Package url


Package url parses URLs and implements query escaping.


Package files


func PathEscapeSource

func PathEscape(s string) string

PathEscape escapes the string so it can be safely placed inside a URL path segment.

func PathUnescapeSource

func PathUnescape(s string) (string, error)

PathUnescape does the inverse transformation of PathEscape, converting %AB into the byte 0xAB. It returns an error if any % is not followed by two hexadecimal digits.

PathUnescape is identical to QueryUnescape except that it does not unescape '+' to ' ' (space).

func QueryEscapeSource

func QueryEscape(s string) string

QueryEscape escapes the string so it can be safely placed inside a URL query.

func QueryUnescapeSource

func QueryUnescape(s string) (string, error)

QueryUnescape does the inverse transformation of QueryEscape, converting %AB into the byte 0xAB and '+' into ' ' (space). It returns an error if any % is not followed by two hexadecimal digits.

type ErrorSource

Error reports an error and the operation and URL that caused it.

type Error struct {
        Op  string
        URL string
        Err error

func (*Error) ErrorSource

func (e *Error) Error() string

func (*Error) TemporarySource

func (e *Error) Temporary() bool

func (*Error) TimeoutSource

func (e *Error) Timeout() bool

type EscapeErrorSource

type EscapeError string

func (EscapeError) ErrorSource

func (e EscapeError) Error() string

type InvalidHostErrorSource

type InvalidHostError string

func (InvalidHostError) ErrorSource

func (e InvalidHostError) Error() string

type URLSource

A URL represents a parsed URL (technically, a URI reference). The general form represented is:

scheme://[[email protected]]host/path[?query][#fragment]

URLs that do not start with a slash after the scheme are interpreted as:


Note that the Path field is stored in decoded form: /%47%6f%2f becomes /Go/. A consequence is that it is impossible to tell which slashes in the Path were slashes in the raw URL and which were %2f. This distinction is rarely important, but when it is, code must not use Path directly.

Go 1.5 introduced the RawPath field to hold the encoded form of Path. The Parse function sets both Path and RawPath in the URL it returns, and URL's String method uses RawPath if it is a valid encoding of Path, by calling the EscapedPath method.

In earlier versions of Go, the more indirect workarounds were that an HTTP server could consult req.RequestURI and an HTTP client could construct a URL struct directly and set the Opaque field instead of Path. These still work as well.

type URL struct {
        Scheme     string
        Opaque     string    // encoded opaque data
        User       *Userinfo // username and password information
        Host       string    // host or host:port
        Path       string
        RawPath    string // encoded path hint (Go 1.5 and later only; see EscapedPath method)
        ForceQuery bool   // append a query ('?') even if RawQuery is empty
        RawQuery   string // encoded query values, without '?'
        Fragment   string // fragment for references, without '#'


package main

import (

func main() {
	u, err := url.Parse("http://bing.com/search?q=dotnet")
	if err != nil {
	u.Scheme = "https"
	u.Host = "google.com"
	q := u.Query()
	q.Set("q", "golang")
	u.RawQuery = q.Encode()

Example (Opaque)

package main

import (

func main() {
	// Sending a literal '%' in an HTTP request's Path
	req := &http.Request{
		Method: "GET",
		Host:   "example.com", // takes precedence over URL.Host
		URL: &url.URL{
			Host:   "ignored",
			Scheme: "https",
			Opaque: "/%2f/",
		Header: http.Header{
			"User-Agent": {"godoc-example/0.1"},
	out, err := httputil.DumpRequestOut(req, true)
	if err != nil {
	fmt.Println(strings.Replace(string(out), "\r", "", -1))

Example (Roundtrip)

package main

import (

func main() {
	// Parse + String preserve the original encoding.
	u, err := url.Parse("https://example.com/foo%2fbar")
	if err != nil {

func ParseSource

func Parse(rawurl string) (*URL, error)

Parse parses rawurl into a URL structure. The rawurl may be relative or absolute.

func ParseRequestURISource

func ParseRequestURI(rawurl string) (*URL, error)

ParseRequestURI parses rawurl into a URL structure. It assumes that rawurl was received in an HTTP request, so the rawurl is interpreted only as an absolute URI or an absolute path. The string rawurl is assumed not to have a #fragment suffix. (Web browsers strip #fragment before sending the URL to a web server.)

func (*URL) EscapedPathSource

func (u *URL) EscapedPath() string

EscapedPath returns the escaped form of u.Path. In general there are multiple possible escaped forms of any path. EscapedPath returns u.RawPath when it is a valid escaping of u.Path. Otherwise EscapedPath ignores u.RawPath and computes an escaped form on its own. The String and RequestURI methods use EscapedPath to construct their results. In general, code should call EscapedPath instead of reading u.RawPath directly.

func (*URL) HostnameSource

func (u *URL) Hostname() string

Hostname returns u.Host, without any port number.

If Host is an IPv6 literal with a port number, Hostname returns the IPv6 literal without the square brackets. IPv6 literals may include a zone identifier.

func (*URL) IsAbsSource

func (u *URL) IsAbs() bool

IsAbs reports whether the URL is absolute. Absolute means that it has a non-empty scheme.

func (*URL) MarshalBinarySource

func (u *URL) MarshalBinary() (text []byte, err error)

func (*URL) ParseSource

func (u *URL) Parse(ref string) (*URL, error)

Parse parses a URL in the context of the receiver. The provided URL may be relative or absolute. Parse returns nil, err on parse failure, otherwise its return value is the same as ResolveReference.

func (*URL) PortSource

func (u *URL) Port() string

Port returns the port part of u.Host, without the leading colon. If u.Host doesn't contain a port, Port returns an empty string.

func (*URL) QuerySource

func (u *URL) Query() Values

Query parses RawQuery and returns the corresponding values.

func (*URL) RequestURISource

func (u *URL) RequestURI() string

RequestURI returns the encoded path?query or opaque?query string that would be used in an HTTP request for u.

func (*URL) ResolveReferenceSource

func (u *URL) ResolveReference(ref *URL) *URL

ResolveReference resolves a URI reference to an absolute URI from an absolute base URI, per RFC 3986 Section 5.2. The URI reference may be relative or absolute. ResolveReference always returns a new URL instance, even if the returned URL is identical to either the base or reference. If ref is an absolute URL, then ResolveReference ignores base and returns a copy of ref.


package main

import (

func main() {
	u, err := url.Parse("../../..//search?q=dotnet")
	if err != nil {
	base, err := url.Parse("http://example.com/directory/")
	if err != nil {

func (*URL) StringSource

func (u *URL) String() string

String reassembles the URL into a valid URL string. The general form of the result is one of:

scheme://[email protected]/path?query#fragment

If u.Opaque is non-empty, String uses the first form; otherwise it uses the second form. To obtain the path, String uses u.EscapedPath().

In the second form, the following rules apply:

- if u.Scheme is empty, scheme: is omitted.
- if u.User is nil, [email protected] is omitted.
- if u.Host is empty, host/ is omitted.
- if u.Scheme and u.Host are empty and u.User is nil,
   the entire scheme://[email protected]/ is omitted.
- if u.Host is non-empty and u.Path begins with a /,
   the form host/path does not add its own /.
- if u.RawQuery is empty, ?query is omitted.
- if u.Fragment is empty, #fragment is omitted.

func (*URL) UnmarshalBinarySource

func (u *URL) UnmarshalBinary(text []byte) error

type UserinfoSource

The Userinfo type is an immutable encapsulation of username and password details for a URL. An existing Userinfo value is guaranteed to have a username set (potentially empty, as allowed by RFC 2396), and optionally a password.

type Userinfo struct {
        // contains filtered or unexported fields

func UserSource

func User(username string) *Userinfo

User returns a Userinfo containing the provided username and no password set.

func UserPasswordSource

func UserPassword(username, password string) *Userinfo

UserPassword returns a Userinfo containing the provided username and password. This functionality should only be used with legacy web sites. RFC 2396 warns that interpreting Userinfo this way “is NOT RECOMMENDED, because the passing of authentication information in clear text (such as URI) has proven to be a security risk in almost every case where it has been used.”

func (*Userinfo) PasswordSource

func (u *Userinfo) Password() (string, bool)

Password returns the password in case it is set, and whether it is set.

func (*Userinfo) StringSource

func (u *Userinfo) String() string

String returns the encoded userinfo information in the standard form of "username[:password]".

func (*Userinfo) UsernameSource

func (u *Userinfo) Username() string

Username returns the username.

type ValuesSource

Values maps a string key to a list of values. It is typically used for query parameters and form values. Unlike in the http.Header map, the keys in a Values map are case-sensitive.

type Values map[string][]string


package main

import (

func main() {
	v := url.Values{}
	v.Set("name", "Ava")
	v.Add("friend", "Jess")
	v.Add("friend", "Sarah")
	v.Add("friend", "Zoe")
	// v.Encode() == "name=Ava&friend=Jess&friend=Sarah&friend=Zoe"

func ParseQuerySource

func ParseQuery(query string) (Values, error)

ParseQuery parses the URL-encoded query string and returns a map listing the values specified for each key. ParseQuery always returns a non-nil map containing all the valid query parameters found; err describes the first decoding error encountered, if any.

Query is expected to be a list of key=value settings separated by ampersands or semicolons. A setting without an equals sign is interpreted as a key set to an empty value.



m, err := url.ParseQuery(`x=1&y=2&y=3;z`)
    if err != nil {


{"x":["1"], "y":["2", "3"], "z":[""]}

func (Values) AddSource

func (v Values) Add(key, value string)

Add adds the value to key. It appends to any existing values associated with key.

func (Values) DelSource

func (v Values) Del(key string)

Del deletes the values associated with key.

func (Values) EncodeSource

func (v Values) Encode() string

Encode encodes the values into “URL encoded” form ("bar=baz&foo=quux") sorted by key.

func (Values) GetSource

func (v Values) Get(key string) string

Get gets the first value associated with the given key. If there are no values associated with the key, Get returns the empty string. To access multiple values, use the map directly.

func (Values) SetSource

func (v Values) Set(key, value string)

Set sets the key to value. It replaces any existing values.

© Google, Inc.
Licensed under the Creative Commons Attribution License 3.0.