perl -le 'my $n = shift; die q{Please provide a positive number.} if ($n < 0); print q{*} x $n; if ($n > 1) { foreach (2 .. $n - 1) { print q{*}, q{ } x ($n - 2), q{*}; } print q{*{ x $n; }'

The above snippet takes a number afterward to select the size. In the case of nothing given, $n gets a value of 0. The q{*} x $n will give nothing if $n is 0, or $n asterisks. The if statement prevents the loop for the sides and printing a bottom if $n is 1. The loop is triggered only if $n - 1 is greater than 2 (ie, 3 or more), and prints only the asteristks on either edge, producing the "hole" in the middle.

Hope that helps.

In reply to Re^3: Printing a hollow square of Asterisks by atcroft
in thread Printing a hollow square of Asterisks by Rafter

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