std::filesystem::directory_entry::last_write_time
From cppreference.com
< cpp | filesystem | directory entry
| std::filesystem::file_time_type last_write_time() const; |
(1) | (since C++17) |
| std::filesystem::file_time_type last_write_time( std::error_code& ec ) const noexcept; |
(2) | (since C++17) |
If the last modification time is cached in this directory_entry, returns the cached value. Otherwise, returns:
1) std::filesystem::last_write_time(path()).
2) std::filesystem::last_write_time(path(), ec).
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
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.
Example
Run this code
#include <chrono> #include <ctime> #include <filesystem> #include <format> #include <iostream> #include <string> std::string to_string(const std::filesystem::file_time_type& ftime) { #if __cpp_lib_format return std::format("{:%c}", ftime); #else 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; #endif } 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:
Wed Sep 6 13:37:13.960314156 2023 : "main.cpp" Wed Sep 6 13:37:42.690271828 2023 : "a.out"
See also
| (C++17) |
gets or sets the time of the last data modification (function) |