Filter column with awk and regexp

Question

I\'ve a pretty simple question. I\'ve a file containing several columns and I want to filter them using awk.

So the column of interest is the 6th column and I want to fi

Answer 1

Try this:

awk '$6 ~/^([1-9]|0[1-9]|[1-9][0-9]|100)+[S|M]+([1-9]|0[1-9]|[1-9][0-9]|100)+[S|M]$/' file.txt

Because you did not say exactly how the formatting will be in column 6, the above will work where the column looks like '03M05S', '40S100M', or '3M5S'; and exclude all else. For instance, it will not find '03F05S', '200M05S', '03M005S, 003M05S, or '003M005S'.

If you can keep the digits in column 6 to two when 0-99, or three when exactly 100 - meaning exactly one leading zero when under 10, and no leading zeros otherwise, then it is a simpler match. You can use the above pattern but exclude single digits (remove the first [1-9] condition), e.g.

awk '$6 ~/^(0[1-9]|[1-9][0-9]|100)+[S|M]+(0[1-9]|[1-9][0-9]|100)+[S|M]$/' file.txt