NAME

std::filesystem::directory_entry::last_write_time - std::filesystem::directory_entry::last_write_time

Synopsis

std::filesystem::file_time_type last_write_time() const;
std::filesystem::file_time_type last_write_time( std::error_code& ec (since C++17)
) const noexcept;

If the last modification time is cached in this directory_entry, returns the cached
value. Otherwise, returns std::filesystem::last_write_time(path()) or
std::filesystem::last_write_time(path(), ec), respectively.

Parameters

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

Return value

The last modification time for the referred-to filesystem object

Exceptions

The overload that does not take a std::error_code& parameter throws
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. The overload
taking a std::error_code& parameter sets it to the OS API error code if an OS API
call fails, and executes ec.clear() if no errors occur. Any overload not marked
noexcept may throw std::bad_alloc if memory allocation fails.

Example

// Run this code

#include <filesystem>
#include <iostream>
#include <string>
#include <chrono>
#include <ctime>

std::string to_string(std::filesystem::file_time_type const& ftime) {
std::time_t cftime = std::chrono::system_clock::to_time_t(
std::chrono::file_clock::to_sys(ftime));
std::string str = std::asctime(std::localtime(&cftime));
str.pop_back(); // rm the trailing '\n' put by `asctime`
return str;
}

int main() {
auto dir = std::filesystem::current_path();
using Entry = std::filesystem::directory_entry;
for (Entry const& entry : std::filesystem::directory_iterator(dir)) {
std::cout << to_string(entry.last_write_time())
<< " : " << entry.path().filename() << '\n';
}
}

Possible output:

Sat Aug 21 07:39:13 2021 : "main.cpp"
Sat Aug 21 07:39:16 2021 : "a.out"