std::filesystem::directory_entry::refresh

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Execution support library (C++26)

Technical specifications

Symbols index

External libraries

 

Filesystem library

Classes
filesystem::path filesystem::filesystem_error filesystem::directory_entry filesystem::directory_iterator filesystem::recursive_directory_iterator      filesystem::file_status	filesystem::space_info filesystem::file_type filesystem::perms filesystem::perm_options filesystem::copy_options filesystem::directory_options filesystem::file_time_type
Functions
filesystem::absolute filesystem::canonicalfilesystem::weakly_canonical filesystem::relativefilesystem::proximate filesystem::copy filesystem::copy_file filesystem::copy_symlink filesystem::create_directory filesystem::create_directories filesystem::create_hard_link filesystem::create_symlink filesystem::create_directory_symlink filesystem::current_path	filesystem::exists filesystem::equivalent filesystem::file_size filesystem::hard_link_count filesystem::last_write_time filesystem::permissions filesystem::read_symlink filesystem::remove filesystem::remove_all filesystem::rename filesystem::resize_file filesystem::space filesystem::status filesystem::symlink_status filesystem::temp_directory_path
File types
filesystem::is_block_file filesystem::is_character_file filesystem::is_directory filesystem::is_empty filesystem::status_known	filesystem::is_fifo filesystem::is_other filesystem::is_regular_file filesystem::is_socket filesystem::is_symlink

 

std::filesystem::directory_entry

Member functions

directory_entry::directory_entry

Modifiers

directory_entry::operator=

directory_entry::assign

directory_entry::replace_filename

directory_entry::refresh

Observers

directory_entry::pathdirectory_entry::operator const path&

directory_entry::exists

directory_entry::is_block_file

directory_entry::is_character_file

directory_entry::is_directory

directory_entry::is_fifo

directory_entry::is_other

directory_entry::is_regular_file

directory_entry::is_socket

directory_entry::is_symlink

directory_entry::file_size

directory_entry::hard_link_count

directory_entry::last_write_time

directory_entry::statusdirectory_entry::symlink_status

directory_entry::operator==directory_entry::operator!=directory_entry::operator<directory_entry::operator>directory_entry::operator<=directory_entry::operator>=directory_entry::operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)

Non-member functions

operator<<

 

void refresh();	(1)	(since C++17)
void refresh( std::error_code& ec ) noexcept;	(2)	(since C++17)

Examines the filesystem object referred to by this directory entry and stores its attributes for retrieval with status, exists, is_regular_file, and other status accessors.

If an error occurs, the value of any cached attributes is unspecified.

Parameters

ec

-

out-parameter for error reporting in the non-throwing overload

Return value

(none)

Exceptions

Any overload not marked noexcept may throw std::bad_alloc if memory allocation fails.

1) Throws std::filesystem::filesystem_error on underlying OS API errors, constructed with p as the first path argument and the OS error code as the error code argument.

2) Sets a std::error_code& parameter to the OS API error code if an OS API call fails, and executes ec.clear() if no errors occur.

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 std::filesystem::directory_iterator store these attributes, if any, in the pointed-to std::filesystem::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.

See also

statussymlink_status	status of the file designated by this directory entry; status of the file/symlink designated by this directory entry (public member function)
exists	checks whether directory entry refers to existing file system object (public member function)
is_block_file	checks whether the directory entry refers to block device (public member function)
is_character_file	checks whether the directory entry refers to a character device (public member function)
is_directory	checks whether the directory entry refers to a directory (public member function)
is_fifo	checks whether the directory entry refers to a named pipe (public member function)
is_other	checks whether the directory entry refers to an other file (public member function)
is_regular_file	checks whether the directory entry refers to a regular file (public member function)
is_socket	checks whether the directory entry refers to a named IPC socket (public member function)
is_symlink	checks whether the directory entry refers to a symbolic link (public member function)
file_size	returns the size of the file to which the directory entry refers (public member function)
hard_link_count	returns the number of hard links referring to the file to which the directory entry refers (public member function)
last_write_time	gets the time of the last data modification of the file to which the directory entry refers (public member function)