Here's my try at it:

#!/usr/bin/perl

my $max_str_len = 12;

my $string = "This is a test message";

$string =~ tr/ / /s;
$string =~ s/^\s*//;
$string =~ /(.{0,$max_str_len})(\s|$)/;

my $trunc_string = $1;

my @words = split /\s+/, $trunc_string;

print "Word: ", $_, "\n" foreach @words;
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