open (F, "log.txt") or die "Couldn't open: $!";

while (1) {
	my $line1 = <F>; # Get a line
	my $line2 = <F>; # Get another line

	last unless defined($line1); # bail if there's no data

	#... now you can filter what you want here,
	# match, print, push whatever. All the data you 
	# care about is in $line1 and $line2
}