Defined in header <filesystem> | ||
|---|---|---|
std::uintmax_t hard_link_count( const std::filesystem::path& p );
std::uintmax_t hard_link_count( const std::filesystem::path& p,
std::error_code& ec ) noexcept;
| (1) | (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.
| p | - | path to examine |
| ec | - | out-parameter for error reporting in the non-throwing overload |
The number of hard links for p.
The overload that does not take a std::error_code& parameter throws 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. The overload taking a std::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. Any overload not marked noexcept may throw std::bad_alloc if memory allocation fails.
#include <iostream>
#include <filesystem>
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
|
(C++17) | creates a hard link (function) |
| returns the number of hard links referring to the file to which the directory entry refers (public member function of std::filesystem::directory_entry) |
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