List Files in Directory

To list all files in a directory using std::filesystem, you can use the std::filesystem::directory_iterator. This iterator allows you to iterate over the contents of a directory, providing access to each directory_entry.

Here's a simple example demonstrating how to list all files and directories in a specified path:

1#include <filesystem>
2#include <iostream>
3namespace fs = std::filesystem;
4
5int main() {
6  fs::path dir_path{R"(c:\test)"};  
7  try {
8    for (const auto &entry
9      : fs::directory_iterator(dir_path)) {
10      std::cout << entry.path().string() << '\n';  
11    }
12  } catch (fs::filesystem_error &e) {
13    std::cerr << e.what() << '\\n';
14  }
15}

1c:\test\file1.txt
2c:\test\file2.txt
3c:\test\subdir

In this example:

• We define dir_path as the path to the directory we want to list.
• We use a for loop to iterate over each entry in the directory using fs::directory_iterator.
• The entry.path() method retrieves the path of each file and directory, and we can create a std::string() from this object using the string() method.

You should include error handling because std::filesystem operations can throw exceptions, particularly if the directory does not exist or there are permission issues. The try block and catch block handle any fs::filesystem_error exceptions and print the error message.

This approach lists both files and directories. If you want to filter out directories and list only files, you can use the is_regular_file() method:

1#include <filesystem>
2#include <iostream>
3
4namespace fs = std::filesystem;
5
6int main() {
7  fs::path dir_path{R"(c:\test)"};  
8  try {
9    for (const auto &entry
10      : fs::directory_iterator(dir_path)) {
11      if (fs::is_regular_file(entry.status())) {  
12        std::cout << entry.path().string() << '\n';
13      }
14    }
15  } catch (fs::filesystem_error &e) {
16    std::cerr << e.what() << '\n';
17  }
18}

1c:\test\file1.txt
2c:\test\file2.txt

In this updated example, the if statement checks if the current entry is a regular file before printing its path.