my %count;
while (my $line_1 = <$INFILE_1>){
    $line_1 =~ s/\s+$//;
    $count{$line_1}++;
}
while (my $line_2 = <$INFILE_2>){
    $line_2 =~ s/\s+$//;
    print $line_2, "\n" if $count{$line_2};
}
# untested