std::filesystem::directory_iterator
Defined in header <filesystem> | ||
|---|---|---|
class directory_iterator; | (since C++17) |
directory_iterator is a LegacyInputIterator 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 reports an error or 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.
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 directory iterator (public member function) |
|
| (destructor) | default destructor (public member function) |
| assigns contents (public member function) |
|
| accesses the pointed-to entry (public member function) |
|
| advances to the next entry (public member function) |
Non-member functions
| range-based for loop support (function) |
Additionally, operator== and operator!= are provided, either as members or as non-members, as required by LegacyInputIterator.
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.
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.path() << '\n';
fs::remove_all("sandbox");
}Possible output:
"sandbox/a" "sandbox/file1.txt" "sandbox/file2.txt"
See also
|
(C++17) | an iterator to the contents of a directory and its subdirectories (class) |
|
(C++17) | options for iterating directory contents (enum) |
|
(C++17) | a directory entry (class) |
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