std::experimental::filesystem::file_time_type

 

C++

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技术规范

符号索引

外部库

 

实验性

技术规范

文件系统库 (文件系统 TS)

库基础 (库基础 TS)

库基础 2 (库基础 TS v2)

库基础 3 (库基础 TS v3)

并行扩展 (并行 TS)

并行扩展 2 (并行 TS v2)

并发扩展 (并发 TS)

并发扩展 2 (并发 TS v2)

概念 (概念 TS)

范围 (范围 TS)

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数学特殊函数 (特殊函数 TR)

实验性非 TS

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线性代数

std::execution

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2D 图形

 

文件系统库

类
filesystem::path filesystem::filesystem_error filesystem::directory_entry filesystem::directory_iterator filesystem::recursive_directory_iterator filesystem::file_status	filesystem::space_info filesystem::file_type filesystem::perms filesystem::copy_options filesystem::directory_options filesystem::file_time_type
函数
filesystem::absolute filesystem::system_complete filesystem::canonical filesystem::copy filesystem::copy_file filesystem::copy_symlink filesystem::create_directory filesystem::create_directories filesystem::create_hard_link filesystem::create_symlink filesystem::create_directory_symlink filesystem::current_path filesystem::exists filesystem::equivalent	filesystem::file_size filesystem::hard_link_count filesystem::last_write_time filesystem::permissions filesystem::read_symlink filesystem::remove filesystem::remove_all filesystem::rename filesystem::resize_file filesystem::space filesystem::status filesystem::symlink_status filesystem::temp_directory_path
文件类型
filesystem::is_block_file filesystem::is_character_file filesystem::is_directory filesystem::is_empty filesystem::status_known	filesystem::is_fifo filesystem::is_other filesystem::is_regular_file filesystem::is_socket filesystem::is_symlink

 

定义在头文件 <experimental/filesystem> 中
using file_time_type = chrono::time_point</*trivial-clock*/>;		(文件系统 TS)

表示文件时间。trivial-clock 是一个实现定义的类型，它满足 TrivialClock 并且足以表示文件系统提供的文件时间值的精度和范围。

示例

运行此代码

#include <chrono>
#include <experimental/filesystem>
#include <fstream>
#include <iomanip>
#include <iostream>
namespace fs = std::experimental::filesystem;
using namespace std::chrono_literals;
 
int main()
{
    fs::path p = fs::current_path() / "example.bin";
    std::ofstream(p.c_str()).put('a'); // create file
    auto ftime = fs::last_write_time(p);
 
    std::time_t cftime = decltype(ftime)::clock::to_time_t(ftime); // assuming system_clock
    std::cout << "File write time is " << std::asctime(std::localtime(&cftime)) << '\n';
 
    fs::last_write_time(p, ftime + 1h); // move file write time 1 hour to the future
    ftime = fs::last_write_time(p); // read back from the filesystem
 
    cftime = decltype(ftime)::clock::to_time_t(ftime);
    std::cout << "File write time is " << std::asctime(std::localtime(&cftime)) << '\n';
    fs::remove(p);
}

可能的输出

File write time is Tue Mar 31 19:47:04 2015
 
File write time is Tue Mar 31 20:47:04 2015

另请参见

last_write_time

获取或设置最后数据修改时间 (函数)