preg_match('/^.{0,33}\x20/i', $stroka, $matches);
$newstroka = $matches[0];

function SelectFirst($size,$unit,$text)
{   
   [String]::Concat([Regex]::Matches($text,@{'sentences'="[^.!?]+[.!?]+\s*";'words'="\w+\W*\s*";'letters'="(\w|\W)"}[$unit])[0..$($size-1)])
}



function SelectFirst2($size,$unit,$path)
{
   ls $path *.txt | %{sc "$($_.directory)\short-$($_.name)" (SelectFirst $size $unit (gc $_.fullname))   }
}