# std::filesystem::directory_entry::last_write_time

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< cpp‎ | filesystem‎ | directory entry

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

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"

### See also

last_write_time (C++17) | gets or sets the time of the last data modification (function)

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