Added 3 test

05 .. unpack, using List::MoreUtils's natatime
06 .. unpack again
07 .. yours

                   s/iter 02_split1 05_unpack_natatime 06_unpack_map 04_unpack 03_split2 07_unpack_2
02_split1            6.38        --               -13%          -16%      -35%      -42%        -50%
05_unpack_natatime   5.55       15%                 --           -4%      -25%      -33%        -43%
06_unpack_map        5.34       19%                 4%            --      -22%      -31%        -40%
04_unpack            4.18       53%                33%           28%        --      -11%        -24%
03_split2            3.70       72%                50%           44%       13%        --        -14%
07_unpack_2          3.18      100%                74%           68%       31%       16%          --
01_substr            2.70      136%               105%           98%       55%       37%         18%

sub test5{ #with natatime
    use List::MoreUtils qw/natatime/;
    $href={};

    open(my $fh, "<", "04_A10A10A4.ascii") or die $!;
    local $/= undef;

    my $lt = natatime(3, unpack( '(a10a10a4)*', <$fh>));
    while( my @rec=$lt->() ){
        push @{ $href->{ $rec[0] } }, [ @rec[ 1, 2 ] ]
    }
    close $fh;
}
sub test6{
    $href={};

    open(my $fh, "<", "04_A10A10A4.ascii") or die $!;
    local $/= undef;

    my $i=1;
    my($s1,$s2);
    map {
        $s1=$_ if $i % 3 == 1;
        $s2=$_ if $i % 3 == 2;
        if( $i % 3 == 0){
            push @{ $href->{$s1} }, [$s2, $_];
        }
        $i++;
    }unpack( '(a10a10a4)*', <$fh> );
    close $fh;
}
sub test7 {
    my %hash=();
    open(my $fh, "<", "04.txt") or die $!;
    while( <$fh> ) {
        my( $k, @v ) = unpack( 'a10a10a4', $_ );
            push @{ $hash{ $k } }, \@v
    }
    close $fh;
}
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