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

I would do the regex check and the numeric validation as different steps. This code works with GNU awk:

$ cat data
a b c d e 132x123y
a b c d e 123S12M
a b c d e 12S23M
a b c d e 12S23Mx

We'd expect only the 3rd line to pass validation

$ gawk '
    match($6, /^([[:digit:]]{1,3})[SM]([[:digit:]]{1,3})[SM]$/, m) && 
    1 <= m[1] && m[1] <= 100 && 
    1 <= m[2] && m[2] <= 100 {
        print
    }
' data
a b c d e 12S23M

For maintainability, you could encapsulate that into a function:

gawk '
    function validate6() {
        return( match($6, /^([[:digit:]]{1,3})[SM]([[:digit:]]{1,3})[SM]$/, m) && 
                1<=m[1] && m[1]<=100 && 
                1<=m[2] && m[2]<=100 );
    }
    validate6() {print}
' data