I want to write nginx rewrite rules for clean URLs.

Everytime the user hits http://domain.com/abc/12/16/abc-def-ghi I need to execute domain.com/abc.php?a=12&b=16&c=abc-def-ghi.

Now my regex is right as per rubular: ^\/abc\/(\d+)\/(\d+)\/(\w+\S+)$
http://rubular.com/regexes/11063

and rule is

if (!-e $request_filename) {
rewrite ^\/abc\/(\d+)\/(\d+)\/(\w+\S+)$ abc.php?a=$1&b=$2&c=$3 last;

}

But it is giving "No input File specified". I cant find what the problem is?