awk - 提取包含某个关键字的段落

前提

awk是一种处理文本文件的语言，是一个强大的文本分析工具。
本文将使用命令awk将具有某个关键字的段落提取出来。

准备数据

"finalizer" #3 daemon prio=8 os_prio=0 tid=0x00007fb2dc1aa800 nid=0x63f6 in object.wait() [0x00007fb2be61f000]
   java.lang.thread.state: waiting (on object monitor)
    at java.lang.object.wait(native method)
    - waiting on <0x00000000d6708ed8> (a java.lang.ref.referencequeue$lock)
    at java.lang.ref.referencequeue.remove(referencequeue.java:144)
    - locked <0x00000000d6708ed8> (a java.lang.ref.referencequeue$lock)
    at java.lang.ref.referencequeue.remove(referencequeue.java:165)
    at java.lang.ref.finalizer$finalizerthread.run(finalizer.java:216)

"reference handler" #2 daemon prio=10 os_prio=0 tid=0x00007fb2dc1a6000 nid=0x63f5 in object.wait() [0x00007fb2be720000]
   java.lang.thread.state: waiting (on object monitor)
    at java.lang.object.wait(native method)
    - waiting on <0x00000000d6706c00> (a java.lang.ref.reference$lock)
    at java.lang.object.wait(object.java:502)
    at java.lang.ref.reference.tryhandlepending(reference.java:191)
    - locked <0x00000000d6706c00> (a java.lang.ref.reference$lock)
    at java.lang.ref.reference$referencehandler.run(reference.java:153)

"main" #1 prio=5 os_prio=0 tid=0x00007fb2dc04b800 nid=0x63ef waiting on condition [0x00007fb2e3382000]
   java.lang.thread.state: timed_waiting (sleeping)
    at java.lang.thread.sleep(native method)
    at com.test.test.main(test.java:16)
    at sun.reflect.nativemethodaccessorimpl.invoke0(native method)
    at sun.reflect.nativemethodaccessorimpl.invoke(nativemethodaccessorimpl.java:62)
    at sun.reflect.delegatingmethodaccessorimpl.invoke(delegatingmethodaccessorimpl.java:43)
    at java.lang.reflect.method.invoke(method.java:498)
    at org.springframework.boot.loader.mainmethodrunner.run(mainmethodrunner.java:48)
    at org.springframework.boot.loader.launcher.launch(launcher.java:87)
    at org.springframework.boot.loader.launcher.launch(launcher.java:50)
    at org.springframework.boot.loader.jarlauncher.main(jarlauncher.java:51)

段落提取

假设我们需要的关键字为 nid=0x63ef

keywords=0x63ef
## 以前后双换行符为一个段落
## 查询包含关键字nid=0x63ef的段落
awk 'begin {rs = "\n\n+";ors = "\n\n"} /'${keywords}'/ {print $0}' test.log
## 查询不包含关键字nid=0x63ef的段落
awk 'begin {rs = "\n\n+";ors = "\n\n"} !/'${keywords}'/ {print $0}' test.log