use strict;
use warnings;

sub printdata {
	my $out = shift;
	my $data = shift;
	$$data{"User-Agent"} //= "--";
	print $out join "|", @$data{ ( "Arrival Time", "From", "To", "User-Agent" ) };
	print $out "\n\n";
	%$data = ();
}

open my $out, ">", "tmp.txt";

my %data;
my ($item, $value);
print $out "Arrival Time|From|To|User-Agent\n\n";
while(<DATA>){
	chomp;
	next unless ($item, $value) = /^(.*?): (.*)/;
	printdata $out, \%data if $item eq "Arrival Time" and %data;
	$data{$item} = $value;
}
printdata $out, \%data;