use strict;
use warnings;

open_log();
a();
b();
close_log();

sub a {
	logging("Entering a\n");
	logging("Entering a\n");
}

sub b {
	logging("Entering b\n");
	logging("Entering b\n");
}

sub logging {
	print LOG shift;
}

sub open_log {
	open(LOG, ">", "log");
}

sub close_log {
	close LOG;
}

##</code><code>##

Entering a
Entering a
Entering b
Entering b