New package: IDL (#17451)

* New package: IDL

* Update var/spack/repos/builtin/packages/idl/package.py

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>

* Update var/spack/repos/builtin/packages/idl/package.py

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>

* added license header and changed url_for_version to just url

* removed unused imports, addressed comments

* removed trailing whitespace on line 14

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>

var/spack/repos/builtin/packages/idl/package.py

+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+import os
+
+
+class Idl(Package):
+    """IDL Software: Interactive Data Visulation.
+
+    Note: IDL is a licensed software. You will also need an existing
+    downloaded tarball of IDL in your current directory or in a
+    spack mirror in order to install."""
+
+    homepage = "https://www.harrisgeospatial.com/Software-Technology/IDL"
+    manual_download = True
+    url = "file://{0}/idl8.7-linux.tar.gz".format(os.getcwd())
+
+    maintainers = ['francinelapid']
+
+    license_required = True
+
+    def install(self, spec, prefix):
+
+        # replace default install dir to self.prefix by editing answer file
+        filter_file('/usr/local/harris', prefix, 'silent/idl_answer_file')
+
+        # execute install script
+        install_script = Executable('./install.sh')
+        install_script('-s', input='silent/idl_answer_file')
+
+    def setup_run_environment(self, env):
+
+        # set necessary environment variables
+        env.prepend_path('EXELIS_DIR', self.prefix)
+        env.prepend_path('IDL_DIR', self.prefix.idl)
+
+        # add bin to path
+        env.prepend_path('PATH', self.prefix.idl.bin)