std::filesystem::read_symlink (3) - Linux Manuals

std::filesystem::read_symlink: std::filesystem::read_symlink

NAME

std::filesystem::read_symlink - std::filesystem::read_symlink

Synopsis

Defined in header <filesystem>
std::filesystem::path read_symlink(const std::filesystem::path& p);
std::filesystem::path read_symlink(const std::filesystem::path& p, (since C++17)
std::error_code& ec);

If the path p refers to a symbolic link, returns a new path object which refers to the target of that symbolic link.
It is an error if p does not refer to a symbolic link.
The non-throwing overload returns an empty path on errors.

Parameters

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

Return value

The target of the symlink (which may not necessarily exist)

Exceptions

The overload that does not take a std::error_code& parameter throws 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.

Example

// Run this code

  #include <iostream>
  #include <filesystem>

  namespace fs = std::filesystem;

  int main()
  {
      // on a typical Linux system, /lib/libc.so.6 is a symlink
      fs::path p = "/lib/libc.so.6";
      if(fs::exists(p) && fs::is_symlink(p))
          std::cout << p << " -> " << fs::read_symlink(p) << '\n';
      else
          std::cout << p << " does not exist or is not a symlink\n";
  }

Possible output:

  "/lib/libc.so.6" -> "libc-2.12.so"