Second example in the article is for use in htaccess file in /blog/ folder.

Please make that more clear.

There's a third bit of code you should include - for when the index.php file is in the /blog/ folder and the redirect code is placed in the htaccess file in the site root.

Those are the three possible site configurations.

Code seen in the comments...

RewriteCond %{REQUEST_URI} /(index)|(home)(..{3,4})?$ [NC]
RewriteRule ^([^/]+/)+ http://www.askapache.com/$1? [R=301,L]

There are multiple problems with the above code. Do not use it. Condition runs for every request, you should also include the index|home test in the Rule pattern for better efficiency. In the condition, repeat the same pattern with opening anchor and matching for folder levels. No extension or closing anchor specified for index, only for home. Unnecessary brackets, or brackets in wrong place.

RewriteRule ^(.*)$ $1.php [L]

Add a slash before the $1 otherwise you leave your server open to path injection hacks.

RewriteCond %{HTTP_HOST} www.example.com [NC]
RewriteRule ^(.*)$ http://example.com/$1 [R=301,NC]

The above code fails to redirect many non-canonical URLs, such as www request that include port number, etc. Try:

RewriteCond  %{HTTP_HOST}  !^(www.example.com)?$
RewriteRule  (.*)  http://www.example.com/$1 [R=301,L]

RewriteRule ^index.php$ - [L]

What exactly do the following control?

" ^"      =
""       =
"$ -"    =
"[L]"    =

Thank you for your help
Arthur

RewriteRule ^index.php$ - [L]

Someone suggested that I am blocking the site from the Google bot and my site will not show up in search engines?

Thanks,

It's just a difference where one has a more inclusive regex. The reason is that while Google's robot may correctly interpret either, some robots from other search engines may need the other. Always go with Google!