In the Caddyfile, a **matcher token** immediately following the directive can limit that directive's scope. The matcher token can be one of these forms:
1.**`*`** to match all requests (wildcard; default).
2.**`/path`** start with a forward slash to match a request path.
3.**`@name`** to specify a _named matcher_.
Matcher tokens are [usually optional](/docs/caddyfile/directives#matchers). If a matcher token is omitted, it is the same as a wildcard matcher (`*`).
#### Examples
This directive applies to [all](#wildcard-matchers) HTTP requests:
The wildcard (or "catch-all") matcher `*` matches all requests, and is only needed if a matcher token is required. For example, if the first argument you want to give a directive also happens to be a path, it would look exactly like a path matcher! So you can use a wildcard matcher to disambiguate, for example:
Path matcher tokens must start with a forward slash `/`.
[Path matching](/docs/caddyfile/matchers#path) is an exact match by default; you must append a `*` for a fast prefix match. Note that `/foo*` will match `/foo` and `/foo/` as well as `/foobar`; you might actually want `/foo/*` instead.
All matchers that are not comprised of a single path matcher or a wildcard matcher must be named matchers. This is a matcher that is defined outside of any particular directive, and can be reused.
This proxies only the requests that have a header field named "Connection" containing the word "Upgrade", and another field named "Upgrade" with a value of "websocket".
Like directives, named matcher definitions must go inside the site blocks that use them.
A named matcher definition constitutes a _matcher set_. Matchers in a set are AND'ed together; i.e. all must match. For example, if you have both a `header` and `path` matcher in the set, both must match.
By any [CEL (Common Expression Language)](https://github.com/google/cel-spec) expression that returns `true` or `false`.
As a special case, Caddy [placeholders](/docs/conventions#placeholders) (or [Caddyfile shorthands](/docs/caddyfile/concepts#placeholders)) may be used in these CEL expressions, as they are preprocessed and converted to regular CEL function calls before being interpreted by the CEL environment.
Match requests where handler returned error status code `404`, would be used in conjunction with the [`handle_errors` directive](/docs/caddyfile/directives/handle_errors).
-`root` defines the directory in which to look for files. Default is the current working directory, or the `root` [variable](/docs/modules/http.handlers.vars) (`{http.vars.root}`) if set (can be set via the [`root` directive](/docs/caddyfile/directives/root)).
-`split_path` will cause the path to be split at the first delimiter in the list that is found in each filepath to try. For each split value, the left-hand side of the split including the delimiter itself will be the filepath that is tried. For example, `/remote.php/dav/` using a delimiter of `.php` would try the file `/remote.php`. Each delimiter must appear at the end of a URI path component in order to be used as a split delimiter. This is a niche setting and is mostly used when serving PHP sites.
Because `try_files` with a policy of `first_exist` is so common, there is a one-line shortcut for that:
```caddy-d
file <files...>
```
An empty `file` matcher (one with no files listed after it) will see if the requested file—verbatim from the URI, relative to the [site root](/docs/caddyfile/directives/root)—exists.
Since rewriting based on the existence of a file on disk is so common, there is also a [`try_files` directive](/docs/caddyfile/directives/try_files) which is a shortcut of the `file` matcher and a [`rewrite` handler](/docs/caddyfile/directives/rewrite).
#### Examples:
Match requests where the path is a file that exists.
```caddy-d
file
```
Match requests where the path followed by `.html` is a file that exists, or if not, where the path is a file that exists.
Like `header`, but supports regular expressions. Capture groups can be accessed via placeholder like `{http.regexp.name.capture_group}` where `name` is the name of the regular expression (optional, but recommended) and `capture_group` is either the name or number of the capture group in the expression. Capture group `0` is the full regexp match, `1` is the first capture group, `2` is the second capture group, and so on.
Match requests where the Cookie header contains `login_` followed by a hex string, with a capture group that can be accessed with `{http.regexp.login.1}`.
Matches request by the `Host` header field of the request. It is not common to use this in the Caddyfile, since most site blocks already indicate hosts in the address of the site. This matcher is mostly used in site blocks that don't define specific hostnames.
Like `path`, but supports regular expressions. Capture groups can be accessed via placeholder like `{http.regexp.name.capture_group}` where `name` is the name of the regular expression (optional, but recommended) and `capture_group` is either the name or number of the capture group in the expression. Capture group `0` is the full regexp match, `1` is the first capture group, `2` is the second capture group, and so on.
Match requests where the path ends a 6 character hex string followed by `.css` or `.js` as the file extension, with capture groups that can be accessed with `{http.regexp.static.1}` and `{http.regexp.static.2}` for each part enclosed in `( )`, respectively.
By query string parameters. Should be a sequence of `key=value` pairs. Keys are matched exactly, case-sensitively. Values are matched exactly, but also support `*` to match any value.
