shell 获取关键字后几位字符

怼烎@ 2022-10-24 01:48 184阅读 0赞

文件: test.txt

"http-nio-8888-exec-3" #30 daemon prio=5 os_prio=0 tid=0x00007f9c10f39800 nid=0x687a waiting on condition [0x00007f9bde0ed000]
       java.lang.Thread.State: WAITING (parking)
    	at sun.misc.Unsafe.park(Native Method)
    	- parking to wait for  <0x00000000eca402c0> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
    	at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
    	at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
    	at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
    	at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:108)
    	at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:33)
    	at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
    	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
    	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    	at java.lang.Thread.run(Thread.java:748)
    
       Locked ownable synchronizers:
    	- None

比如我想获取关键字 concurrent 及后面 6 个字符，那么可以用以下命令:

# 这里的 16 是: concurrent 占用 10 个字符，外加后面的 6 个字符
    cat test.txt | awk '{ if(match($0,"concurrent")) { print substr($0,RSTART,16) }}'

获取效果如下:

root@dreamboy:~/test# cat test.txt | awk '{ if(match($0,"concurrent")) { print substr($0,RSTART,16) }}'
    concurrent.locks
    concurrent.locks
    concurrent.locks
    concurrent.Linke
    concurrent.Threa
    concurrent.Threa
    concurrent.Threa
    root@dreamboy:~/test#

如果不想要 concurrent 关键字，可以使用:

cat test.txt | awk '{ if(match($0,"concurrent")) { print substr($0,RSTART+RLENGTH,6) }}'

# 补充资料 - awk 内置变量 #

<table> 
 <thead> 
  <tr> 
   <th>属 性</th> 
   <th>说 明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>$0</td> 
   <td>当前记录行，代表一行记录</td> 
  </tr> 
  <tr> 
   <td><span><span><span> 1 &nbsp; 1~ </span><span><span><span style="height: 0.64444em; vertical-align: 0em;"></span><span>1</span><span>&nbsp;</span></span></span></span></span>n</td> 
   <td>当前记录的第n个字段，字段间由FS分隔</td> 
  </tr> 
  <tr> 
   <td>FS</td> 
   <td>输入字段分隔符，默认是空格</td> 
  </tr> 
  <tr> 
   <td>NF</td> 
   <td>当前记录中的字段个数，就是有多少列，一般取最后一列字段</td> 
  </tr> 
  <tr> 
   <td>NR</td> 
   <td>已经读出的记录数，就是行号，从1开始</td> 
  </tr> 
  <tr> 
   <td>RS</td> 
   <td>输入的记录分隔符，默认为换行符</td> 
  </tr> 
  <tr> 
   <td>OFS</td> 
   <td>输出字段分隔符，默是空格</td> 
  </tr> 
  <tr> 
   <td>ORS</td> 
   <td>输出的记录分隔符，默认为换行符</td> 
  </tr> 
  <tr> 
   <td>ARGC</td> 
   <td>命令行参数个数</td> 
  </tr> 
  <tr> 
   <td>ARGV</td> 
   <td>命令行参数数组</td> 
  </tr> 
  <tr> 
   <td>FILENAME</td> 
   <td>当前输入文件的名字</td> 
  </tr> 
  <tr> 
   <td>IGNORECASE</td> 
   <td>如果为真，则进行忽略大小写的匹配</td> 
  </tr> 
  <tr> 
   <td>ARGIND</td> 
   <td>当前被处理文件的ARGV标志符</td> 
  </tr> 
  <tr> 
   <td>CONVFMT</td> 
   <td>数字转换格式 %.6g</td> 
  </tr> 
  <tr> 
   <td>ENVIRON</td> 
   <td>UNIX环境变量</td> 
  </tr> 
  <tr> 
   <td>ERRNO</td> 
   <td>UNIX系统错误消息</td> 
  </tr> 
  <tr> 
   <td>FIELDWIDTHS</td> 
   <td>输入字段宽度的空白分隔字符串</td> 
  </tr> 
  <tr> 
   <td>FNR</td> 
   <td>当前记录数</td> 
  </tr> 
  <tr> 
   <td>OFMT</td> 
   <td>数字的输出格式 %.6g</td> 
  </tr> 
  <tr> 
   <td>RSTART</td> 
   <td>被匹配函数匹配的字符串首</td> 
  </tr> 
  <tr> 
   <td>RLENGTH</td> 
   <td>被匹配函数匹配的字符串长度</td> 
  </tr> 
  <tr> 
   <td>SUBSEP</td> 
   <td>\034</td> 
  </tr> 
 </tbody> 
</table>