Как добавить верхние n строк из многострочной строки в bash (sed / awk / ??)

Question

Учитывая количество потоков потоков jstack, мне нужно выделить верхние x-строки из трассировки стека каждого потока.

Я могу экстрагировать каждую трассировку стека потоков, но как только у меня есть многострочная строка, как экстрагировать верхние строки x?

Например, для каждой из трасс трассировки ниже, выход должен быть

    at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
    at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
    at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)
    at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)

для первой трассы, если x = 4.

"kafka-producer-network-thread | producer-1" Id=279 RUNNABLE (in native)
    at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
    at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
    at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)
    at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
    at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
    at org.apache.kafka.common.network.Selector.select(Selector.java:686)
    at org.apache.kafka.common.network.Selector.poll(Selector.java:408)
    at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:460)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:239)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:163)
    at java.lang.Thread.run(Thread.java:748)

"kafka-producer-network-thread | producer-4" Id=660 RUNNABLE (in native)
    at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
    at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
    at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)
    at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
    at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
    at org.apache.kafka.common.network.Selector.select(Selector.java:686)
    at org.apache.kafka.common.network.Selector.poll(Selector.java:408)
    at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:460)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:239)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:163)
    at java.lang.Thread.run(Thread.java:748)

"kafcli-poller-18" Id=322 RUNNABLE (in native)
    at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
    at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
    at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)
    at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
    at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
    at org.apache.kafka.common.network.Selector.select(Selector.java:686)
    at org.apache.kafka.common.network.Selector.poll(Selector.java:408)
    at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:460)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:261)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:233)
    at org.apache.kafka.clients.consumer.KafkaConsumer.pollOnce(KafkaConsumer.java:1171)
    at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1115)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:748)

"kafka-producer-network-thread | producer-20" Id=1746 RUNNABLE (in native)
    at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
    at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
    at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)
    at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
    at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
    at org.apache.kafka.common.network.Selector.select(Selector.java:686)
    at org.apache.kafka.common.network.Selector.poll(Selector.java:408)
    at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:460)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:239)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:163)
    at java.lang.Thread.run(Thread.java:748)

"kafcli-poller-3" Id=287 RUNNABLE (in native)
    at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
    at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
    at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)
    at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
    at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
    at org.apache.kafka.common.network.Selector.select(Selector.java:686)
    at org.apache.kafka.common.network.Selector.poll(Selector.java:408)
    at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:460)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:261)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:233)
    at org.apache.kafka.clients.consumer.KafkaConsumer.pollOnce(KafkaConsumer.java:1171)
    at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1115)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:748)

"kafka-producer-network-thread | producer-12" Id=1200 RUNNABLE (in native)
    at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
    at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
    at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)
    at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
    at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
    at org.apache.kafka.common.network.Selector.select(Selector.java:686)
    at org.apache.kafka.common.network.Selector.poll(Selector.java:408)
    at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:460)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:239)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:163)
    at java.lang.Thread.run(Thread.java:748)

Answer 1

Попробуйте приведенный ниже фрагмент

awk '/in native/ {for(i=1; i<=4; i++) {getline; print}}' temp.log

temp.log В файле содержится образец журнала в вашем вопросе

Answer 2

С grep будет намного проще

grep -A4 RUNNABLE logfile