@Swanny007 and Tangor,
Thank you guys for responding.
Agreed. Using Duckduckgo or Bing is a great idea, because when without much thinking I use Google, pretty much ALL I get is 30 or 40 articles on Google's own, highly advertised custom search service. And naturally they tell me how great it is.
And, of course Google's Custom Site Search service is not that great! Firstly it's NOT ad-free! And, secondly, the results you get are NOT even accurate!
In the last 2 or 3 days I've looked at Matt's Script Archive (in CGI). And the "Simple Search" project of the 'London Perl Mongers' (in Perl). However, both of them appear to be outdated or obsolete.
I've also searced sourceforge.net, fsf.org, downloads.com, cnet.com, and many others. However, I've had no luck so far. There is only one program, called SSEP, that I'm considering at the moment. However, I'm reluctant to go ahead and use it, because it's NOT popular, with NO user feedback, and NO reviews.
I've also looked at up to 15 other "site search" programs from all over the Internet. However, ALL of them turned out to be annoying liabilities. Either because they turned out to be NOT ad-free. Or because they wanted my money, per month, every month.
Agreed. Size can be an issue, too. However, when on my desktop there is a free 'far.exe' app that is able to do a folder search on my desktop, and if it can do it in two seconds or less, then why should it take longer, and why should it cost me big bucks, when the only real difference seems to be that the same or a similar operation is performed on the server's side?