Function extract

src/launcher/fetcher.cpp:67–136

Try to extract sourcePath into directory. If sourcePath is recognized as an archive it will be extracted and true returned; if not recognized then false will be returned. An Error is returned if the extraction command fails.

// if not recognized then false will be returned. An Error is
// returned if the extraction command fails.
static Try<bool> extract(
    const string& sourcePath,
    const string& destinationDirectory)
{
  Try<Nothing> result = Nothing();

  Option<Subprocess::IO> in = None();
  Option<Subprocess::IO> out = None();
  vector<string> command;

  // Extract any .tar, .tgz, tar.gz, tar.bz2 or zip files.
  if (strings::endsWith(sourcePath, ".tar") ||
      strings::endsWith(sourcePath, ".tgz") ||
      strings::endsWith(sourcePath, ".tar.gz") ||
      strings::endsWith(sourcePath, ".tbz2") ||
      strings::endsWith(sourcePath, ".tar.bz2") ||
      strings::endsWith(sourcePath, ".txz") ||
      strings::endsWith(sourcePath, ".tar.xz") ||
      strings::endsWith(sourcePath, ".zip")) {
    Try<Nothing> result = archiver::extract(sourcePath, destinationDirectory);
    if (result.isError()) {
      return Error(
          "Failed to extract archive '" + sourcePath +
          "' to '" + destinationDirectory + "': " + result.error());
    }
    return true;
  } else if (strings::endsWith(sourcePath, ".gz")) {
    // Unfortunately, libarchive can't extract bare files, so leave this to
    // the 'gunzip' program, if it exists.
    string pathWithoutExtension = sourcePath.substr(0, sourcePath.length() - 3);
    string filename = Path(pathWithoutExtension).basename();
    string destinationPath = path::join(destinationDirectory, filename);

    command = {"gunzip", "-d", "-c"};
    in = Subprocess::PATH(sourcePath);
    out = Subprocess::PATH(destinationPath);
  } else {
    return false;
  }

  CHECK_GT(command.size(), 0u);

  Try<Subprocess> extractProcess = subprocess(
      command[0],
      command,
      in.getOrElse(Subprocess::PATH(os::DEV_NULL)),
      out.getOrElse(Subprocess::FD(STDOUT_FILENO)),
      Subprocess::FD(STDERR_FILENO));

  if (extractProcess.isError()) {
    return Error(
        "Failed to extract '" + sourcePath + "': '" +
        strings::join(" ", command) + "' failed: " +
        extractProcess.error());
  }

  // `status()` never fails or gets discarded.
  int status = extractProcess->status()->get();