std::filesystem::filesystem_error::what

 

C++

Compiler support

Freestanding and hosted

Language

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Technical specifications

Symbols index

External libraries

 

Filesystem library

Classes
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::perm_options filesystem::copy_options filesystem::directory_options filesystem::file_time_type
Functions
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::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
File types
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

Member functions

filesystem_error::filesystem_error

filesystem_error::operator=

filesystem_error::path1filesystem_error::path2

filesystem_error::what

Inherited from std::system_error

system_error::code

 

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

Returns an explanatory byte string. This explanatory string contains the explanatory string passed at the time of construction. Implementations are encouraged to include the pathnames of path1() and path2() in native format and the std::system_error::what() string inside the returned string as well.

Parameters

(none)

Example

Run this code

#include <cstdio>
#include <filesystem>
#include <iostream>
 
int main()
{
    try {
        std::filesystem::rename("/dev", "/null");
    }
    catch(std::filesystem::filesystem_error const& ex) {
        std::cout
            << "1) std::filesystem::rename():\n"
            << "what():  " << ex.what() << '\n'
            << "path1(): " << ex.path1() << '\n'
            << "path2(): " << ex.path2() << '\n';
    }
 
    try {
        std::filesystem::create_directory("/bool");
    }
    catch(std::filesystem::filesystem_error const& ex) {
        std::cout
            << "2) std::filesystem::create_directory():\n"
            << "what():  " << ex.what() << '\n'
            << "path1(): " << ex.path1() << '\n'
            << "path2(): " << ex.path2() << '\n';
    }
}

Possible output:

1) std::filesystem::rename():
what():  filesystem error: in rename: Permission denied [/dev] [/null]
path1(): "/dev"
path2(): "/null"
2) std::filesystem::create_directory():
what():  filesystem error: in create_directory: Permission denied [/bool]
path1(): "/bool"
path2(): ""