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regexawkgnuplot

Regular expression using awk for forcing data into gnuplot format

I'm relay struggling to get from this: 

Wed Sep 24 09:18:01 BST 2014 -- temp=51.9'C -- message from script /usr/src/scripts/wifi_test_2.sh

To this for input into gnuplot format: 

09:18:01 51.9

Using regular expression and awk

1) I can recognize the "temp=" using /temp=/ but how can I print out 4 characters after the = sign?

Solution

  • Using GNU awk for gensub():

    $ awk '{print $4, gensub(/.*temp=([0-9.]+).*/,"\\1","")}' file
09:18:01 51.9

    With other awks use match() and substr():

    $ awk '{print $4, substr($0,match($0,/temp=[0-9.]+/)+5,RLENGTH-5)}' file
09:18:01 51.9

    With sed:

    $ sed -r 's/.*(..:..:..).*temp=([0-9.]+).*/\1 \2/' file
09:18:01 51.9