added rpms_not_installed.sh

rpms_not_installed.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+#  vim:ts=4:sts=4:sw=4:et
+#
+#  Author: Hari Sekhon
+#  Date: 2020-08-23 23:53:52 +0100 (Sun, 23 Aug 2020)
+#
+#  https://github.com/harisekhon/bash-tools
+#
+#  License: see accompanying Hari Sekhon LICENSE file
+#
+#  If you're using my code you're welcome to connect with me on LinkedIn and optionally send me feedback to help steer this or other code I publish
+#
+#  https://www.linkedin.com/in/harisekhon
+#
+
+set -euo pipefail
+[ -n "${DEBUG:-}" ] && set -x
+srcdir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+# shellcheck disable=SC1090
+. "$srcdir/lib/utils.sh"
+
+# shellcheck disable=SC1090
+. "$srcdir/lib/packages.sh"
+
+# shellcheck disable=SC2034,SC2154
+usage_description="
+Checks a given list of RPM packages and returns those already installed
+
+$package_args_description
+
+Tested on CentOS
+"
+
+# used by usage() in lib/utils.sh
+# shellcheck disable=SC2034
+usage_args="<packages>"
+
+help_usage "$@"
+
+process_package_args "$@" |
+grep -vFx -f <(installed_rpms)