pat: Index | Files

package pat

import ""

Package pat implements a simple URL pattern muxer


Package Files


func Tail Uses

func Tail(pat, path string) string

Tail returns the trailing string in path after the final slash for a pat ending with a slash.


Tail("/hello/:title/", "/hello/mr/mizerany") == "mizerany"
Tail("/:a/", "/x/y/z")                       == "y/z"

type PatternServeMux Uses

type PatternServeMux struct {
    // NotFound, if set, is used whenever the request doesn't match any
    // pattern for its method. NotFound should be set before serving any
    // requests.
    NotFound http.Handler
    // contains filtered or unexported fields

PatternServeMux is an HTTP request multiplexer. It matches the URL of each incoming request against a list of registered patterns with their associated methods and calls the handler for the pattern that most closely matches the URL.

Pattern matching attempts each pattern in the order in which they were registered.

Patterns may contain literals or captures. Capture names start with a colon and consist of letters A-Z, a-z, _, and 0-9. The rest of the pattern matches literally. The portion of the URL matching each name ends with an occurrence of the character in the pattern immediately following the name, or a /, whichever comes first. It is possible for a name to match the empty string.

Example pattern with one capture:


Will match:


Will not match:


Example 2:


Will match:


Will not match:


A pattern ending with a slash will add an implicit redirect for its non-slash version. For example: Get("/foo/", handler) also registers Get("/foo", handler) as a redirect. You may override it by registering Get("/foo", anotherhandler) before the slash version.

Retrieve the capture from the r.URL.Query().Get(":name") in a handler (note the colon). If a capture name appears more than once, the additional values are appended to the previous values (see

A trivial example server is:

package main

import (

// hello world, the web server
func HelloServer(w http.ResponseWriter, req *http.Request) {
	io.WriteString(w, "hello, "+req.URL.Query().Get(":name")+"!\n")

func main() {
	m := pat.New()
	m.Get("/hello/:name", http.HandlerFunc(HelloServer))

	// Register this pat with the default serve mux so that other packages
	// may also be exported. (i.e. /debug/pprof/*)
	http.Handle("/", m)
	err := http.ListenAndServe(":12345", nil)
	if err != nil {
		log.Fatal("ListenAndServe: ", err)

When "Method Not Allowed":

Pat knows what methods are allowed given a pattern and a URI. For convenience, PatternServeMux will add the Allow header for requests that match a pattern for a method other than the method requested and set the Status to "405 Method Not Allowed".

If the NotFound handler is set, then it is used whenever the pattern doesn't match the request path for the current method (and the Allow header is not altered).

func New Uses

func New() *PatternServeMux

New returns a new PatternServeMux.

func (*PatternServeMux) Add Uses

func (p *PatternServeMux) Add(meth, pat string, h http.Handler)

Add will register a pattern with a handler for meth requests.

func (*PatternServeMux) Del Uses

func (p *PatternServeMux) Del(pat string, h http.Handler)

Del will register a pattern with a handler for DELETE requests.

func (*PatternServeMux) Get Uses

func (p *PatternServeMux) Get(pat string, h http.Handler)

Get will register a pattern with a handler for GET requests. It also registers pat for HEAD requests. If this needs to be overridden, use Head before Get with pat.

func (*PatternServeMux) Head Uses

func (p *PatternServeMux) Head(pat string, h http.Handler)

Head will register a pattern with a handler for HEAD requests.

func (*PatternServeMux) Options Uses

func (p *PatternServeMux) Options(pat string, h http.Handler)

Options will register a pattern with a handler for OPTIONS requests.

func (*PatternServeMux) Patch Uses

func (p *PatternServeMux) Patch(pat string, h http.Handler)

Patch will register a pattern with a handler for PATCH requests.

func (*PatternServeMux) Post Uses

func (p *PatternServeMux) Post(pat string, h http.Handler)

Post will register a pattern with a handler for POST requests.

func (*PatternServeMux) Put Uses

func (p *PatternServeMux) Put(pat string, h http.Handler)

Put will register a pattern with a handler for PUT requests.

func (*PatternServeMux) ServeHTTP Uses

func (p *PatternServeMux) ServeHTTP(w http.ResponseWriter, r *http.Request)

ServeHTTP matches r.URL.Path against its routing table using the rules described above.

Package pat imports 3 packages (graph) and is imported by 513 packages. Updated 2020-09-27. Refresh now. Tools for package owners.