grep for a pattern "variable=value" and returning only matching entries having a value &gt-CodePudding

I am searching a kubernetes pod logs for the pattern “variable=value” ( e.g., variable=10 or variable=500) using the command below:

Kubectl logs -f | grep “variable=”

My question is that wether it is possible to modify the command above in order to return the logs where the variable value is greater than some threshold, e.g, for threshold=300, variable=301, variable=302 would be filetered in, but variable=299 would be filtered out

I know I can develop a small program for this, but rather I want a rapid solution in the command line direcly without the hassle of writing a small prgram.

CodePudding user response：

As a test, I've created this file:

Prompt> cat test.txt
var=2
var=22
var=222
blabla

First, I filter our the variable assignment lines:

Prompt> grep "var=" test.txt
var=2
var=22
var=222

Then, I filter on the condition of the values, in two ways:

Prompt> grep "var=" test.txt | awk -F '=' '{if ($2 > 25) print $1 "=" $2}'
var=222

Prompt> grep "var=" test.txt | awk -F '=' '{if ($2 < 25) print $1 "=" $2}'
var=2
var=22

CodePudding user response：

Here's a flexible solution that allows you specify parameters you like, and functions the same :

< test_filter_threshold.txt | 

mawk 'NF*=(____=="<")!=((___~"."? ___:___\
          )<= $(NF*=(!_<NF)*(__==$!_)))'  FS== OFS== \
                                          __="var" ___="1" ____=">="

var=2
var=22
var=222

___=4    ____='<'
var=2

___=200  ____='<'
var=2
var=22

___=200  ____='>='
var=222

___=200  ____=           # "<" is strictly less than, 
                         # all else def. to ">="
var=222

___='3.14159' ____='>='  # float point thresholds (TRHD) are valid 
var=22
var=222

___=   ____=             # missing TRHD def. to all
var=2
var=22
var=222

___='abc' ____='>='     # invalid TRHD def. to non-zero positive 
var=2
var=222
      1 var=2
      2 var=-22
      3 var=222
      4 blabla