下面示例是启动名字叫modbus_master 的进程，先查找有没有启动，没有启动则进入相应目录启动
'''

!/bin/sh

modbus_pid=ps -ef | grep modbus_master | grep -v grep | awk '{print $1}'

if [ -z "$modbus_pid" ];

then

echo "[ not find modbus_master pid ]"
cd /usr/bin
modbus_master&
echo "[modbus_master start]"

else

echo "find result: $modbus_pid "

fi
'''