备份tomcat日志，并且删除30天之前的备份：
mkdir -p /usr/local/tomcat/logs/cron
more /root/tomcat_cut_log.sh
#! /bin/bash
logs_path=/usr/local/tomcat/logs
d=`date +%Y-%m-%d`
d30=`date -d'30 day ago' +%Y-%m-%d`
cd ${log_path} && cp catalina.out $logs_path/cron/catalina.out.$d.log
echo > catalina.out
rm -rf $logs_path/cron/catalina.out.${d30}.log
chmod 755 /root/tomcat_cut_log.sh
crontab -e
00 00 * * * /bin/bash /root/tomcat_cut_log.sh