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std::filesystem::directory_iterator

From cppreference.com
 
 
 
 
Defined in header <filesystem>
class directory_iterator;
(since C++17)

directory_iterator is an InputIterator that iterates over the directory_entry elements of a directory (but does not visit the subdirectories). The iteration order is unspecified, except that each directory entry is visited only once. The special pathnames dot and dot-dot are skipped.

If the directory_iterator is advanced past the last directory entry, 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 directory iterator has been created, it is unspecified whether the change would be observed through the iterator.

Contents

[edit] 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

[edit] Member functions

constructs a directory iterator
(public member function) [edit]
(destructor)
default destructor
(public member function) [edit]
assigns contents
(public member function) [edit]
accesses the pointed-to entry
(public member function) [edit]
advances to the next entry
(public member function) [edit]

[edit] Non-member functions

range-based for loop support
(function) [edit]

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

[edit] Notes

Many low-level OS APIs for directory traversal retrieve file attributes along with the next directory entry. The constructors and the non-const member functions of directory_iterator store these attributes, if any, in the pointed-to directory_entry without calling directory_entry::refresh, which makes it possible to examine the attributes of the directory entries as they are being iterated over, without making additional system calls.

[edit] Example

#include <fstream>
#include <iostream>
#include <filesystem>
namespace fs = std::filesystem;
 
int main()
{
    fs::create_directories("sandbox/a/b");
    std::ofstream("sandbox/file1.txt");
    std::ofstream("sandbox/file2.txt");
    for(auto& p: fs::directory_iterator("sandbox"))
        std::cout << p << '\n';
    fs::remove_all("sandbox");
}

Possible output:

"sandbox/a"
"sandbox/file1.txt"
"sandbox/file2.txt"

[edit] See also

an iterator to the contents of a directory and its subdirectories
(class) [edit]
options for iterating directory contents
(enum) [edit]
a directory entry
(class) [edit]