old_contents: ##############################################################################
  # Copyright (c) 2013, Lawrence Livermore National Security, LLC.
  # Produced at the Lawrence Livermore National Laboratory.
  #
  # This file is part of Spack.
  # Written by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
  # LLNL-CODE-647188
  #
  # For details, see https://scalability-llnl.github.io/spack
  # Please also see the LICENSE file for our notice and the LGPL.
  #
  # This program is free software; you can redistribute it and/or modify
  # it under the terms of the GNU General Public License (as published by
  # the Free Software Foundation) version 2.1 dated February 1999.
  #
  # This program is distributed in the hope that it will be useful, but
  # WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
  # conditions of the GNU General Public License for more details.
  #
  # You should have received a copy of the GNU Lesser General Public License
  # along with this program; if not, write to the Free Software Foundation,
  # Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ##############################################################################
  from itertools import product
  from spack.util.executable import which
  
  # Supported archvie extensions.
  PRE_EXTS = ["tar"]
  EXTS     = ["gz", "bz2", "xz", "Z", "zip", "tgz"]
  
  # Add EXTS last so that .tar.gz is matched *before* tar.gz
  ALLOWED_ARCHIVE_TYPES = [".".join(l) for l in product(PRE_EXTS, EXTS)] + EXTS
  
  
  def allowed_archive(path):
      return any(path.endswith(t) for t in ALLOWED_ARCHIVE_TYPES)
  
  
  def decompressor_for(path):
      """Get the appropriate decompressor for a path."""
      tar = which('tar', required=True)
      tar.add_default_arg('-xf')
      return tar
  
new_contents: ##############################################################################
  # Copyright (c) 2013, Lawrence Livermore National Security, LLC.
  # Produced at the Lawrence Livermore National Laboratory.
  #
  # This file is part of Spack.
  # Written by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
  # LLNL-CODE-647188
  #
  # For details, see https://scalability-llnl.github.io/spack
  # Please also see the LICENSE file for our notice and the LGPL.
  #
  # This program is free software; you can redistribute it and/or modify
  # it under the terms of the GNU General Public License (as published by
  # the Free Software Foundation) version 2.1 dated February 1999.
  #
  # This program is distributed in the hope that it will be useful, but
  # WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
  # conditions of the GNU General Public License for more details.
  #
  # You should have received a copy of the GNU Lesser General Public License
  # along with this program; if not, write to the Free Software Foundation,
  # Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ##############################################################################
  from itertools import product
  from spack.util.executable import which
  
  # Supported archvie extensions.
  PRE_EXTS = ["tar"]
  EXTS     = ["gz", "bz2", "xz", "Z", "zip", "tgz"]
  
  # Add EXTS last so that .tar.gz is matched *before* tar.gz
  ALLOWED_ARCHIVE_TYPES = [".".join(l) for l in product(PRE_EXTS, EXTS)] + EXTS
  
  
  def allowed_archive(path):
      return any(path.endswith(t) for t in ALLOWED_ARCHIVE_TYPES)
  
  
  def decompressor_for(path):
      """Get the appropriate decompressor for a path."""
      if path.endswith(".zip"):
          unzip = which('unzip', required=True)
          return unzip
      tar = which('tar', required=True)
      tar.add_default_arg('-xf')
      return tar
  
subject: Use unzip to unpackage .zip files