Best way to have a formatted output with Perl

Here is a live example of Perl6::Form:

#!/usr/bin/perl

use Perl6::Form;

my @arr = (
    [1..8],
    [9..16],
    [17..24],
);

foreach my $line (@arr) {
    print form
        "{<<<<<} "x8,
        @{$line};
}

It will output:

1       2       3       4       5       6       7       8
9       10      11      12      13      14      15      16
17      18      19      20      21      22      23      24

I would look at formatting, but I would do it using Perl 6's (now Raku) Form.pm, which you can obtain as Perl6::Form for Perl 5.

The reason for this is that the format builtin has a number of drawbacks, such as having the format statically defined at compile time (i.e., building it dynamically can be painful and usually requires string eval), along with a whole list of other shortcomings, such as lack of useful field types (and you can't extend these in Perl 5).

You could use Perl's format. This is probably the "complicated" method that you don't understand, most likely because it gives you many options (left|center|right justification/padding, leading 0's, etc).

Perldoc Example:

Example:
   format STDOUT =
   @<<<<<<   @||||||   @>>>>>>
   "left",   "middle", "right"
   .
Output:
   left      middle    right

Here's another tutorial.

Working Example: (Codepad)

#!/usr/bin/perl -w    

use strict; 

   sub main{    
      my @arr = (['something1','something2','something3','something4','something5','something6','something7','something8']
                ,['else1'     ,'else2'     ,'else3'     ,'else4'     ,'else5'     ,'else6'     ,'else7'     ,'else8'     ]
                ,['another1'  ,'another2'  ,'another3'  ,'another4'  ,'another5'  ,'another6'  ,'another7'  ,'another8'  ]
                );
      
      for my $row (@arr) {
         format STDOUT =
@<<<<<<<<<<<<  @<<<<<<<<<<<<  @<<<<<<<<<<<<  @<<<<<<<<<<<<  @<<<<<<<<<<<<  @<<<<<<<<<<<<  @<<<<<<<<<<<<  @<<<<<<<<<<<<  
         @$row
.
         write;
      }

   }    
       
   main();   

printf

    printf "%-11s %-11s %-11s %-11s %-11s %-11s %-11s %-11s\n",
            $column1, $column2, ..., $column8;

Change "11" in the template to whatever value you need.