def install(self):
        # get content type.
        if is_file(self.download_url):
            path = fileurl_to_path(self.download_url)
            self.content_type = mimetypes.guess_type(path)[0]
        else:
            headerinfo = Downloader.read_head_info(self.download_url)
            self.content_type = headerinfo['content-type']
        if is_html(self.content_type):
            # note: maybe got 404 or 503 http status code.
            logger.error("Invalid content-type: `%s`" % self.content_type)
            return

        if os.path.isdir(self.install_dir):
            logger.info("You have already installed `%s`" % self.pkg.name)
            return

        self.download_and_extract()
        logger.info("\nThis could take a while. You can run the following command on another shell to track the status:")
        logger.info("  tail -f %s\n" % self.logfile)
        logger.info("Installing %s into %s" % (self.pkg.name, self.install_dir))
        try:
            self.patch()
            self.configure()
            self.make()
            self.make_install()
        except Exception:
            import traceback
            traceback.print_exc()
            rm_r(self.install_dir)
            logger.error("Failed to install %s. Check %s to see why." % (self.pkg.name, self.logfile))
            sys.exit(1)
        self.symlink()
        logger.info("\nInstalled %(pkgname)s successfully." % {"pkgname": self.pkg.name})

    def install(self):
        # cleanup
        if os.path.isdir(self.build_dir):
            shutil.rmtree(self.build_dir)

        # get content type.
        if is_file(self.download_url):
            path = fileurl_to_path(self.download_url)
            self.content_type = mimetypes.guess_type(path)[0]
        else:
            headerinfo = Downloader.read_head_info(self.download_url)
            self.content_type = headerinfo['content-type']
        if is_html(self.content_type):
            # note: maybe got 404 or 503 http status code.
            logger.error("Invalid content-type: `%s`" % self.content_type)
            return

        if os.path.isdir(self.install_dir):
            logger.info("You have already installed `%s`" % self.pkg.name)
            return

        self.download_and_extract()
        logger.info("\nThis could take a while. You can run the following command on another shell to track the status:")
        logger.info("  tail -f %s\n" % self.logfile)
        logger.info("Installing %s into %s" % (self.pkg.name, self.install_dir))
        shutil.copytree(self.build_dir, self.install_dir)
        self.symlink()
        logger.info("\nInstalled %(pkgname)s successfully." % {"pkgname": self.pkg.name})

 def _update_pythonz(self, options, args):
     download_url = PYTHONZ_UPDATE_URL
     headinfo = get_headerinfo_from_url(download_url)
     content_type = headinfo['content-type']
     filename = "pythonz-latest"
     distname = "%s.tgz" % filename
     download_file = os.path.join(PATH_DISTS, distname)
     # Remove old tarball
     unlink(download_file)
     try:
         d = Downloader()
         d.download(distname, download_url, download_file)
     except:
         logger.error("Failed to download. `%s`" % download_url)
         sys.exit(1)
     
     extract_dir = os.path.join(PATH_BUILD, filename)
     rm_r(extract_dir)
     if not extract_downloadfile(content_type, download_file, extract_dir):
         sys.exit(1)
     
     try:
         logger.info("Installing %s into %s" % (extract_dir, ROOT))
         s = Subprocess()
         s.check_call([sys.executable, os.path.join(extract_dir,'pythonz_install.py'), '--upgrade'])
     except:
         logger.error("Failed to update pythonz.")
         sys.exit(1)
     logger.info("The pythonz has been updated.")

def extract_downloadfile(content_type, download_file, target_dir):
    logger.info("Extracting %s into %s" % (os.path.basename(download_file), target_dir))
    if is_gzip(content_type, download_file):
        untar_file(download_file, target_dir)
    else:
        logger.error("Cannot determine archive format of %s" % download_file)
        return False
    return True

 def download(self):
     if os.path.isfile(self.download_file) and sha256(self.download_file) == self.expected_sha256:
         logger.info("Use the previously fetched %s" % (self.download_file))
     else:
         base_url = Link(self.download_url).base_url
         logger.info("Downloading %s as %s" % (base_url, self.download_file))
         try:
             Downloader.fetch(self.download_url, self.download_file, self.expected_sha256)
         except DownloadError:
             logger.error("Failed to download.\n%s" % (sys.exc_info()[1]))
             sys.exit(1)

    def install(self):
        # check if java is installed
        r = subprocess.call("command -v java > /dev/null", shell=True)
        if r != 0:
            logger.error("Jython requires Java to be installed, but the 'java' command was not found in the path.")
            return

        # get content type.
        if is_file(self.download_url):
            path = fileurl_to_path(self.download_url)
            self.content_type = mimetypes.guess_type(path)[0]
        else:
            try:
                headerinfo = Downloader.read_head_info(self.download_url)
            except DownloadError:
                self.content_type = None
            else:
                self.content_type = headerinfo['content-type']
        if is_html(self.content_type):
            # note: maybe got 404 or 503 http status code.
            logger.error("Invalid content-type: `%s`" % self.content_type)
            return

        self.download()
        logger.info("\nThis could take a while. You can run the following command on another shell to track the status:")
        logger.info("  tail -f %s\n" % self.logfile)
        logger.info("Installing %s into %s" % (self.pkg.name, self.install_dir))
        cmd = 'java -jar %s -s -d %s' % (self.download_file, self.install_dir)
        s = Subprocess(log=self.logfile, verbose=self.options.verbose)
        s.check_call(cmd)
        self.symlink()
        logger.info("\nInstalled %(pkgname)s successfully." % {"pkgname": self.pkg.name})

 def run_command(self, options, args):
     if not args:
         self.parser.print_help()
         sys.exit(1)
     for arg in args:
         try:
             p = PythonInstaller.get_installer(arg, options)
             p.install()
         except AlreadyInstalledError as e:
             logger.info(e)
         except Exception:
             import traceback
             traceback.print_exc()
             continue

 def download(self):
     if os.path.isfile(self.download_file):
         logger.info("Use the previously fetched %s" % (self.download_file))
     else:
         base_url = Link(self.download_url).base_url
         logger.info("Downloading %s as %s" % (base_url, self.download_file))
         try:
             Downloader.fetch(self.download_url, self.download_file)
         except DownloadError:
             unlink(self.download_file)
             logger.error("Failed to download.\n%s" % (sys.exc_info()[1]))
             sys.exit(1)
         except:
             unlink(self.download_file)
             raise

    def run_command(self, options, args):
        if not args:
            self.parser.print_help()
            sys.exit(1)
        pkg = Package(args[0], options.type)
        pkgname = pkg.name
        pkgdir = os.path.join(PATH_PYTHONS, pkgname)
        if not os.path.isdir(pkgdir):
            logger.error("`%s` is not installed." % pkgname)
            sys.exit(1)
        pkgbin = os.path.join(pkgdir,'bin')

        self._set_temp(pkgbin)

        logger.info("Using `%s`" % pkgname)

 def _update_config(self, options, args):
     # config.cfg update
     # TODO: Automatically create for config.cfg
     download_url = PYTHONZ_UPDATE_URL_CONFIG
     if not download_url:
         logger.error("Invalid download url in config.cfg. `%s`" % download_url)
         sys.exit(1)
     distname = Link(PYTHONZ_UPDATE_URL_CONFIG).filename
     download_file = PATH_ETC_CONFIG
     logger.info("Downloading %s as %s" % (distname, download_file))
     try:
         Downloader.fetch(download_url, download_file)
     except DownloadError:
         logger.error("Failed to download. `%s`" % download_url)
         sys.exit(1)
     logger.log("The config.cfg has been updated.")

 def download_and_extract(self):
     if is_file(self.download_url):
         path = fileurl_to_path(self.download_url)
         if os.path.isdir(path):
             logger.info('Copying %s into %s' % (path, self.build_dir))
             shutil.copytree(path, self.build_dir)
             return
     if os.path.isfile(self.download_file):
         logger.info("Use the previously fetched %s" % (self.download_file))
     else:
         base_url = Link(self.download_url).base_url
         try:
             dl = Downloader()
             dl.download(base_url, self.download_url, self.download_file)
         except:
             unlink(self.download_file)
             logger.error("Failed to download.\n%s" % (sys.exc_info()[1]))
             sys.exit(1)
     # extracting
     if not extract_downloadfile(self.content_type, self.download_file, self.build_dir):
         sys.exit(1)

    def run_command(self, options, args):
        headinfo = Downloader.read_head_info(PYTHONZ_UPDATE_URL)
        content_type = headinfo["content-type"]
        filename = "pythonz-latest"
        distname = "%s.tgz" % filename
        download_file = os.path.join(PATH_DISTS, distname)
        # Remove old tarball
        unlink(download_file)
        logger.info("Downloading %s as %s" % (distname, download_file))
        try:
            Downloader.fetch(PYTHONZ_UPDATE_URL, download_file)
        except DownloadError:
            unlink(download_file)
            logger.error("Failed to download. `%s`" % PYTHONZ_UPDATE_URL)
            sys.exit(1)
        except:
            unlink(download_file)
            raise

        extract_dir = os.path.join(PATH_BUILD, filename)
        rm_r(extract_dir)
        if not extract_downloadfile(content_type, download_file, extract_dir):
            sys.exit(1)

        try:
            logger.info("Installing %s into %s" % (extract_dir, ROOT))
            s = Subprocess()
            s.check_call([sys.executable, os.path.join(extract_dir, "pythonz_install.py"), "--upgrade"])
        except:
            logger.error("Failed to update pythonz.")
            sys.exit(1)
        logger.info("pythonz has been updated.")

 def download(self, msg, url, path):
     logger.info("Downloading %s as %s" % (msg, path))
     c = get_concrete_downloader()
     c.fetch(url, path)

 def download(self, msg, url, path):
     logger.info("Downloading %s as %s" % (msg, path))
     c = Curl()
     c.fetch(url, path)