std::filesystem::filesystem_error::what

 

C++

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Filesystem library(C++17)

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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::file_time_type filesystem::perms filesystem::perm_options filesystem::copy_options filesystem::directory_options
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::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
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

 

constchar* what()constnoexcept 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)

Return value

A C-stye explanatory byte string that contains the explanatory string passed at the time of construction.

Example

Run this code

#include <cstdio>#include <filesystem>#include <iostream>#include <string_view>namespace fs = std::filesystem;   void explain(std::string_view note, fs::filesystem_errorconst& 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_errorconst& ex){ explain("fs::rename()", ex);}   for(autoconst path :{"/bool", "/bin/cat", "/bin/mouse"})try{std::filesystem::create_directory(path);}catch(fs::filesystem_errorconst& ex){ explain("fs::create_directory()", ex);}}

Possible output:

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(): ""