Analyze the rewriting rules of CI, the CodeIgniter framework, under Nginx_PHP tutorial

server {

listen 80;
server_name www.ci.com;
location / {
root d:/www/Codeigniter_2.0.1/;
index index.html index.htm index.php;
rewrite ^/$/index.php last;
rewrite^/(?!index.php|robots.txt|images|js|styles)(.*) $ /index.php/$1last;
}
location ~^(.+.php)(.*)$ {
root D:/www/Codeigniter_2.0.1/;
fastcgi_index index .php;
fastcgi_split_path_info ^(.+.php)(.*)$;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

fastcgi_param PATH_INFO $fastcgi_path_info;
fastcgi_param PATH_TRANSLATED $document_root$fastcgi_path_info; fastcgi_pass 127.0.0.1:9002;
include fastcgi_params;
}
}