xref: /docs/en/application-dev/file-management/native-fileio-guidelines.md

# Accessing Application Files (C/C++) 

## When to Use

The **FileIO** module provides APIs for basic file operations.

## Basic Concepts

URI: uniquely identifies a file.

## Constraints

- Before performing file operations, ensure that the URI or path passed in is correct and valid.

## Available APIs

For details about the APIs, see [FileIO](../reference/apis-core-file-kit/_file_i_o.md).

| API| Description|
| -------- | -------- |
| FileManagement_ErrCode OH_FileIO_GetFileLocation(char *uri, int uriLength, FileIO_FileLocation *location)| Obtains the location of a file.|
| enum FileIO_FileLocation FileIO_FileLocation| Enumerates the file locations.|
| enum enum FileManagement_ErrCode FileManagement_ErrCode| Enumerates the error codes used in the **FileIO** module.|

## How to Develop

**Adding the Dynamic Link Library**

Add the following library to **CMakeLists.txt**.

```txt
target_link_libraries(sample PUBLIC libohfileio.so)
```

**Adding the Header File**

```c++
#include <filemanagement/fileio/oh_fileio.h>
```

Use **OH_FileIO_GetFileLocation** to obtain the location of a file. <br>Example:
```c
    void GetFileLocationExample() {
        char *uri = "file://com.example.demo/data/storage/el2/base/files/test.txt";
        FileIO_FileLocation location;
        FileManagement_ErrCode ret = OH_FileIO_GetFileLocation(uri, strlen(uri), &location);
        if (ret == 0) {
            if (location == FileIO_FileLocation::LOCAL) {
                printf("This file is on local.");
            } else if (location == FileIO_FileLocation::CLOUD) {
                printf("This file is on cloud.");
            } else if (location == FileIO_FileLocation::LOCAL_AND_CLOUD) {
                printf("This file is both on local and cloud.");
            }
        } else {
            printf("GetFileLocation failed, error code is %d", ret);
        }
    }    
   ```