First I would get the accept_language, either like the first poster mentioned, or simply using: 
$ENV{HTTP_ACCEPT_LANGUAGE}

[download]

The second step, is I would override your path for your templates. Both HTML::Template and Template::Toolkit allow you to specify an arrayref of paths to look for your templates. I would unshift your language override directory on to the front of your path arrayref (in HTML::Template - INCLUDE_PATH in TT). That way, it will find you language override templates - but will fall back to your default templates if a language override can't be found. 

my $base_dir_abs = "/var/www/templates";
my $default_lang = 'en';
my $lang         = lc $ENV{'HTTP_ACCEPT_LANGUAGE'}
my @dirs = ("$base_dir_abs/$default_lang");

if ($lang
    && $lang ne $default_lang
    && $lang =~ /^(\w{2})/ # may look like "en-us"
    && -d "$base_dir_abs/$1") {
    unshift @dirs, "$base_dir_abs/$1";
}

my $tt = Template->new({
    INCLUDE_PATH => \@dirs
});
$tt->process($file);

OR

my $ht = HTML::Template->new(
    filename => $file,
    path     => \@dirs,
);

[download]


Update: adding specification for how to store your content. 


# Your directory structure may look like
/var/www/templates/en/my_cgi/index.html
/var/www/templates/en/my_cgi/step2.html
/var/www/templates/en/my_cgi/step3.html
/var/www/templates/en/another_cgi/index.html

/var/www/templates/sp/my_cgi/index.html
/var/www/templates/sp/my_cgi/step2.html
/var/www/templates/sp/another_cgi/index.html

[download]

If the CGI is passed HTTP_ACCEPT_LANGUAGE of sp and $file = 'my_cgi/index.html'; then you'll get /var/www/templates/sp/my_cgi/index.html. If you call it with a language other than "sp" then you'll always get /var/www/templates/en/my_cgi/index.html (well - always until you override my_cgi/index.html in that other language).

Likewise for templates such as my_cgi/step3.html that don't exist in sp - you'll always fall back and get en/my_cgi/step3.html.

my @a=qw(random brilliant braindead); print $a[rand(@a)];

In reply to Re: content negotiation with Apache/cgi by Rhandom
in thread content negotiation with Apache/cgi by punkish

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.