If each row of output is built from data in multiple keys of the hash (per your test code), then I don't think you have any choice but to roll your own code that traverses everything and builds up the output.

If you've got arbitrarily many keys in %hash, then you'll likely want something like this:

use strict;
use warnings;

my %hash;

$hash{col1} = [qw(a b c d e)];
$hash{col2} = [qw(1 2 3 4 5)];
$hash{col3} = [qw(q r s t u)];

# Change this so that the keys of %hash
# show up in the order you want them,
# in the output.                                 

my @keys = sort keys %hash;

# Assumes every key of %hash is an
# arrayref with the same number of
# elements in it.  Also note that
# this code destroys %hash, as
# it goes along.  If you don't want
# that, make a copy first.

print join(",", @keys), "\n";

my $ref_key = $keys[0];

while (@{ $hash{$ref_key} })
{
    my @line;

    for my $key (@keys)
    {
        push @line, shift(@{ $hash{$key} });
    }

    print join(",", @line), "\n";
}

[download]

In reply to Re^2: printing columns of data by klassa
in thread printing columns of data by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.