Renaming Files and Directories

Renaming files or directories using std::filesystem::path involves the std::filesystem::rename() function. This function allows you to move or rename files and directories efficiently. Here’s how you can do it:

Renaming a File

Here’s an example of renaming a file:

1#include <filesystem>
2#include <iostream>
3
4namespace fs = std::filesystem;
5
6int main() {
7  fs::path oldPath{R"(C:\path\to\oldname.txt)"};
8  fs::path newPath{R"(C:\path\to\newname.txt)"};
9
10  try {
11    fs::rename(oldPath, newPath);
12    std::cout << "File renamed successfully";
13  } catch (const fs::filesystem_error& e) {
14    std::cerr << "Error: " << e.what();
15  }
16}

1File renamed successfully

Renaming a Directory

Similarly, you can rename a directory:

1#include <filesystem>
2#include <iostream>
3
4namespace fs = std::filesystem;
5
6int main() {
7  fs::path oldDir{R"(C:\path\to\olddir)"};
8  fs::path newDir{R"(C:\path\to\newdir)"};
9
10  try {
11    fs::rename(oldDir, newDir);
12    std::cout << "Directory renamed successfully";
13  } catch (const fs::filesystem_error& e) {
14    std::cerr << "Error: " << e.what();
15  }
16}

1Directory renamed successfully

Key Points

1. The rename() Function: Use std::filesystem::rename() to rename files or directories.
2. Exception Handling: Always use try-catch blocks to handle exceptions, as the function can throw errors if the operation fails.
3. Cross-Device Renaming: The rename() function may not work across different filesystems or devices. In such cases, use std::filesystem::copy() and std::filesystem::remove().

Error Handling

Proper error handling ensures your program can deal with scenarios where renaming fails:

1#include <filesystem>
2#include <iostream>
3
4namespace fs = std::filesystem;
5
6int main() {
7  fs::path oldPath{R"(C:\path\to\missing.txt)"};
8  fs::path newPath{R"(C:\path\to\new.txt)"};
9
10  try {
11    fs::rename(oldPath, newPath);
12    std::cout << "File renamed successfully";
13  } catch (const fs::filesystem_error& e) {
14    if (e.code() ==
15      std::errc::no_such_file_or_directory) {
16      std::cerr << "Error: File not found";
17    } else if (e.code() ==
18      std::errc::permission_denied) {
19      std::cerr << "Error: Permission denied";
20    } else {
21      std::cerr << "Error: " << e.what();
22    }
23  }
24}

1Error: File not found

Conclusion

Renaming files or directories with std::filesystem::path is simple and efficient using std::filesystem::rename(). Ensure you handle exceptions properly to create robust applications that manage file operations effectively.