Rewrite URL add parameter with htaccess

Question

How can I add parameter to this url:

http://example.com/?p=10455

for ex:

http://example.com/100/?p=10455

and it will redirect to the same location, only with additional parameter (num=100)?

Answer 1

Like this

RewriteRule ^([0-9]+)/$ index.php?num=$1 [L,QSA]

Answer 2

Place this rule in your DOCUMENT_ROOT/.htaccess file:

RewriteEngine On

RewriteCond %{QUERY_STRING} (^|&)p=10455(&|$) [NC]
RewriteRule ^$ /100/ [L]