while (1) {
   print 'Please enter a word: ';
   chomp(my $word = <STDIN>);
   last if $word =~ /^\s*$/;
   print "You entered '$word'\n";
}

##</code><code>##

# Had to duplicate the prompt, <read>, and chomp.
# Duplication is bad!
# Use the DRY principle: [D]on't [R]epeat [Y]ourself!
my $word;
print 'Please enter a word: ';
chomp($word = <STDIN>);
while ( $word !~ /^\s*$/ ) {
   print "You entered '$word'\n";

   print 'Please enter a word: ';
   chomp($word = <STDIN>);
}

##</code><code>##

# Had to add `not defined $word` to handle the special case
# during the first time through the loop. Very Ugly!
# Had to duplicate code `$word !~ /^\s*$/` to prevent the
# final ENTER from printing "You entered ''" as it exits
# the loop.
my $word;
while ( ( not defined $word ) or ( $word !~ /^\s*$/ ) ) {
   print 'Please enter a word: ';
   chomp($word = <STDIN>);
   if ( $word !~ /^\s*$/ ) {
       print "You entered '$word'\n";
   }
}

##</code><code>##

# Instead of using `not defined $word`, I force
# non-whitespace into $word.
# Still very ugly.
# Still had to duplicate code `$word !~ /^\s*$/`
my $word = 'JunkToPreventFailingTheFirstLoop';
while ( $word !~ /^\s*$/ ) {
   print 'Please enter a word: ';
   chomp($word = <STDIN>);
   if ( $word !~ /^\s*$/ ) {
       print "You entered '$word'\n";
   }
}

##</code><code>##

# Still had to duplicate code `$word !~ /^\s*$/`
my $word;
do {
   print 'Please enter a word: ';
   chomp( $word = <STDIN> );
   if ( $word !~ /^\s*$/ ) {
       print "You entered '$word'\n";
   }
} while $word !~ /^\s*$/;

##</code><code>##

sub prompt {
    my ($prompt_string) = @_;
    print $prompt_string;
    my $input = <STDIN>;
    chomp $input;
    return $input;
}
# Success!
while ( my $word = prompt('Please enter a word: ') ) {
    print "You entered '$word'\n";
}

##</code><code>##

use IO::Prompt;
while (my $word=prompt 'Please enter a word: ', -while => qr/\S/) {
    print "You entered '$word'\n";
}