stud(2).pl

#!/usr/bin/perl

use strict;
use warnings;
use List::Util qw(sum);

my $par = shift;

sub foreachLine {
	my ($const, $finalize) = @_;
	while (<DATA>) {
		$const->($_);
	}
	$finalize->();
}

{
	#closure
	my @keep;

	sub constrain {
		my $student = shift;  # gets a line like "Raimon Grau 6.4"
		my ($qualif) = $student =~ m/ ([^ ]*)$/;
		push @keep, $student if ($qualif > $par);
	}

	sub end_do {
		my @a = map{
			my ($qualif) = m/ ([^ ]*)$/;
			$qualif
		} @keep;
		print sum(@a)/@a , "\n";
	}
}

foreachLine(\&constrain , \&end_do);

__DATA__
foo 6.3
bar 4.3
baz 8.3
quux 8.3