linux shell实现守护进程脚本

#! /bin/sh
#进程名字可修改
PRO_NAME=udhcpc
WLAN=ra0
 
while true ; do
 
#    用ps获取$PRO_NAME进程数量
  NUM=`ps aux | grep ${PRO_NAME} | grep -v grep |wc -l`
#  echo $NUM
#    少于1，重启进程
  if [ "${NUM}" -lt "1" ];then
    echo "${PRO_NAME} was killed"
    ${PRO_NAME} -i ${WLAN}
#    大于1，杀掉所有进程，重启
  elif [ "${NUM}" -gt "1" ];then
    echo "more than 1 ${PRO_NAME},killall ${PRO_NAME}"
    killall -9 $PRO_NAME
    ${PRO_NAME} -i ${WLAN}
  fi
#    kill僵尸进程
  NUM_STAT=`ps aux | grep ${PRO_NAME} | grep T | grep -v grep | wc -l`
 
  if [ "${NUM_STAT}" -gt "0" ];then
    killall -9 ${PRO_NAME}
    ${PRO_NAME} -i ${WLAN}
  fi
done
 
exit 0