Redirection loop problem: old-style urls to new user-friendly url

I'm tryin' to replace old-style urls to the new one user-friendly only using .htaccess

e.g. domain.com/dir/?id=101 -> domain.com/dir/robots

It should be accessed from old links (?id=...) by users or searchbots and redirected to the new one with 301 status code and of course it s开发者_StackOverflow社区hould be accessed from the new url.

my .htaccess:

Options +FollowSymlinks
RewriteEngine on
RewriteBase /dir/

RewriteRule ^robots/?$ ?id=101 [L]

RewriteCond %{QUERY_STRING} ^id=101$
RewriteRule ^$ robots? [R=301,L]

It returns redirection loop, obviously.

Unfortunately i can not modify CMS engine, so the only solution is to do this with .htaccess rules.

I've googled a lot but didn't found any working solution for this issue.

Any ideas?

Thanks!

SOLVED

Ok, a little bit of random magic and i found solution:

RewriteRule ^robots/?$ ?id=101 [L]

RewriteCond %{ENV:REDIRECT_STATUS} !=200
RewriteCond %{QUERY_STRING} ^id=101$
RewriteRule ^$ robots? [R=301,L]

Important: No space after !=200 in condition RewriteCond %{ENV:REDIRECT_STATUS} . with space it doesnt work.

Options +FollowSymlinks
RewriteEngine on
RewriteBase /dir/

RewriteRule ^robots/?$ ?id=101 [L]

RewriteCond %{QUERY_STRING} ^/id=101$
RewriteRule ^(.*)$ http://%{HTTP_HOST}/dir/robots? [R=301,L]