/**

 * Copyright (c) 2014-present, The osquery authors

 *

 * This source code is licensed as defined by the LICENSE file found in the

 * root directory of this source tree.

 *

 * SPDX-License-Identifier: (Apache-2.0 OR GPL-2.0-only)

 */

#include <osquery/utils/system/filepath.h>

#include <climits>

#include <cstdlib>

#include <cstring>

#include <string>

namespace osquery {

const std::string canonicalize_file_name(const char* name) {

#ifdef PATH_MAX

  // On supported platforms where PATH_MAX is defined we can pass null

  // as buffer, and allow libc to alloced space

  // On centos/ubuntu libc will use realloc so we will be able to resolve

  // any path

  // On darwin libc will allocate PATH_MAX buffer for us

  char* resolved = realpath(name, nullptr);

  std::string result = (resolved == nullptr) ? name : resolved;

  free(resolved);

#else

#warning PATH_MAX is undefined, please read comment below

  // PATH_MAX is not defined, very likely it's not officially supported

  // os, our best guess is _PC_PATH_MAX if available

  // In case of failure fallback to "safe" buffer of 8K

  long int path_max = pathconf(name, _PC_PATH_MAX);

  if (path_max <= 0) {

    path_max = 8 * 1024;

  }

  char* buffer = static_cast<char*>(malloc(path_max));

  char* resolved = realpath(name, buffer);

  std::string result = (resolved == nullptr) ? name : resolved;

  free(buffer);

#endif

  return result;

}

} // namespace osquery