如何提取一行后行范围

Question

我正在尝试提取一个包含domain:的行，然后是从nameservers"到]的一系列行。我知道如何分别使用grep和awk分别完成这些工作，但不知道如何一次完成。

输入数据：

domain: stackexchange.com date: Mon Jul 3 00:43:49 2017 output_dir:        /tmp/stackexchange.com.12653
INFO:root:crawl: exiting dom: 'stackexchange.com' took: 10s
INFO:root:2017-07-03 00:44:06:370 slave.py: exiting args.url: 'stackexchange.com' took: 3s
+ comparing web systems

  "mail_server_ip": [],              |   "mail_server_ip": []
  "nameservers": [
    "ns-925.awsdns-51.net.",
    "ns-1029.awsdns-00.org.",
    "ns-cloud-d1.googledomains.com.",
    "ns-cloud-d2.googledomains.com.",
  ],
  "nameservers_domains": [           |   "nameservers_domains": [], 
    "m

期望产出：

  domain: stackexchange.com date: Mon Jul 3 00:43:49 2017 output_dir:        
  "nameservers": [
    "ns-925.awsdns-51.net.",
    "ns-1029.awsdns-00.org.",
    "ns-cloud-d1.googledomains.com.",
    "ns-cloud-d2.googledomains.com.",
  ],

单独提取数据的命令：

  grep "domain:" test_sample.txt      
  awk '/nameservers"/,/]/' test_sample.txt

Answer 1

awk方法

awk '/^domain:/{print}/"nameservers":/,/]/' test_sample.txt

Answer 2

采用P (PCRE)选项的grep方法：

grep -Poz 'domain: .+ output_dir:|\s*"nameservers": \[[^][]+\],\n' test_sample.txt

产出：

domain: stackexchange.com date: Mon Jul 3 00:43:49 2017 output_dir:
  "nameservers": [
    "ns-925.awsdns-51.net.",
    "ns-1029.awsdns-00.org.",
    "ns-cloud-d1.googledomains.com.",
    "ns-cloud-d2.googledomains.com.",
  ],

主要的模式是基于regex交替组<domain_line>|<nameservers_lines>。