use strict;

my @matrix;

$matrix[0][0] = 'A1a1'; #sort by this column 
$matrix[0][1] = 'img1';
$matrix[0][2] = 'x123';
$matrix[0][3] = 'y123';

$matrix[1][0] = 'A1a2';
$matrix[1][1] = 'img2';
$matrix[1][2] = 'x123';
$matrix[1][3] = 'y456';

$matrix[1][0] = 'A1a12';
$matrix[1][1] = 'img3';
$matrix[1][2] = 'x456';
$matrix[1][3] = 'y789';

$matrix[2][0] = 'A10a1';
$matrix[2][1] = 'img4';
$matrix[2][2] = 'x456';
$matrix[2][3] = 'y123';

$matrix[3][0] = 'A12a1';
$matrix[3][1] = 'img5';
$matrix[3][2] = 'x456';
$matrix[3][3] = 'y456';

my @sorted_matrix = sort {$a->[0] <=> $b->[0] || $a->[0] cmp $b->[0] } @matrix;

for my $i ( 0 .. $#sorted_matrix ) {
    for my $j ( 0 .. $#{ $sorted_matrix[$i] } ) {
        print "$i $j -> $sorted_matrix[$i][$j]\n";
    }
    print "\n";
}