#!/usr/bin/env bash

# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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PBS_NODES_PATH=`which pbsnodes 2>/dev/null`
if [ -z $PBS_NODES_PATH ]
then
  echo Could not find pbsnodes in path. Cannot check available number of nodes. >&2
  exit 1
fi
if [ -z $1 ]
then
  echo Usage: checknodes queue-name >&2
  exit 2
fi
# the number of nodes marked 'free', and which do not contain a jobs attribute from the server or from the moms.
$PBS_NODES_PATH :$1 | awk 'BEGIN {c=0} /state = free/ {getline;getline;getline;getline; if ($0 !~ /jobs =/ && $0 !~ /jobs=[0-9].*/)  c++ ; } END {print c}'