std::filesystem::recursive_directory_iterator (3) - Linux Manuals

std::filesystem::recursive_directory_iterator: std::filesystem::recursive_directory_iterator

NAME

std::filesystem::recursive_directory_iterator - std::filesystem::recursive_directory_iterator

Synopsis

Defined in header <filesystem>
class recursive_directory_iterator; (since C++17)

recursive_directory_iterator is an LegacyInputIterator that iterates over the directory_entry elements of a directory, and, recursively, over the entries of all subdirectories. The iteration order is unspecified, except that each directory entry is visited only once.
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 reports an error or is advanced past the last directory entry of the top-level directory, it becomes equal to the default-constructed iterator, also known as the end iterator. Two end iterators are always equal, dereferencing or incrementing the end iterator is undefined behavior.
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 type Definition
value_type std::filesystem::directory_entry
difference_type std::ptrdiff_t
pointer const std::filesystem::directory_entry*
reference const std::filesystem::directory_entry&
iterator_category std::input_iterator_tag

Member functions

                          constructs a recursive directory iterator
constructor (public member function)
                          default destructor
destructor (public member function)

Observers

                          accesses the pointed-to entry
operator* (public member function)
operator->
                          returns the currently active options that affect the iteration
options (public member function)
                          returns the current recursion depth
depth (public member function)
                          checks whether the recursion is disabled for the current directory
recursion_pending (public member function)

Modifiers

                          assigns contents
operator= (public member function)
                          advances to the next entry
increment (public member function)
operator++
                          moves the iterator one level up in the directory hierarchy
pop (public member function)
                          disables recursion until the next increment
disable_recursion_pending (public member function)

Non-member functions

                                                     range-based for loop support
begin(std::filesystem::recursive_directory_iterator) (function)
end(std::filesystem::recursive_directory_iterator)

Additionally, operator== and operator!= are provided, either as members or as non-members, as required by LegacyInputIterator

Notes

A recursive_directory_iterator typically holds a reference-counted pointer (to satisfy shallow-copy semantics of LegacyInputIterator) to an implementation object, which holds:

* a container (such as std::vector) of non-recursive directory_iterators that forms the recursion stack
* the recursion depth counter (accessible with depth())
* the directory options used at construction (accessible with options())
* the pending recursion flag (accessible with recursion_pending(), may be combined with the directory options to save space)

Example

// Run this code

  #include <fstream>
  #include <iostream>
  #include <filesystem>
  namespace fs = std::filesystem;

  int main()
  {
      fs::create_directories("sandbox/a/b");
      std::ofstream("sandbox/file1.txt");
      fs::create_symlink("a", "sandbox/syma");
      for(auto& p: fs::recursive_directory_iterator("sandbox"))
          std::cout << p.path() << '\n';
      fs::remove_all("sandbox");
  }

Possible output:

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