FileUri Development (C/C++)

When to Use

You can use the APIs provided by the fileUri module to perform basic URI operations.

Basic Concepts

result: path or URI that meets the service requirements.

Constraints

• The parameters passed in must be correct and valid before a URI is converted or verified.

• To ensure data accuracy, only one object can be processed during the conversion or verification of a URI.

Available APIs

For details about the APIs, see File URI.

API	Description
FileManagement_ErrCode OH_FileUri_GetUriFromPath(const char *path, unsigned int length, char **result)	Obtains the URI from a path.
FileManagement_ErrCode OH_FileUri_GetPathFromUri(const char *uri, unsigned int length, char **result)	Obtains the sandbox path from a URI.
FileManagement_ErrCode OH_FileUri_GetFullDirectoryUri(const char *uri, unsigned int length, char **result)	Obtains the URI of the directory, in which a URI is located.
bool OH_FileUri_IsValidUri(const char *uri, unsigned int length)	Checks whether a URI is valid.
FileManagement_ErrCode OH_FileUri_GetFileName(const char *uri, unsigned int length, char **result)	Obtains the file name based on the given URI.

How to Develop

Adding the Dynamic Link Library

Add the following library to CMakeLists.txt.

target_link_libraries(sample PUBLIC libohfileuri.so)

Adding the Header File

#include <filemanagement/file_uri/oh_file_uri.h>

1. Call OH_FileUri_GetUriFromPath to obtain the URI from a path. The memory allocated must be released using free().
   Example:

    #include <cstring>
   
    void OH_FileUri_GetUriFromPathExample() {
        char *path = "/data/storage/el2/base/files/test.txt";
        unsigned int length = strlen(path);
        char *uriResult = NULL;
        FileManagement_ErrCode ret = OH_FileUri_GetUriFromPath(path, length ,&uriResult); 
        if (ret == 0 && uriResult !=NULL) {
            printf("pathUri= %s", uriResult); // The URI obtained by application a is file://com.example.demo/data/storage/el2/base/files/test.txt.
        }
        if (uriResult != NULL) {
            free(uriResult);
        }
    }    
   

2. Call OH_FileUri_GetPathFromUri to convert the URI into a path. The memory allocated must be released using free().
   Example:

    #include <cstring>
   
    void OH_FileUri_GetPathFromUriExample() {
        char *uri = "file://com.example.demo/data/storage/el2/base/files/test.txt";
        unsigned int length = strlen(uri);
        char *pathResult = NULL;
        FileManagement_ErrCode ret = OH_FileUri_GetPathFromUri(uri, length, &pathResult);
        if (ret == 0 && pathResult != NULL) {
            printf ("pathResult= %s", pathResult); // PathResult is /data/storage/el2/base/files/test.txt.
        }
        if (pathResult != NULL) {
            free(pathResult);
        }
    }
   

3. Call OH_FileUri_GetFullDirectoryUri to obtain the URI of the directory where the specified URI is located. The memory allocated must be released using free().
   Example:

    #include <cstring>
    
    void OH_FileUri_GetFullDirectoryUriExample() {
        char *uri = "file://com.example.demo/data/storage/el2/base/files/test.txt";
        unsigned int length = strlen(uri);
        char *uriResult = NULL;
        FileManagement_ErrCode ret = OH_FileUri_GetFullDirectoryUri(uri, length, &uriResult);
        if (ret == 0 && uriResult != NULL) {
            printf("pathUri= %s",uriResult);// The URI obtained is file://com.example.demo/data/storage/el2/base/files/.
        }
        if (uriResult != NULL) {
            free(uriResult);
        }
    }
   

4. Call OH_FileUri_IsValidUri to check whether a URI is valid.
   Example:

    #include <cstring>
    
    void OH_FileUri_IsValidUriExample() {
        char *uri = "file://com.example.demo/data/storage/el2/base/files/test.txt";
        unsigned int length = strlen(uri);
        bool falgs = OH_FileUri_IsValidUri(uri, length);
        printf("The URI is valid? falgs=%d", falgs);
    }
   

5. Call OH_FileUri_GetFileName to obtain the file name from the URI. The memory allocated must be released using free().
   Example:

    #include <cstring>
    
    void OH_FileUri_GetFileNameExample() {
        char *uri = "file://com.example.demo/data/storage/el2/base/files/test.txt";
        unsigned int length = strlen(uri);
        char *uriResult = NULL;
        FileManagement_ErrCode ret = OH_FileUri_GetFileName(uri, length, &uriResult);
        if (ret == 0 && uriResult != NULL) {
            printf ("pathUri=%s,"uriResult);// Obtain the file name test.txt from the URI.
        }
        if (uriResult != NULL) {
            free(uriResult);
        }
    }