First question: Is your htaccess (the real one in . leading dot) recognized by the MAMP installation? If not, you will have to be brave and edit the config file. Since it's all happening on your own computer, go ahead and say
AllowOverride All
for the highest possible directory (<Directory /some-name-here> section). This may depend on OS; I had one form that didn't work in 10.6 but does in 10.9.
are you saying I should use full urls?
That would kinda blow the point of even using MAMP, because you want your local files to be exactly the same as your "live" files. Leading slash always means "stay on the present host", whatever it may be.
I tried the full url on that link and while it brought up the page without the extension on it the page was empty and had a not-found message, so must be a 404. This is odd as I have a custom 404 error page and this is not it.
By "brought up the page" do you simply mean that the browser's address bar ended up showing the intended URL? It sounds as if you got the generic Apache 404 message, which is what MAMP will give you. Possible reasons for your custom 404 page not to show up include:
-- you don't have it in the same location (relative to the root) on your local site as on your live site
-- the htaccess file you're using doesn't include the ErrorDocument directive
-- as discussed earlier, your MAMP installation doesn't recognize htaccess files (assuming there is one, and it contains the ErrorDocument line)
The form
http:/ /filename
will never get you to /filename, because your computer is now looking for a website called "filename" -- and, understandably, not finding it. That's why the browser says "server not found". What you need instead is
/filename
with leading slash. This will work if and only if "filename" is side-by-side with your domain's index page.
If the physical file has no extension, browsers won't now what to do with it: treat it as html? serve as a plain-text file? try to parse with some language? That's why you installed MAMP in the first place, right? So you could say something like
RewriteRule ^([^.]+)$ /$1\.html [L]
and try it out locally. This should work identically on MAMP as on your live site-- always assuming that the htaccess is recognized in the first place.
Yes, of course you can disregard htaccess and proceed directly to the config file now that you've got one. But I don't think it is the most appropriate way to proceed (other thread) in most situations.