std::filesystem::directory_entry::refresh

From cppreference.com

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)
Diagnostics library
Memory management library
Metaprogramming library(C++11)
General utilities library
Containers library
Iterators library
Ranges library(C++20)
Algorithms library
Strings library
Text processing library
Numerics library
Date and time library
Input/output library
Filesystem library(C++17)
Concurrency support library(C++11)
Execution control library(C++26)
Technical specifications
Symbols index
External libraries

[edit]

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::file_time_type
filesystem::perms
filesystem::perm_options
filesystem::copy_options
filesystem::directory_options

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::temp_directory_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

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

[edit]

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<<

[edit]

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 withstatus,exists,is_regular_file, and other status accessors.

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

[edit]Parameters

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

[edit]Return value

(none)

[edit]Exceptions

Any overload not markednoexcept may throwstd::bad_alloc if memory allocation fails.

1) Throwsstd::filesystem::filesystem_error on underlying OS API errors, constructed withp as the first path argument and the OS error code as the error code argument.

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

[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 ofstd::filesystem::directory_iterator store these attributes, if any, in the pointed-tostd::filesystem::directory_entry without callingdirectory_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

This section is incomplete
Reason: no example

[edit]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)[edit]
exists	checks whether directory entry refers to existing file system object (public member function)[edit]
is_block_file	checks whether the directory entry refers to block device (public member function)[edit]
is_character_file	checks whether the directory entry refers to a character device (public member function)[edit]
is_directory	checks whether the directory entry refers to a directory (public member function)[edit]
is_fifo	checks whether the directory entry refers to a named pipe (public member function)[edit]
is_other	checks whether the directory entry refers to another file (public member function)[edit]
is_regular_file	checks whether the directory entry refers to a regular file (public member function)[edit]
is_socket	checks whether the directory entry refers to a named IPC socket (public member function)[edit]
is_symlink	checks whether the directory entry refers to a symbolic link (public member function)[edit]
file_size	returns the size of the file to which the directory entry refers (public member function)[edit]
hard_link_count	returns the number of hard links referring to the file to which the directory entry refers (public member function)[edit]
last_write_time	gets the time of the last data modification of the file to which the directory entry refers (public member function)[edit]