What are the matching rules for locations in nginx?

The matching rules for nginx’s location directive are as follows:

1. Exact match (=): If the URI matches the specified location exactly, then use that location. For example, location = /test will only match requests with URI /test.
2. Prefix matching (^~): If the URI starts with the specified location, use that location. This rule takes precedence over regular expression matching. For example, the location ^~ /images/ will match URIs that start with /images/, such as /images/logo.png.
3. Regular expression matching (~ and ~*): Matching using regular expressions. ~ indicates case sensitivity, ~* indicates case insensitivity. For example, location ~ \.(jpg|jpeg|png)$ will match URIs ending with .jpg, .jpeg, or .png.
4. Longest prefix match: If there is no exact match, prefix match, or regular expression match, then the location with the longest prefix match will be used. For example, location / will match any URI.

Note: When multiple locations meet the matching criteria, the first matched location will be used. Therefore, it is important to pay attention to the order of the matching rules.