All,
Assuming you have a file called 'words.txt' that contains 1 word per line, this code can be used to generate a random puzzle.

#!/usr/bin/perl
use strict;
use warnings;
use List::Util 'shuffle';

my $num_cat = 20;
my $max_len = 10;
my $min_sol = 6;
my $max_sol = 30;

my @word;
open(my $fh, '<', 'words.txt') or die "Unable to open 'words.txt' for 
+reading: $!";
while (<$fh>) {
    tr/a-z//cd;
    next if length($_) > $max_len;
    push @word, $_;
}
@word = shuffle(@word);

for my $cat (1 .. $num_cat) {
    my $count = int(rand ($max_sol - ($min_sol - 1))) + $min_sol;
    my @cat = splice(@word, 0, $count);
    print "@cat\n";
}
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