how to capture details from nc

Question

by the following command we can identify which ip are using port 2181 and the relevant port

echo stat | nc localhost  2181
Zookeeper version: 3.4.6-91--1, built on 01/04/2018 10:34 GMT
Clients:
 /182.33.12.56:51397[1](queued=0,recved=43168,sent=43168)
 /182.33.12.36:51915[1](queued=0,recved=1305948,sent=1305948)
 /182.33.12.60:43528[1](queued=0,recved=793,sent=793)
 /182.33.12.60:40151[1](queued=0,recved=5990,sent=5990)
 /182.33.12.35:52973[1](queued=0,recved=117840,sent=117840)
 /182.33.12.56:53533[1](queued=0,recved=76252,sent=76489)


Latency min/avg/max: 0/0/329
Received: 6097607
Sent: 6324062
Connections: 14
Outstanding: 0
Zxid: 0x50027d362
Mode: follower
Node count: 90630

what I want is to capture only the ip's with there ports

so the expected output should be

 182.33.12.56:51397
 182.33.12.36:51915
 182.33.12.60:43528
 182.33.12.60:40151
 182.33.12.35:52973
 182.33.12.56:53533

so we try this

echo stat | nc localhost  2181 | grep -E  "([0-9]{1,3}[\.]){3}[0-9]{1,3}" | awk '{print $1}'
/182.33.12.56:51397[1](queued=0,recved=43282,sent=43282)
/182.33.12.36:51915[1](queued=0,recved=1305988,sent=1305988)
/182.33.12.60:43528[1](queued=0,recved=815,sent=815)
/182.33.12.35:53110[0](queued=0,recved=1,sent=0)
/182.33.12.60:40151[1](queued=0,recved=6013,sent=6013)
/182.33.12.35:52973[1](queued=0,recved=117857,sent=117857)

but without success

Answer 1

Try it with the -o option to grep:

echo stat | nc localhost  2181 | grep -oP  "([0-9]{1,3}\.){3}[0-9]{1,3}:\d+" 

This should print only the part of the line matching the regex, instead of the entire line. And it also obviates the need for an additional ‘awk’ invocation.