std::experimental::filesystem:: status, std::experimental::filesystem:: symlink_status

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Defined in header `<experimental/filesystem>`
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 an error_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 an 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

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file_status	represents file type and permissions (class)
status_known	checks whether file status is known (function)
is_block_file	checks whether the given path refers to block device (function)
is_character_file	checks whether the given path refers to a character device (function)
is_directory	checks whether the given path refers to a directory (function)
is_fifo	checks whether the given path refers to a named pipe (function)
is_other	checks whether the argument refers to an other file (function)
is_regular_file	checks whether the argument refers to a regular file (function)
is_socket	checks whether the argument refers to a named IPC socket (function)
is_symlink	checks whether the argument refers to a symbolic link (function)
exists	checks whether path refers to existing file system object (function)
status symlink_status	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` )