std::filesystem::directory_entry::last_write_time
| 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
#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
| (C++17) |
gets or sets the time of the last data modification (function) |