PowerShell5. Modify ascii text file string with line number string is on. Switch and .NET framework or cmdlets & the pipeline? Which is faster?

Question

How to modify a string (LINE2 \"line number LINE2 is on\") in a windows ascii text file using search strings that are easy to read and easy to add/modify/delete using PowerS

Answer 1

Alternative solution:

$regex = [Regex]::new('^(.*? (?:AROUND LINE|LINE2) )\d+(.*)$', 'Compiled, IgnoreCase, CultureInvariant')
$lc = 0
$updatedLines = & {foreach ($line in [IO.File]::ReadLines($file)) {
    $lc++
    $m = $regex.Match($line)
    if ($m.Success) {
        $g = $m.Groups
        $g[1].Value + $lc + $g[2].Value
    } else { $line }
}}
[IO.File]::WriteAllLines($file, $updatedLines, [Text.Encoding]::ASCII)