< cpp‎ | experimental‎ | fs
Technical specifications
Filesystem library (filesystem TS)
Library fundamentals (library fundamentals TS)
Library fundamentals 2 (library fundamentals 2 TS)
Extensions for parallelism (parallelism TS)
Extensions for parallelism 2 (parallelism TS v2)
Extensions for concurrency (concurrency TS)
Concepts (concepts TS)
Ranges (ranges TS)
Special mathematical functions (special math TR)
Defined in header <experimental/filesystem>
std::uintmax_t hard_link_count( const path& p );
std::uintmax_t hard_link_count( const path& p, error_code& ec );
(1) (filesystem TS)

Returns the number of hard links for the filesystem object identified by path p.

The non-throwing overload returns static_cast<uintmax_t>(-1) on errors.


p - path to examine
ec - out-parameter for error reporting in the non-throwing overload

Return value

The number of hard links for p


The overload that does not take a 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 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:  


#include <iostream>
#include <experimental/filesystem>
namespace fs = std::experimental::filesystem;
int main()
    // On a POSIX-style filesystem, each directory has at least 2 hard links:
    // itself and the special member pathname "."
    fs::path p = fs::current_path();
    std::cout << "Number of hard links for current path is "
              << fs::hard_link_count(p) << '\n';
    // each ".." is a hard link to the parent directory, so the total number
    // of hard links for any directory is 2 plus number of direct subdirectories
    p = fs::current_path() / ".."; // each dot-dot is a hard link to parent
    std::cout << "Number of hard links for .. is "
              << fs::hard_link_count(p) << '\n';


Number of hard links for current path is 2
Number of hard links for .. is 3

See also

creates a hard link