Shell Programming and Scripting

awk -v block=5 -v cols=3 '

function init_max(    i) {
   for (i=1; i<=cols; i++)
      max[i] = $i;
}

function set_max(    i) {
   for (i=1; i<=cols; i++)
      if ($i > max[i])
         max[i] = $i;
}

function print_max(    i, out) {
   for (i=1; i<=cols; i++)
      out = out max[i] OFS;
   print out;
}

{
   if (count++ == 0)
      init_max();
   set_max();
   if (count >= block) {
      print_max();
      count = 0;
   }
}

END {
   if (count > 0)
      print_max();
}

' inputfile

1 L 3.2
2 F 6.5
3 J 8.4
4 E 5.1
5 A 4.2
6 U 2.2
7 O 6.9
8 H 4.5
9 D 2.3
10 R 21.3

5 L 8.4
10 U 21.3

awk '$c > m { m = $c; r = $0 }
!(NR % n) { print r; m = 0 }
' c=3 n=5 filename

$file=shift;
$rows=shift;
$col=shift;
open(FH,"<$file");
while(<FH>){
	@arr=split(" ",$_);
	$t=$arr[$col-1];
	$index= ((index $./$rows,".")==-1)?$./$rows: (int $./$rows)+1;
	if($t>=$max){
		$max[$index]=$_;
		$max=$t;
	}
	if($.%$rows==0){
		$max=0;
	}
}
close(FH);
for($i=0;$i<=$#max;$i++){
	print $max[$i];
}