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.
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 |
#include <iostream> #include <fstream> #include <cstdio> #include <cstring> #include <filesystem> #include <unistd.h> #include <sys/socket.h> #include <sys/un.h> #include <sys/stat.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"); std::ofstream("sandbox/file"); // create regular file fs::create_directory("sandbox/dir"); 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); fs::create_symlink("file", "sandbox/symlink"); // 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 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
(C++17) | represents file type and permissions (class) |
(C++17) | checks whether the given path refers to block device (function) |
(C++17) | checks whether the given path refers to a character device (function) |
(C++17) | checks whether the given path refers to a directory (function) |
(C++17) | checks whether the given path refers to a named pipe (function) |
(C++17) | checks whether the argument refers to an other file (function) |
(C++17) | checks whether the argument refers to a named IPC socket (function) |
(C++17) | checks whether the argument refers to a symbolic link (function) |
checks whether the directory entry refers to a regular file (public member function of std::filesystem::directory_entry ) |
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