std::filesystem::directory_entry::refresh

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

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.

Example

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)