std::filesystem::recursive_directory_iterator

recursive_directory_iterator is a LegacyInputIterator that iterates over the directory_entry

By default, symlinks are not followed, but this can be enabled by specifying the directory option follow_directory_symlink at construction time.

The special pathnames dot and dot-dot are skipped.

If the recursive_directory_iterator

If a file or a directory is deleted or added to the directory tree after the recursive directory iterator has been created, it is unspecified whether the change would be observed through the iterator.

If the directory structure contains cycles, the end iterator may be unreachable.

Member types

Member functions

Non-member functions

Additionally, operator== and operator!= are(until C++20) operator== is(since C++20) provided as required by LegacyInputIterator

It is unspecified whether operator!= is provided because it can be synthesized from operator==, and (since C++20)

Helper specializations

These specializations for recursive_directory_iterator make it a borrowed_range and a view

Notes

A recursive_directory_iterator typically holds a reference-counted pointer (to satisfy shallow-copy semantics of LegacyInputIterator

• a container (such as std::vector) of non-recursive directory_iterators
• the recursion depth counter (accessible with depth()),
• the directory options used at construction (accessible with options()),
• the pending recursion flag (accessible with recursion_pending()

Example

#include <filesystem>
#include <fstream>
#include <iostream>
#include <string>
namespace fs = std::filesystem;
 
int main()
{
    std::filesystem::current_path(std::filesystem::temp_directory_path());
    std::filesystem::create_directories("sandbox/a/b");
    std::ofstream("sandbox/file1.txt");
    std::filesystem::create_symlink("a", "sandbox/syma");
 
    // Iterate over the std::filesystem::directory_entry elements explicitly
    auto entry_length{3UZ};
    for (const fs::directory_entry& dir_entry :
            fs::recursive_directory_iterator("sandbox"))
    {
        std::cout << dir_entry << '\n';
        if (auto l{dir_entry.path().string().length()}; entry_length < l)
            entry_length = l;
    }
    std::cout << std::string(entry_length + 2, '-') << '\n';
 
    // Iterate over the std::filesystem::directory_entry elements using `auto`
    for (auto const& dir_entry : fs::recursive_directory_iterator("sandbox"))
        std::cout << dir_entry << '\n';
 
    std::filesystem::remove_all("sandbox");
}

"sandbox/syma"
"sandbox/file1.txt"
"sandbox/a"
"sandbox/a/b"
-------------------
"sandbox/syma"
"sandbox/file1.txt"
"sandbox/a"
"sandbox/a/b"

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

See also