NginX: rewrite backslashes to Forward-slashes - nginx

Question

I want to write NginX rewrite rule to convert all Backslashes to forward-slashes.
Something exactly like: Using .htaccess to replace backslash in URL with forward-slash
however, I am working in NginX while above link refers to Apache.
I migrated my application from Windows IIS to Linux Tomcat and hence I need to get this done.
My URL has multiple Backslashes which gets resolved fine in IE and Chrome but Firefox is resolving them to its Unicode %5C and hence I need to rewrite.
My sample URL in WIndows/IIS: https://doman.com/company/.\images\company\companylogo.png
When I moved stuff to Linux/Tomcat, above URL works in Chrome and IE, but Firefox is converting above backslashes to %5C. So Firefox is trying to resolve: https://doman.com/company/.%5Cimages%5Ccompany%5Ccompanylogo.png
And needless to say, Firefox fails to load the image.
Here is what I tried so far in my nginX configuration (Once statement at a time)):
rewrite \ / permanent;
rewrite \\ \/ permanent; # with escaping thinking it might help
rewrite (.*)\(.*)\(.*)\(.*) $1/$2/$3/$4 permanent;
rewrite (.*)\(.*)\(.*)\(.*) $1\/$2\/$3\/$4 permanent;
Howcer , none seem to work and last 2 statements are throwing NginX configuration Error.
Any pointers would be of great help. There are thousands such URLs and I cannot imagine of converting all of them into Forward-Slash'd style.

Answer 1

Finally, I figured it out myself.
First off, in NginX, a backslash needs to be escaped twice. Nginx Uses Lua launguage module extensively for parsing request. So, NginX config parser as well as Lua module will strip off the escaping backslashes. Hence need to escape it twice.
This is wrong: \\
This is Correct: \\\
This part bugged me for 2 days as I was following typical PCRE standards for escaping characters and NginX would throw regex error at me.
More about this behaviour is explained here: http://wiki.nginx.org/HttpLuaModule#Special_PCRE_Sequences
Now, over to my question:
Source URL: https://domain.com/company/.\images\company\companylogo.png
Redirected URL: https://domain.com/company/./images/company/companylogo.png
I wanted to convert all \ to / in above URL. So, for this purpose, below rewrite rule is needed:
rewrite ^/(.+)\\\(.+)\\\(.+)\\\(.+)$ /$1/$2/$3/$4 redirect;
Above rule will do a single redirect (HTTP Code 302) and will get all the three \ converted to /.
However, If you have varying number of \ in the URL, then above rule may(not) work. Hence in that case, use below rule to convert ALL \ to /
rewrite ^/(.+)\\\(.+)$ /$1/$2 redirect;
Please note that, with above rule in place multiple redirects (HTTP Code 302) will happen causing some latency. The number of redirects will be equal to number of \ in the source URL. This would work on my URL too. But then it would have done the redirect for 3 times (as I have 3 backslashes in my URL). So, I am good with the 1st rule I mentioned above.
Nonetheless, I had a great learning all along and I understand NginX better now.
Here are few (out of hundreds of) links which helped solving this issue:
http://wiki.nginx.org/HttpLuaModule
https://blog.engineyard.com/2011/useful-rewrites-for-nginx
http://nginx.org/en/docs/http/ngx_http_core_module.html#location
http://blog.rackcorp.com/2010/05/nginx-location-and-rewrite-configuration-made-easy/
http://www.cyberciti.biz/faq/unix-linux-bsd-nginx-redirect-url-http-301-status-code/