shell 日期减法 自加

#!/bin/bash



logname=/home/test.log



filename=/opt/test.txt

count=0



while true; do

    LASTLINE=`date +"%Y-%m-%d %H:%M:%S"`

    ls $filename 

    CURTIME=`date +"%Y-%m-%d %H:%M:%S"`

    Sys_data=`date -d "$CURTIME" +%s`

    In_data=`date -d "$LASTLINE" +%s`

    interval=`expr $Sys_data - $In_data`

    ((count +=1))

    if (( $interval > 1 || $count==10 ))

        then

        count=0

        echo "ls $filename  cost time: $interval" >> $logname

        date >> $logname

    fi

    sleep 2

done