As a DBA, one of the primary responsibility is morning the alert log and identifying the issues and fixing them. Some times we may need no of ORA errors and each error count. Using below mentioned command we can get the required output easily. Hope this helps someone.
/home/oracle$ grep -oh "\w*ORA-\w*" alert_ORCL.log |sort|uniq -c
1 ORA-00028
132 ORA-00060
5 ORA-00202
4 ORA-00206
1 ORA-00221
5 ORA-00235
5 ORA-00245
3 ORA-00272
/home/oracle$
/home/oracle$ grep -oh "\w*ORA-\w*" alert_ORCL.log |sort|uniq -c
1 ORA-00028
132 ORA-00060
5 ORA-00202
4 ORA-00206
1 ORA-00221
5 ORA-00235
5 ORA-00245
3 ORA-00272
/home/oracle$