std::experimental::filesystem::status, std::experimental::filesystem::symlink_status
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< cpp | experimental | fs
| Defined in header <experimental/filesystem>
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| file_status status( const path& p ); file_status status( const path& p, error_code& ec ) noexcept; |
(1) | (filesystem TS) |
| file_status symlink_status( const path& p ); file_status symlink_status( const path& p, error_code& ec ) noexcept; |
(2) | (filesystem TS) |
1) Determines the type and attributes of the filesystem object identified by p as if by POSIX stat (symlinks are followed to their targets).
- If p is a regular file, returns file_status(file_type::regular).
- If p is a directory, returns file_status(file_type::directory).
- If p is a block special file, returns file_status(file_type::block).
- If p is a character special file, returns file_status(file_type::character).
- If p is a fifo or pipe file, returns file_status(file_type::fifo).
- If p is a socket, returns file_status(file_type::socket).
- If p does not exist, returns file_status(file_type::not_found).
- If p exists but file attributes cannot be determined, e.g. due to lack of permissions, returns file_status(file_type::unknown).
- If errors prevent even knowing whether p exists, the non-throwing overload sets ec and returns file_status(file_type::none), and the throwing overload throws
filesystem_error. - Otherwise, returns file_status(file_type::unknown).
2) Same as (1) except that the behavior is as if the POSIX lstat is used (symlinks are not followed):
- If p is a symlink, returns file_status(file_type::symlink).
Parameters
| p | - | path to examine |
| ec | - | out-parameter for error reporting in the non-throwing overload |
Return value
The file status (a file_status object).
Exceptions
The overload that does not take aerror_code& parameter throws filesystem_error on underlying OS API errors, constructed with p as the first argument and the OS error code as the error code argument. std::bad_alloc may be thrown if memory allocation fails. The overload taking a error_code& parameter sets it to the OS API error code if an OS API call fails, and executes ec.clear() if no errors occur. This overload has noexcept specification:
noexcept
Notes
The information provided by this function is usually also provided as a byproduct of directory iteration, and may be obtained by the member functions of directory_entry. During directory iteration, calling status again is unnecessary.
Example
Run this code
#include <cstdio> #include <cstring> #include <experimental/filesystem> #include <fstream> #include <iostream> #include <sys/socket.h> #include <sys/stat.h> #include <sys/un.h> #include <unistd.h> namespace fs = std::experimental::filesystem; void demo_status(const fs::path& p, fs::file_status s) { std::cout << p; // alternative: switch(s.type()) { case fs::file_type::regular: ... } if (fs::is_regular_file(s)) std::cout << " is a regular file\n"; if (fs::is_directory(s)) std::cout << " is a directory\n"; if (fs::is_block_file(s)) std::cout << " is a block device\n"; if (fs::is_character_file(s)) std::cout << " is a character device\n"; if (fs::is_fifo(s)) std::cout << " is a named IPC pipe\n"; if (fs::is_socket(s)) std::cout << " is a named IPC socket\n"; if (fs::is_symlink(s)) std::cout << " is a symlink\n"; if (!fs::exists(s)) std::cout << " does not exist\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); struct 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, (struct 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
See also
| represents file type and permissions (class) | |
| checks whether file status is known (function) | |
| checks whether the given path refers to block device (function) | |
| checks whether the given path refers to a character device (function) | |
| checks whether the given path refers to a directory (function) | |
| checks whether the given path refers to a named pipe (function) | |
| checks whether the argument refers to an other file (function) | |
| checks whether the argument refers to a regular file (function) | |
| checks whether the argument refers to a named IPC socket (function) | |
| checks whether the argument refers to a symbolic link (function) | |
| checks whether path refers to existing file system object (function) | |
| cached status of the file designated by this directory entry cached symlink_status of the file designated by this directory entry (public member function of std::experimental::filesystem::directory_entry) |