developing-for-peios/sdk-reference/sdk-security/security-h-security-descriptors.md#access-masks), or as the `mapping` in a [`peios_access_request`](/peios/developing-for-peios/sdk-reference/sdk-access/access-h-access-checks.md#the-request) when checking access against a file's SD — for example to pre-flight whether a caller could open a file before you actually open it.