Extract substring from a field with single awk in AIX

Question

I have a file file with content like:

stringa    8.0.1.2     stringx
stringb    12.01.0.0    stringx

I have to get a substring from field 2 (first two values with the dot).
I am currently doing cat file | awk '{print $2}' | awk -F. '{print $1"."$2}' and getting the expected output:

8.0
12.01

The query is how to do this with single awk?
I have tried with match() but not seeing an option for a back reference. Any help would be appreciated.

Answer 1

You can do something like this.

$ awk '{ split($2,str,"."); print str[1]"."str[2] }' file
8.0
12.01

Also, keep in mind that your cat is not needed. Simply give the file directly to awk.

Answer 2

With GNU grep please try following command once.

grep -oP '^\S+\s+\K[[:digit:]]+\.[[:digit:]]+' Input_file

Explanation: Using GNU grep here. Using its -oP options to print matched part and enable PCRE with -P option here. In main program, matching from starting non-space characters followed by 1 or more spaces, then using \K option to forget that match. Then matching 1 or more digits occurrences followed by a dot; which is further followed by digits. If a match is found then it prints matched value.