std::filesystem::file_type

 

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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

 

Defined in header <filesystem>
enum class file_type {     none = /* unspecified */,     not_found = /* unspecified */,     regular = /* unspecified */,     directory = /* unspecified */,     symlink = /* unspecified */,     block = /* unspecified */,     character = /* unspecified */,     fifo = /* unspecified */,     socket = /* unspecified */,     unknown = /* unspecified */,     /* implementation-defined */ };		(since C++17)

file_type defines constants that indicate a type of a file or directory a path refers to. The value of the enumerators are distinct.

Constants

Constant	Meaning
none	indicates that the file status has not been evaluated yet, or an error occurred when evaluating it
not_found	indicates that the file was not found (this is not considered an error)
regular	a regular file
directory	a directory
symlink	a symbolic link
block	a block special file
character	a character special file
fifo	a FIFO (also known as pipe) file
socket	a socket file
implementation-defined	an additional implementation-defined constant for each additional file type supported by the implementation (e.g. MSVC STL defines junction for NTFS junctions)
unknown	the file exists but its type could not be determined

Example

Run this code

#include <cstdio>
#include <cstring>
#include <filesystem>
#include <fstream>
#include <iostream>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <unistd.h>
 
namespace fs = std::filesystem;
 
void demo_status(const fs::path& p, fs::file_status s)
{
    std::cout << p;
    switch (s.type())
    {
        case fs::file_type::none:
            std::cout << " has `not-evaluated-yet` type";
            break;
        case fs::file_type::not_found:
            std::cout << " does not exist";
            break;
        case fs::file_type::regular:
            std::cout << " is a regular file";
            break;
        case fs::file_type::directory:
            std::cout << " is a directory";
            break;
        case fs::file_type::symlink:
            std::cout << " is a symlink";
            break;
        case fs::file_type::block:
            std::cout << " is a block device";
            break;
        case fs::file_type::character:
            std::cout << " is a character device";
            break;
        case fs::file_type::fifo:
            std::cout << " is a named IPC pipe";
            break;
        case fs::file_type::socket:
            std::cout << " is a named IPC socket";
            break;
        case fs::file_type::unknown:
            std::cout << " has `unknown` type";
            break;
        default:
            std::cout << " has `implementation-defined` type";
            break;
    }
    std::cout << '\n';
}
 
int main()
{
    // create files of different kinds
    fs::create_directory("sandbox");
    fs::create_directory("sandbox/dir");
    std::ofstream{"sandbox/file"}; // create regular file
    fs::create_symlink("file", "sandbox/symlink");
 
    mkfifo("sandbox/pipe", 0644);
    sockaddr_un addr;
    addr.sun_family = AF_UNIX;
    std::strcpy(addr.sun_path, "sandbox/sock");
    int fd = socket(PF_UNIX, SOCK_STREAM, 0);
    bind(fd, reinterpret_cast<sockaddr*>(&addr), sizeof addr);
 
    // demo different status accessors
    for (auto it{fs::directory_iterator("sandbox")}; it != fs::directory_iterator(); ++it)
        demo_status(*it, it->symlink_status()); // use cached status from directory entry
    demo_status("/dev/null", fs::status("/dev/null")); // direct calls to status
    demo_status("/dev/sda", fs::status("/dev/sda"));
    demo_status("sandbox/no", fs::status("/sandbox/no"));
 
    // cleanup (prefer std::unique_ptr-based custom deleters)
    close(fd);
    fs::remove_all("sandbox");
}

Possible output:

"sandbox/file" is a regular file
"sandbox/dir" is a directory
"sandbox/pipe" is a named IPC pipe
"sandbox/sock" is a named IPC socket
"sandbox/symlink" is a symlink
"/dev/null" is a character device
"/dev/sda" is a block device
"sandbox/no" does not exist

See also

file_status (C++17)	represents file type and permissions (class)
is_block_file (C++17)	checks whether the given path refers to block device (function)
is_character_file (C++17)	checks whether the given path refers to a character device (function)
is_directory (C++17)	checks whether the given path refers to a directory (function)
is_fifo (C++17)	checks whether the given path refers to a named pipe (function)
is_other (C++17)	checks whether the argument refers to an other file (function)
is_socket (C++17)	checks whether the argument refers to a named IPC socket (function)
is_symlink (C++17)	checks whether the argument refers to a symbolic link (function)
is_regular_file	checks whether the directory entry refers to a regular file (public member function of std::filesystem::directory_entry)