Perl for Web Site Management

Inserting the Links

As mentioned earlier, the rest of that long if-elsif section simply repeats, with minor variations, the same process of creating a $link_string suitable for the page currently being processed by the enclosing foreach loop. Down at the bottom of that foreach loop, after the long if-elsif section, comes the following chunk of code:

if ($link_string) {
    $link_string =~ s/<BR>\n$//;
    $link_string = "$link_start$link_string$link_end";
}

$link_string .= "\n$more_string\n";

This does a cleanup on the $link_string variable, removing a trailing <BR>\n it might have in the case of certain types of pages. It also appends another variable to it, called $more_string, that might have received some content in the case of certain kinds of pages. You can examine the if-elsif block to see how those cases work, if you’re curious, but we won’t be discussing them here.

Finally, we use a substitution operation to take the $made_page variable (which you’ll recall contains the newly re-created version of the current page) and insert the cleaned-up $link_string variable into it just below the <!--end content--> comment. Then we use the &write_page routine to replace the actual version of the page on the web site with our new version of it:

$made_page =~ 
    s{(<!--\s*end\s+content\s*-->)}{$1\n\n$link_string}i;

&write_page($path, $made_page) or die "&write_page failed";

And that’s it. By running this script when the site’s collection of student and leader pages has changed, we can update all ...