Obtaining the User Directory Environment (C/C++)

When to Use

You can use Environment to allow a third-party application to access files in a user directory.

Constraints

• Before using the APIs of the Environment module, ensure that the device has SystemCapability.FileManagement.File.Environment.FolderObtain.
• The APIs provided by the Environment module can be used to obtain the application sandbox paths of the user directories. To operate the related directory and its subdirectories, user authorization is required via a dialog box. For details, see Requesting User Authorization.

Available APIs

For details about the APIs, see oh_environment.h.

API	Description
FileManagement_ErrCode OH_Environment_GetUserDownloadDir (char **result)	Obtains the sandbox path of the Download directory. This function supports only 2-in-1 devices.
FileManagement_ErrCode OH_Environment_GetUserDesktopDir (char **result)	Obtains the sandbox path of the Desktop directory. This function supports only 2-in-1 devices.
FileManagement_ErrCode OH_Environment_GetUserDocumentDir (char **result)	Obtains the sandbox path of the Documents directory. This function supports only 2-in-1 devices.

How to Develop

Adding the Dynamic Link Library

Add the following library to CMakeLists.txt.

target_link_libraries(sample PUBLIC libohenvironment.so libhilog_ndk.z.so)

Adding Header Files

#include <cstdlib>
#include <filemanagement/environment/oh_environment.h>
#include <filemanagement/fileio/oh_fileio.h>
#include <hilog/log.h>

1. Call OH_Environment_GetUserDownloadDir to obtain the sandbox path of the user Download directory. The memory allocated must be released using free().
   Example:

   void GetUserDownloadDirPathExample()
   {
       char *downloadPath = nullptr;
       FileManagement_ErrCode ret = OH_Environment_GetUserDownloadDir(&downloadPath);
       if (ret == 0) {
           OH_LOG_INFO(LOG_APP, "Download Path=%{public}s", downloadPath);
           free(downloadPath);
       } else {
           OH_LOG_ERROR(LOG_APP, "GetDownloadPath fail, error code is %{public}d", ret);
       }
   }
   

   napi_init.cpp

2. Call OH_Environment_GetUserDesktopDir to obtain the sandbox path of the user Desktop directory. The memory allocated must be released using free().
   Example:

   void GetUserDesktopDirPathExample()
   {
       char *desktopPath = nullptr;
       FileManagement_ErrCode ret = OH_Environment_GetUserDesktopDir(&desktopPath);
       if (ret == 0) {
           OH_LOG_INFO(LOG_APP, "Desktop Path=%{public}s", desktopPath);
           free(desktopPath);
       } else {
           OH_LOG_ERROR(LOG_APP, "GetDesktopPath fail, error code is %{public}d", ret);
       }
   }
   

   napi_init.cpp

3. Call OH_Environment_GetUserDocumentDir to obtain the sandbox path of the user Document directory. The memory allocated must be released using free().
   Example:

   void GetUserDocumentDirPathExample()
   {
       char *documentPath = nullptr;
       FileManagement_ErrCode ret = OH_Environment_GetUserDocumentDir(&documentPath);
       if (ret == 0) {
           OH_LOG_INFO(LOG_APP, "Document Path=%{public}s", documentPath);
           free(documentPath);
       } else {
           OH_LOG_ERROR(LOG_APP, "GetDocumentPath fail, error code is %{public}d", ret);
       }
   }
   

   napi_init.cpp

4. Call OH_Environment_GetUserDocumentDir to obtain the sandbox path of the user Document directory, and use the stat function to determine the space of the Document directory.
   Example:

   Include the following header file before using the API.

   #include <sys/stat.h>
   

   void GetUserDownloadDirSizeExample()
   {
       char *documentPath = nullptr;
       FileManagement_ErrCode ret = OH_Environment_GetUserDocumentDir(&documentPath);
       if (ret == 0) {
           OH_LOG_INFO(LOG_APP, "Document Path=%{public}s", documentPath);
           struct stat fileStat;
           int result = stat(documentPath, &fileStat);
           if (result == 0) {
               OH_LOG_INFO(LOG_APP, "Document Size=%{public}ld", fileStat.st_size);
           } else {
               OH_LOG_ERROR(LOG_APP, "GetDocumentSize fail, error code is %{public}ld", result);
           }
           free(documentPath);
       } else {
           OH_LOG_ERROR(LOG_APP, "GetDocumentPath fail, error code is %{public}d", ret);
       }
   }
   

   napi_init.cpp