Function getProjLibraryPath

src/proj_loader.cpp:105–130

Returns the path to the proj lib if lib exists, or optionally the path with the latest lib version in the directory

#if defined(__unix__) || defined(__APPLE__)
/// Returns the path to the proj lib if lib exists, or optionally the path with the latest lib version in the directory
std::string getProjLibraryPath(const std::string &dir, bool withLatestVersion = false) {
  std::regex projRegex(R"(libproj\.so(\.\d+)+$)"); 
  std::vector<std::string> candidates;

  if (!std::filesystem::exists(dir)) return "";

  for (const auto& entry : std::filesystem::directory_iterator(dir)) {
    try {
      std::string file = entry.path().filename().string();
      if (std::regex_match(file, projRegex)) {
        if (withLatestVersion == false) {
          return dir;
        }
        candidates.push_back(entry.path().string());
      }
    } catch (const std::filesystem::filesystem_error&) {
      continue;
    }
  }

  if (candidates.empty()) return "";

  // Sort by latest version (.so.22 / .so.25.2.1 etc.)
  std::sort(candidates.begin(), candidates.end());
  return candidates.back();  // latest version
}
#endif

/// Compare lib version numbers. Return ture if v1 latest version