The relevant passage of perlform is

Inside of an expression, the whitespace characters \n, \t and \f are c
+onsidered to be equivalent to a single space. Thus, you could think o
+f this filter being applied to each value in the format:

 $value =~ tr/\n\t\f/ /;

The remaining whitespace character, \r, forces the printing of a new l
+ine if allowed by the picture line.
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You can achieve the output you want by translating the \n's to \r's

#!/bin/env perl -w
use strict;

my $cookie="Climb the mountains\nand get their good tidings.\nNature's
+ peace will flow into you\nas sunshine flows into trees.\n";
my $author="-John Muir\n";
$cookie =~ tr[\n][\r];
$: = "- ";
format STDOUT =
        @|||||||||||||||||||||||||||||||||||||||||||||||||
        "------------------------------------------------"
~~     ^<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
        $cookie
        @||||||||||||||||||||||||||||||||||||||||||||
        $author
        @|||||||||||||||||||||||||||||||||||||||||||||||||
        "------------------------------------------------"
.
write STDOUT;
__END__
         ------------------------------------------------
       Climb the mountains
       and get their good tidings.
       Nature's peace will flow into you
       as sunshine flows into trees.
                         -John Muir
         ------------------------------------------------
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Though a couple of other adjustments are required.

Thanks, that worked magnificiently!.

However I notice something surprising -- if the width of the $cookie format line is increased beyond a certain limit ( 63 in the above example ), the last line is gobbled up completely when being printed!

The perlform documentation says at the very end - "The remaining whitespace character, \r, forces the printing of a new line if allowed by the picture line.". Any idea if this is responsible for what's happening ?

I can get by with adjusting the format width to the correct amount, but it would be nice to know the reason anyhow.

    use Text::Reform;

    print form
    "         -------------------------------------------------",
    "         [[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[",
              $cookie,
    "         ||||||||||||||||||||||||||||||||||||||||||||",
              $author,
    "         -------------------------------------------------";
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