linux删除指定日期前的日志文件中的记录

#!/bin/bash
#This script can only to a year of log records do operation
#时间格式必须为月+日(例如：Oct 20)
rm -r /logtime2 /logtime
touch /logtime2 /logtime /month

LogFile=/messages
month_path=/month
times=3days
############建立月份对照表##############
echo -e "1 Jan January\n2 Feb February\n3 Mar March\n4 Apr April\n5 May May\n6 June June\n7 July July\n8 Aug August\n9 Sept September\n10 Oct October\n11 Nov November\n12 Dec December">$month_path
########时间获取#################
cat $LogFile |awk '{print $1" "$2}'>logtime
Sys30daybeforeTimeMonth=$(LANG=C date -d '-$times'|awk '{print $2}') #月份
Sys30daybeforeTimeDay=$(LANG=C date -d '-$times'|awk '{print $3}') #日期
IntMonth=$(grep $Sys30daybeforeTimeMonth $month_path|awk '{print $1}')
Sys30DaysTime=$(echo "$IntMonth $Sys30daybeforeTimeDay")
#############判断##############################
NewTime=`cat /logtime |sed -e 's/ /-/g'`
for TimeDay in $NewTime;do
TimeMonth=`echo $TimeDay|awk -F'-' '{print $1}'`
NewTimeMonth=`grep $TimeMonth $month_path |awk '{print $1}'`
NewTimeDay=`echo $TimeDay|awk -F'-' '{print $2}'`
echo "$NewTimeMonth $NewTimeDay">>logtime2
done
Times=`cat /logtime2 |sed -e 's/ /-/g'`
for time1 in $Times
do
newtimemonth=$(echo $time1|awk -F'-' '{print $1}')
newtimeday=$(echo $time1|awk -F'-' '{print $2}')
newsystimemonth=$(echo $Sys30DaysTime|awk '{print $1}')
newsystimeday=$(echo $Sys30DaysTime|awk '{print $2}')
if [ $newtimemonth,$newtimeday ];then
if [ $newtimemonth -lt $newsystimemonth ];then
newtime1=`grep $newtimemonth $month_path |awk '{print $2}'`
time2=$(echo "$newtime1\ $newtimeday")
sed -in "/$time2/d" $LogFile
elif [ $newtimemonth -eq $newsystimemonth ] && [[ $newtimeday -lt $newsystimeday ]];then
newtime2=`grep $newtimemonth $month_path |awk '{print $2}'`
time3=`echo "$newtime2\ $newtimeday"`
sed -in "/$time3/d" $LogFile

fi
fi
done