Have a look at the formline function and the accumulator $^A.

Here is a short, seasonal, example that centres the elements of an array on separate lines. The format is built dynamically.

#!/usr/bin/perl -w

use strict;

my @a = qw(* *** ***** ******* ********* *);

formline(('@'.('|'x72)."\n")x@a, @a);
print $^A;
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--
John.