Function CopyFile

FEXHeaderUtils/FEXHeaderUtils/Filesystem.h:185–231

* @brief Copy a file from a location to another * * Behaves similarly to std::filesystem::copy_file but with less copy options. * * @param From Source file location. * @param To Destination file location. * @param Options Copy options. * * @return True if the copy succeeded, false otherwise. */

 * @return True if the copy succeeded, false otherwise.
 */
inline bool CopyFile(const fextl::string& From, const fextl::string& To, CopyOptions Options = CopyOptions::NONE) {
  const bool DestExists = Exists(To);
  if (Options == CopyOptions::SKIP_EXISTING && DestExists) {
    // If the destination file exists already and the skip existing flag is set then
    // return true without error.
    return true;
  }

  if (Options == CopyOptions::OVERWRITE_EXISTING && DestExists) {
    // If we are overwriting and the file exists then we want to use `sendfile` to overwrite
    int SourceFD = open(From.c_str(), O_RDONLY | O_CLOEXEC);
    if (SourceFD == -1) {
      return false;
    }

    int DestinationFD = open(To.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0200);
    if (DestinationFD == -1) {
      close(SourceFD);
      return false;
    }

    struct stat buf;
    if (fstat(SourceFD, &buf) != 0) {
      close(DestinationFD);
      close(SourceFD);
      return false;
    }

    // Set the destination permissions to the original source permissions.
    if (fchmod(DestinationFD, buf.st_mode) != 0) {
      close(DestinationFD);
      close(SourceFD);
      return false;
    }
    bool Result = sendfile(DestinationFD, SourceFD, nullptr, buf.st_size) == buf.st_size;
    close(DestinationFD);
    close(SourceFD);
    return Result;
  }

  if (!DestExists) {
    // If the destination doesn't exist then just use rename.
    return rename(From.c_str(), To.c_str()) == 0;
  }

  return false;
}

inline fextl::string LexicallyNormal(const fextl::string& Path) {
  const auto PathSize = Path.size();