std::filesystem::hard_link_count - cppreference.com (original) (raw)
| Defined in header | ||
|---|---|---|
| std::uintmax_t hard_link_count( const std::filesystem::path& p ); | (1) | (since C++17) |
| std::uintmax_t hard_link_count( const std::filesystem::path& p, std::error_code& ec ) noexcept; | (2) | (since C++17) |
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.
[edit] Parameters
| p | - | path to examine |
|---|---|---|
| ec | - | out-parameter for error reporting in the non-throwing overload |
[edit] Return value
The number of hard links for p.
[edit] Exceptions
Any overload not marked noexcept may throw std::bad_alloc if memory allocation fails.
Throws std::filesystem::filesystem_error on underlying OS API errors, constructed with p as the first path argument and the OS error code as the error code argument.
Sets a std::error_code& parameter to the OS API error code if an OS API call fails, and executes ec.clear() if no errors occur.
[edit] Example
#include #include namespace fs = std::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'; }
Possible output:
Number of hard links for current path is 2 Number of hard links for .. is 3
[edit] See also
| | creates a hard link (function) [edit] | | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | returns the number of hard links referring to the file to which the directory entry refers (public member function of std::filesystem::directory_entry) [edit] |