最近在学习python，随手写了一个实时监控alert日志的小程序：
import time
ol = []
nl = []
lweek = ['Mon','Tue','Wed','Thu','Fri','Sat','Sun']
fname = '/home/db/oracle/admin/sms/bdump/alert_sms1.log'
while True:
        ol = nl[:]
        nl = []
        v = ''
        k = ''
        l = []
        f = open(fname)
        for line in f:
                tl = line.split()
#判断是否是时间戳，如果是，将前一个时间戳和当前时间戳之间的有警告信息的内容放到nl中
                if ( tl[0] in lweek and int(tl[2]) in range(1,32) and tl[4] == 'CST'):
#根据告警关键词过滤，可以自己根据需要添加
                        if "ORA-" in v or "Errors" in v or "Deadlock" in v:
                                s = k + "|" + v
                                nl.append(s)
                        v = ''
                        k = line
#如果不是时间戳，将内容叠加到变量v中
                else:
                        v = v + '|' + line
        f.close()
        if "ORA-" in v or "Errors" in v or "Deadlock" in v:
                s = k + "|" + v
                nl.append(s)
#取前后两次告警信息的差集并输出
        l = list(set(nl).difference(set(ol)))
        if l is not None:
                for x in l:
                       print x
        time.sleep(10)


测试：
oracle@bjmbsdb01[/home/db/oracle/admin/sms/bdump]python mon_alert.py
Tue Mar 17 14:15:28 CST 2015
||ORA-1119 signalled during: alter tablespace users add datafile 'a'...

Tue Mar 17 14:16:21 CST 2015
||ORA-1119 signalled during: alter tablespace users add datafile 'a'...

Tue Mar 17 14:15:53 CST 2015
||Global Enqueue Services Deadlock detected. More info in file
| /home/db/oracle/admin/sms/bdump/sms1_lmd0_6620.trc.

Tue Mar 17 14:20:00 CST 2015
||alter tablespace users add datafile 'a'
|ORA-1119 signalled during: alter tablespace users add datafile 'a'...