实时扫描文件并在遇到5行连续相同的行时执行某些命令

Question

Mysql日志有如下内容：

1649560 Query select * from actions where uniqueid like 'ernie-1328697839.1233158-%-dequeue' and class='queue' and server='ernie' and time<='1328698322' and action='dequeue' limit 1
1649560 Query select * from actions where uniqueid like 'ernie-1328697839.1233158-%-dequeue' and class='queue' and server='ernie' and time<='1328698322' and action='dequeue' limit 1
1649560 Query select * from actions where uniqueid like 'ernie-1328697839.1233158-%-dequeue' and class='queue' and server='ernie' and time<='1328698322' and action='dequeue' limit 1
1649560 Query select * from actions where uniqueid like 'ernie-1328697839.1233158-%-dequeue' and class='queue' and server='ernie' and time<='1328698322' and action='dequeue' limit 1
1649560 Query select * from actions where uniqueid like 'ernie-1328697839.1233158-%-dequeue' and class='queue' and server='ernie' and time<='1328698322' and action='dequeue' limit 1
1649560 Query select * from actions where uniqueid like 'ernie-1328697839.1233158-%-dequeue' and class='queue' and server='ernie' and time<='1328698322' and action='dequeue' limit 1
1649560 Query select * from actions where uniqueid like 'ernie-1328697839.1233158-%-dequeue' and class='queue' and server='ernie' and time<='1328698322' and action='dequeue' limit 1
1649560 Query select * from actions where uniqueid like 'ernie-1328697839.1233158-%-dequeue' and class='queue' and server='ernie' and time<='1328698322' and action='dequeue' limit 1

我想要一个bash脚本，它将执行如下操作：

脚本将实时扫描tail -F mysql.log)

• If文件(类似于echo "yes")

，它遇到5行连续相同的行)，然后调用一些命令(比如echo "yes"))

Answer 1

 awk '$0 != l { l=$0; c=0 }
      l=$0 {c++; if (c>=5) {system("YOURCOMMAND HERE")}}' LOGFILE

能为你做这件事。但你所说的实时是什么意思？如果必须不断地运行，请为其设置一些fifo机制，或者类似的机制。或者简单地做：

 tail -F LOGFILE | <THEABOVE_AWK_SCRIPT>