## 1. Failed to run the KV store on the LiteOS Cortex-A kernel \(Hi3516 or Hi3518\) due to incorrect path setting for the KV store<a name="section2041345718513"></a>
**Symptom**
When the LiteOS Cortex-A kernel \(Hi3516 or Hi3518 platform\) directly calls the API provided by the KV store, the compiled executable program fails to run.
**Possible Causes**
The compiled executable program is run directly without being converted to an application using **AbilityKit** APIs. In this case, the Bundle Manager Service \(BMS\) cannot correctly set the path for storing application data during application installation. As a result, the KV store fails to run.
**Solution**
Call the **UtilsSetEnv** function of the KV store to set the data storage path.
## Available APIs<a name="section1633115419401"></a>
**Table 1** APIs for file operations
| Function | Description |
| ---------- | ------------- |
| int UtilsFileOpen(const char* path, int oflag, int mode) | Opens or creates a file. |
| int UtilsFileClose(int fd) | Closes a file with a specified file descriptor. |
| int UtilsFileRead(int fd, char *buf, unsigned int len) | Reads a specified length of data from a file with the specified file descriptor and writes the data into the buffer. |
| int UtilsFileWrite(int fd, const char *buf, unsigned int len) | Writes a specified length of data into a file with the specified file descriptor. |
| int UtilsFileDelete(const char *path) | Deletes a specified file. |
| int UtilsFileStat(const char *path, unsigned int *fileSize) | Obtains the file size. |
| int UtilsFileSeek(int fd, int offset, unsigned int whence) | Adjusts the read and write position offset in a file. |
| int UtilsFileCopy(const char* src, const char* dest) | Copies the source file to a target file. |
| int UtilsFileMove(const char* src, const char* dest) | Moves the source file into a target file. |
Sample code for file operations:
# Commonlibrary Development Guidelines<a name="EN-US_TOPIC_0000001059307279"></a>
## Overview
The **commonlibrary** subsystem stores basic OpenHarmony components which provides common enhanced APIs for development in C, C++ and JS that are commonly used by OpenHarmony service subsystems and upper-layer applications. Including repositories:
- Add resource files in the **res/drawable** directory based on the following directory structure.
- Compress the **libLauncher.so**, **config.json**, and resource files into a ZIP package and change the file name extension to **.hap**, for example, **Launcher.hap**.
2. Connect the development board and send the command for installing the native KV store application to the board through the serial port.
See [Development Guidelines for c_utils](https://gitee.com/openharmony/commonlibrary_c_utils/blob/master/docs/en/c-utils-guide.md), including FAQs for several scenarios.
The **commonlibrary** subsystem provides common enhanced APIs for development in C, C++ and JS.
The **commonlibrary** subsystem stores basic OpenHarmony components which provides common enhanced APIs for development in C, C++ and JS that are commonly used by OpenHarmony service subsystems and upper-layer applications. Including repositories:
```
/commonlibrary
├── c_utils # Enhanced basic C/C++ library for developers
├── ets_utils # Enhanced basic JS library for developers
└── utils_lite # Basic tools for liteOS, including C and JS.
```
Features provided by every repositories are listed here:
**c_utils**
...
...
@@ -24,15 +31,8 @@ The **commonlibrary** subsystem provides common enhanced APIs for development in
- Hardware Abstraction Layer (HAL) APIs for performing operations on standard files
