Plenty of options already out there
eg Using ADRCI
See this link for a nice example
https://coskan.wordpress.com/2010/12/06/alert-log-monitoring-script-via-adrci/ Also, if you want, you can have the full power of SQL to access the alert log, eg
SQL> desc V$diag_alert_ext
Name Null? Type
----------------------------------------- -------- ----------------------------
ADDR RAW(8)
INDX NUMBER
INST_ID NUMBER
CON_ID NUMBER
ADR_PATH_IDX VARCHAR2(445)
ADR_HOME VARCHAR2(445)
ORIGINATING_TIMESTAMP TIMESTAMP(9) WITH TIME ZONE
NORMALIZED_TIMESTAMP TIMESTAMP(9) WITH TIME ZONE
ORGANIZATION_ID VARCHAR2(67)
COMPONENT_ID VARCHAR2(67)
HOST_ID VARCHAR2(67)
HOST_ADDRESS VARCHAR2(49)
MESSAGE_TYPE NUMBER
MESSAGE_LEVEL NUMBER
MESSAGE_ID VARCHAR2(67)
MESSAGE_GROUP VARCHAR2(67)
CLIENT_ID VARCHAR2(67)
MODULE_ID VARCHAR2(67)
PROCESS_ID VARCHAR2(35)
THREAD_ID VARCHAR2(67)
USER_ID VARCHAR2(131)
INSTANCE_ID VARCHAR2(67)
DETAILED_LOCATION VARCHAR2(163)
UPSTREAM_COMP_ID VARCHAR2(103)
DOWNSTREAM_COMP_ID VARCHAR2(103)
EXECUTION_CONTEXT_ID VARCHAR2(103)
EXECUTION_CONTEXT_SEQUENCE NUMBER
ERROR_INSTANCE_ID NUMBER
ERROR_INSTANCE_SEQUENCE NUMBER
MESSAGE_TEXT VARCHAR2(2051)
MESSAGE_ARGUMENTS VARCHAR2(515)
SUPPLEMENTAL_ATTRIBUTES VARCHAR2(515)
SUPPLEMENTAL_DETAILS VARCHAR2(515)
PARTITION NUMBER
RECORD_ID NUMBER
FILENAME VARCHAR2(515)
LOG_NAME VARCHAR2(67)
PROBLEM_KEY VARCHAR2(553)
VERSION NUMBER
CON_UID NUMBER
CONTAINER_ID NUMBER
CONTAINER_NAME VARCHAR2(33)
SQL> select originating_timestamp, message_text
2 from V$diag_alert_ext
3 where originating_timestamp > cast(sysdate-3/24 as timestamp);
ORIGINATING_TIMESTAMP
---------------------------------------------------------------------------
MESSAGE_TEXT
---------------------------------------------------------------------------
04-AUG-17 12.00.04.965000000 PM +08:00
Thread 1 advanced to log sequence 527 (LGWR switch)
04-AUG-17 12.00.04.971000000 PM +08:00
Current log# 2 seq# 527 mem# 0: C:\ORACLE\ORADATA\DB122\REDO02.LOG
04-AUG-17 12.00.05.350000000 PM +08:00
Archived Log entry 526 added for T-1.S-526 ID 0x33fe90fc LAD:1
but this depends on your version of Oracle