vi /root/db_clearlog.sh
chmod 700 /root/db_clearlog.sh
55 6 * * * /bin/sh db_clearlog.sh

cat db_clearlog.sh
##############################################################################################

#!/bin/bash
######################################
#warning!!!!!!!!!!!!!
#please adjust values below:
#cluster_name,inst_name
######################################
cluster_name=db
inst_name=db1
db_aud_path=/u01/app/oracle/admin/${cluster_name}/adump
db_diag_path=/u01/app/oracle/diag/rdbms/${cluster_name}/${inst_name}/trace/

######################################
#aud log clear
######################################

cd /tmp/;
find ${db_aud_path} -mtime +15 -print|xargs rm -rf "*.aud";
find /u01/app/12.2.0/grid/rdbms/audit/ -mtime +15 -print|xargs rm -rf "*.aud";

######################################
#diag log clear
######################################

cd /tmp/;
find ${db_diag_path} -mtime +15 -print|xargs rm -rf "*.trm";
find ${db_diag_path} -mtime +15 -print|xargs rm -rf "*.trc";
find /u01/app/grid/diag/crs/`hostname`/crs/trace -mtime +15 -print|xargs rm -rf "*.trc";
find /u01/app/grid/diag/crs/`hostname`/crs/trace -mtime +15 -print|xargs rm -rf "*.trm";

######################################
#listen log clear
######################################
cd /tmp/;
find /u01/app/grid/diag/tnslsnr/`hostname`/listener_scan1/alert -mtime +30 -print|xargs rm -rf "*.xml";
find /u01/app/grid/diag/tnslsnr/`hostname`/asmnet1lsnr_asm/alert -mtime +30 -print|xargs rm -rf "*.xml";
find /u01/app/grid/diag/tnslsnr/`hostname`/listener/alert -mtime +30 -print|xargs rm -rf "*.xml";