std::filesystem::directory_entry::last_write_time
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< cpp | filesystem | directory entry
C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
std::filesystem::directory_entry
Member functions
Modifiers
Observers
directory_entry::last_write_time
(until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)
Non-member functions
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).
[edit] Parameters
ec
-
out-parameter for error reporting in the non-throwing overload
[edit] Return value
The last modification time for the referred-to filesystem object.
[edit] 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.
[edit] 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"