std::filesystem::filesystem_error::what

 

C++

编译器支持

独立式和宿主式

语言

标准库

标准库头文件

具名要求

特性测试宏 (C++20)

语言支持库

概念库 (C++20)

诊断库

内存管理库

元编程库 (C++11)

通用工具库

容器库

迭代器库

范围库 (C++20)

算法库

字符串库

文本处理库

数值库

日期和时间库

输入/输出库

文件系统库 (C++17)

并发支持库 (C++11)

执行控制库 (C++26)

技术规范

符号索引

外部库

 

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::file_time_type filesystem::perms filesystem::perm_options filesystem::copy_options filesystem::directory_options
函数
filesystem::absolute filesystem::canonicalfilesystem::weakly_canonical filesystem::relativefilesystem::proximate 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::temp_directory_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
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

 

filesystem_error

成员函数

filesystem_error::filesystem_error

filesystem_error::operator=

filesystem_error::path1filesystem_error::path2

filesystem_error::what

继承自 std::system_error

system_error::code

 

const char* what() const noexcept override;		(since C++17)

返回一个解释性字节字符串。此解释性字符串包含构造时传递的解释性字符串。鼓励实现包括 path1() 和 path2() 的路径名（以本机格式）以及 std::system_error::what() 字符串（在返回的字符串中）。

参数

(无)

返回值

一个 C 风格的解释性字节字符串，其中包含构造时传递的解释性字符串。

示例

运行此代码

#include <cstdio>
#include <filesystem>
#include <iostream>
#include <string_view>
namespace fs = std::filesystem;
 
void explain(std::string_view note, fs::filesystem_error const& ex)
{
    std::cout << note << " exception:\n"
              << "what(): " << ex.what() << '\n'
              << "path1(): " << ex.path1() << ", path2(): "
              << ex.path2() << "\n\n";
}
 
int main()
{
    try
    {
        std::filesystem::rename("/dev", "/null");
    }
    catch(fs::filesystem_error const& ex)
    {
        explain("fs::rename()", ex);
    }
 
    for (auto const path : {"/bool", "/bin/cat", "/bin/mouse"})
        try
        {
            std::filesystem::create_directory(path);
        }
        catch(fs::filesystem_error const& ex)
        {
            explain("fs::create_directory()", ex);
        }
}

可能的输出

fs::rename() exception:
what(): filesystem error: cannot rename: Permission denied [/dev] [/null]
path1(): "/dev", path2(): "/null"
 
fs::create_directory() exception:
what(): filesystem error: cannot create directory: Permission denied [/bool]
path1(): "/bool", path2(): ""
 
fs::create_directory() exception:
what(): filesystem error: cannot create directory: File exists [/bin/cat]
path1(): "/bin/cat", path2(): ""
 
fs::create_directory() exception:
what(): filesystem error: cannot create directory: Read-only file system [/bin/mouse]
path1(): "/bin/mouse", path2(): ""