I am using Centos 7 and installed Apache server with an index.html page in it, the situation is i want to restrict the access for different browsers such as Internet explorer, Chrome and allow using Firefox to access the index.html page, i've created a ".htaccess" file and made the necessary changes which i've written at the bottom of my thread. I googled that we can write using rewrite rules and tried a lot of them, but couldn't get the exact code which helps me to get what i'm looking for, so i'm hoping someone in this forum can help me with my coding, i've executed various ways such as

RewriteEngine on
RewriteCond "%{HTTP_USER_AGENT}" "^Mozilla/3.*"
RewriteRule "^index\.html" "nopage.html" [F]

RewriteEngine on
RewriteCond %{HTTP_USER_AGENT} \ Firefox/55 [NC]
RewriteRule ^ - [F,L]

RewriteEngine on
RewriteCond %{HTTP_USER_AGENT} Firefox [NC]
RewriteRule .* - [F,L]

RewriteEngine on
RewriteCond %{HTTP_USER_AGENT} ^Firefox/5\.0
RewriteRule - [L,R=403,E=Firefox]

RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} "MSIE 12.0" [NC,OR]
RewriteRule ^(.*)$ http://192.168.12.60/ [L,R=301]

Thanks in advance

If it's your server then the changes need to go in the actual configuration file for your virtual host. The .htaccess files are a relic from the mid 1990's when shared hosting was common and necessary but lacked any possibility of virtual hosts. So if you are following a guide that recommends .htaccess, it is sorely out of date. Try using the configuration file that corresponds to the virtual host you are using.

@OP

Regardless you're using .htaccess or the apache config files, you can use the following to allow access to index.html only for firefox:
Regards

Thank you @bathory for responding soon and thanks for your answer but unluckily when accessing the url of my apache server in Chrome, Firefox and Internet Explorer, it is showing the index.html page i've created, if you don't mind could you please explain what's happening in the code which you've given. thank you

The first step is hopefull self-evident: it enables the runtime URL re-writing capabilities. It only needs to be done once.

The second and third lines are defining the actual rewriting.

The RewriteCond directive sets up a pattern which when found triggers the subsequent RewriteRule As you can see in the pattern, !(.*)Firefox, it's looking for a HTTP request where the variable HTTP_USER_AGENT does not have the string "Firefox" The flags NC mean the pattern is sought without regard to case. The line might also be use like this:

The RewriteRule directive does a replacement of the URL based on the pattern given. It could probably be rewritten so:

The L flag says to stop rewriting with that. No more rewrites after the line with the L.

See the authoritative documentation for more details:

• RewriteCond
• RewriteRule

But have you moved your rewriting directives back into your virtual host's own configuration file and out of .htaccess yet?

Turbocapitalist has explained to you the rewrite code.
In fact it should give a 403 (Forbidden) error if the User-agent string does not contain "Firefox".
Perhaps you need to clear your browsers' cache to verify if it works.

If it still doesn't work, assuming that you used my code in a .htaccess, you need to check for the following:
- apache reads .htaccess files? You need an "AllowOverride All" directive for this.
- You put the .htaccess in the DocumentRoot of your apache server?

Thank you for your reply @Turbocapitalist, can you please guide me how to make it possible using the virtual hosts file, i guess we can try it using Allow and Deny policies but i'm not much sure about it, it could be more helpful if you come up with it and thank you for your time

Surely i'll check whatever the changes needed to be made @Turbocapitalist and will get back to you if there's any new update regarding this.

It's best for us and for you if we can get you standing on your own two feet.

Your re-write rules would go in the appropriate Apache2 (httpd) configuration file. If you are on CentOS 7 then you can find your Apache2 configuration files in the directory /etc/httpd/conf.d/ but if you've not added any files, then that is the place to start by creating one. Usually you make one file per virtual host. If you will only ever have one virtual host, then you are probably still using the default, which is /etc/httpd/conf/httpd.conf but it's more practical to plan ahead and make a separate virtual host file anyway. That way it's easy to expand when you need to.

.htaccess tricks and tips...Part I
.htaccess tricks and tips... Part II

for the code that does the deed.
This code, as stated should be in site.conf first (if accessible) and $DocumentRoot/ in .htacess if site.conf is not accessible.
Shared Hosting vs. Dedicated, or V{D,P}S

using .htaccess to do this is resource intensive and is not recommended.

Thanks a lot guys, found the solution for it, but little more help needed from you guys, we're using Firefox for Mozilla firefox, what should be written if we use Internet explorer? " MSIE " or " IE "

The user agent string used by the legacy browsers probably vary by version, so you may need several patterns. You may want to connect several RewriteCond directives using an [OR] flag.

Check your logs to see what those strings really are or else you will have to guess which ones from a database like the one here over User Agent Strings listed by Browser.