Count total number of lines of a string before/after a pattern match

January 16, 2023

I have a file that I need to count the number of lines of a particular string that appears [/done] before a certain pattern match TAG: and then to continue and keep on increasing in counting till the next pattern match and so and so on till the end of file.

My file

    done
    [/done]
    done
    [/done]
    done
    [/done]
    TAG:asdad.bwewk_stght=213.41808
    done
    [/done]
    done
    [/done]
    done
    [/done]
    TAG:asdad.bwewk_stght=3424.43408
    done
    [/done]
    done
    [/done]
    done
    [/done]
    done
    [/done]
    TAG:asdad.bwewk_stght=45424.43308

do note that everything after the TAG: portion can be different every time, different in length and in characters however it will always start with TAG:

So the end result I am after is

    3
    6
    10

what I have got so far, I am able to count all lines that the string occurs on perfectly however unable to wrap my head around how to proceed from here to do what i am after.

     $count = (get-content out.txt | select-string -pattern "[/done]" -SimpleMatch).length | Write-Host

>Solution :

You can read and match lines using regex with a switch:

$index = 0
switch -Regex -File out.txt {
    # if line matches `[/done]`, increase index
    '\[/done\]' { $index++ }
    # if line starts with `TAG:`, output index
    '^TAG:' { $index }
}