检查elk程序运行状态，并在没有运行时启动的shell脚本

#!/bin/bash

CheckProcess()
{
  if [ "$1" = "" ];
  then
    return 1
  fi

  PROCESS_NUM=`ps -ef | grep "$1" | grep -v "grep" | wc -l`
  if [ $PROCESS_NUM -eq 1 ];
  then
    return 0
  else
    return 1
  fi
}

CheckPort()
{
  if [ "$1" = "" ];
  then
    return 1
  fi

  PROCESS_NUM=`netstat -an | grep "$1" | wc -l`
  if [ $PROCESS_NUM -eq 1 ];
  then
    return 0
  else
    return 1
  fi
}

while [ 1 ]; do
  CheckProcess "elasticsearch"
  Check_ELA_RET=$?
  CheckProcess "logstash"
  Check_LOG_RET=$?
  CheckPort 5601
  Check_KIB_RET=$?
  if [ $Check_ELA_RET -eq 1 ];
  then
    /home/elk/elasticsearch-6.2.4/bin/elasticsearch -d
  elif [ $Check_LOG_RET -eq 1 ];
  then
    /home/elk/logstash-6.2.4/bin/logstash -f /home/elk/logstash-6.2.4/config/logstash.conf &
  elif [ $Check_KIB_RET -eq 1 ];
  then