# net/url

Package url parses URLs and implements query escaping.

See RFC 3986. This package generally follows RFC 3986, except where it deviates for compatibility reasons. RFC 6874 followed for IPv6 zone literals.

## JoinPath

```go
func JoinPath(base string, elem ...string) (result string, err error)
```

JoinPath returns a [URL](#type-URL) string with the provided path elements joined to the existing path of base and the resulting path cleaned of any ./ or ../ elements. Path elements must already be in escaped form, as produced by [PathEscape](#func-PathEscape).

## Parse

```go
func Parse(rawURL string) (*URL, error)
```

Parse parses a raw url into a [URL](#type-URL) structure.

The url may be relative (a path, without a host) or absolute (starting with a scheme). Trying to parse a hostname and path without a scheme is invalid but may not necessarily return an error, due to parsing ambiguities.

## ParseQuery

```go
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. A setting without an equals sign is interpreted as a key set to an empty value. Settings containing a non-URL-encoded semicolon are considered invalid.

### Example: ParseQuery

```go
{
	m, err := url.ParseQuery(`x=1&y=2&y=3`)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(toJSON(m))

}
```

Output:

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

## ParseRequestURI

```go
func ParseRequestURI(rawURL string) (*URL, error)
```

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

## PathEscape

```go
func PathEscape(s string) string
```

PathEscape escapes the string so it can be safely placed inside a [URL](#type-URL) path segment, replacing special characters (including /) with %XX sequences as needed.

### Example: PathEscape

```go
{
	path := url.PathEscape("my/cool+blog&about,stuff")
	fmt.Println(path)

}
```

Output:

```text
my%2Fcool+blog&about%2Cstuff
```

## PathUnescape

```go
func PathUnescape(s string) (string, error)
```

PathUnescape does the inverse transformation of [PathEscape](#func-PathEscape), converting each 3-byte encoded substring of the form "%AB" into the hex-decoded byte 0xAB. It returns an error if any % is not followed by two hexadecimal digits.

PathUnescape is identical to [QueryUnescape](#func-QueryUnescape) except that it does not unescape '+' to ' ' (space).

### Example: PathUnescape

```go
{
	escapedPath := "my%2Fcool+blog&about%2Cstuff"
	path, err := url.PathUnescape(escapedPath)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(path)

}
```

Output:

```text
my/cool+blog&about,stuff
```

## QueryEscape

```go
func QueryEscape(s string) string
```

QueryEscape escapes the string so it can be safely placed inside a [URL](#type-URL) query.

### Example: QueryEscape

```go
{
	query := url.QueryEscape("my/cool+blog&about,stuff")
	fmt.Println(query)

}
```

Output:

```text
my%2Fcool%2Bblog%26about%2Cstuff
```

## QueryUnescape

```go
func QueryUnescape(s string) (string, error)
```

QueryUnescape does the inverse transformation of [QueryEscape](#func-QueryEscape), converting each 3-byte encoded substring of the form "%AB" into the hex-decoded byte 0xAB. It returns an error if any % is not followed by two hexadecimal digits.

### Example: QueryUnescape

```go
{
	escapedQuery := "my%2Fcool%2Bblog%26about%2Cstuff"
	query, err := url.QueryUnescape(escapedQuery)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(query)

}
```

Output:

```text
my/cool+blog&about,stuff
```

## User

```go
func User(username string) *Userinfo
```

User returns a [Userinfo](#type-Userinfo) containing the provided username and no password set.

## UserPassword

```go
func UserPassword(username, password string) *Userinfo
```

UserPassword returns a [Userinfo](#type-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.”

## Error

```go
type Error struct {
	Op  string
	URL string
	Err error
}
```

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

- `Op: string`: 
- `URL: string`: 
- `Err: error`: 

## Error

```go
func (e *Error) Error() string
```

## Temporary

```go
func (e *Error) Temporary() bool
```

## Timeout

```go
func (e *Error) Timeout() bool
```

## Unwrap

```go
func (e *Error) Unwrap() error
```

## EscapeError

```go
type EscapeError string
```

## Error

```go
func (e EscapeError) Error() string
```

## InvalidHostError

```go
type InvalidHostError string
```

## Error

```go
func (e InvalidHostError) Error() string
```

## URL

```go
type URL struct {
	Scheme   string
	Opaque   string    // encoded opaque data
	User     *Userinfo // username and password information
	Host     string    // "host" or "host:port" (see Hostname and Port methods)
	Path     string    // path (relative paths may omit leading slash)
	Fragment string    // fragment for references (without '#')

	// RawQuery contains the encoded query values, without the initial '?'.
	// Use URL.Query to decode the query.
	RawQuery string

	// RawPath is an optional field containing an encoded path hint.
	// See the EscapedPath method for more details.
	//
	// In general, code should call EscapedPath instead of reading RawPath.
	RawPath string

	// RawFragment is an optional field containing an encoded fragment hint.
	// See the EscapedFragment method for more details.
	//
	// In general, code should call EscapedFragment instead of reading RawFragment.
	RawFragment string

	// ForceQuery indicates whether the original URL contained a query ('?') character.
	// When set, the String method will include a trailing '?', even when RawQuery is empty.
	ForceQuery bool

	// OmitHost indicates the URL has an empty host (authority).
	// When set, the String method will not include the host when it is empty.
	OmitHost bool
}
```

A URL represents a parsed URL (technically, a URI reference).

The general form represented is:

	[scheme:][//[userinfo@]host][/]path[?query][#fragment]

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

	scheme:opaque[?query][#fragment]

The Host field contains the host and port subcomponents of the URL. When the port is present, it is separated from the host with a colon. When the host is an IPv6 address, it must be enclosed in square brackets: "\[fe80::1]:80". The [net.JoinHostPort](https://pkg.go.dev/net#JoinHostPort) function combines a host and port into a string suitable for the Host field, adding square brackets to the host when necessary.

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, the code should use the [URL.EscapedPath](#method-URL-EscapedPath) method, which preserves the original encoding of Path. The Fragment field is also stored in decoded form, use [URL.EscapedFragment](#method-URL-EscapedFragment) to retrieve the original encoding.

The [URL.String](#method-URL-String) method uses the [URL.EscapedPath](#method-URL-EscapedPath) method to obtain the path.

- `Scheme: string`: 
- `Opaque: string`: encoded opaque data
- `User: *Userinfo`: username and password information
- `Host: string`: "host" or "host:port" (see Hostname and Port methods)
- `Path: string`: path (relative paths may omit leading slash)
- `Fragment: string`: fragment for references (without '#')
- `RawQuery: string`: RawQuery contains the encoded query values, without the initial '?'. Use URL.Query to decode the query.
- `RawPath: string`: RawPath is an optional field containing an encoded path hint. See the EscapedPath method for more details.

In general, code should call EscapedPath instead of reading RawPath.
- `RawFragment: string`: RawFragment is an optional field containing an encoded fragment hint. See the EscapedFragment method for more details.

In general, code should call EscapedFragment instead of reading RawFragment.
- `ForceQuery: bool`: ForceQuery indicates whether the original URL contained a query ('?') character. When set, the String method will include a trailing '?', even when RawQuery is empty.
- `OmitHost: bool`: OmitHost indicates the URL has an empty host (authority). When set, the String method will not include the host when it is empty.

## AppendBinary

```go
func (u *URL) AppendBinary(b []byte) ([]byte, error)
```

## EscapedFragment

```go
func (u *URL) EscapedFragment() string
```

EscapedFragment returns the escaped form of u.Fragment. In general there are multiple possible escaped forms of any fragment. EscapedFragment returns u.RawFragment when it is a valid escaping of u.Fragment. Otherwise EscapedFragment ignores u.RawFragment and computes an escaped form on its own. The [URL.String](#method-URL-String) method uses EscapedFragment to construct its result. In general, code should call EscapedFragment instead of reading u.RawFragment directly.

### Example: URL_EscapedFragment

```go
{
	u, err := url.Parse("http://example.com/#x/y%2Fz")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println("Fragment:", u.Fragment)
	fmt.Println("RawFragment:", u.RawFragment)
	fmt.Println("EscapedFragment:", u.EscapedFragment())

}
```

Output:

```text
Fragment: x/y/z
RawFragment: x/y%2Fz
EscapedFragment: x/y%2Fz
```

## EscapedPath

```go
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 [URL.String](#method-URL-String) and [URL.RequestURI](#method-URL-RequestURI) methods use EscapedPath to construct their results. In general, code should call EscapedPath instead of reading u.RawPath directly.

### Example: URL_EscapedPath

```go
{
	u, err := url.Parse("http://example.com/x/y%2Fz")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println("Path:", u.Path)
	fmt.Println("RawPath:", u.RawPath)
	fmt.Println("EscapedPath:", u.EscapedPath())

}
```

Output:

```text
Path: /x/y/z
RawPath: /x/y%2Fz
EscapedPath: /x/y%2Fz
```

## Hostname

```go
func (u *URL) Hostname() string
```

Hostname returns u.Host, stripping any valid port number if present.

If the result is enclosed in square brackets, as literal IPv6 addresses are, the square brackets are removed from the result.

### Example: URL_Hostname

```go
{
	u, err := url.Parse("https://example.org:8000/path")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(u.Hostname())
	u, err = url.Parse("https://[2001:0db8:85a3:0000:0000:8a2e:0370:7334]:17000")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(u.Hostname())

}
```

Output:

```text
example.org
2001:0db8:85a3:0000:0000:8a2e:0370:7334
```

## IsAbs

```go
func (u *URL) IsAbs() bool
```

IsAbs reports whether the [URL](#type-URL) is absolute. Absolute means that it has a non-empty scheme.

### Example: URL_IsAbs

```go
{
	u := url.URL{Host: "example.com", Path: "foo"}
	fmt.Println(u.IsAbs())
	u.Scheme = "http"
	fmt.Println(u.IsAbs())

}
```

Output:

```text
false
true
```

## JoinPath

```go
func (u *URL) JoinPath(elem ...string) *URL
```

JoinPath returns a new [URL](#type-URL) with the provided path elements joined to any existing path and the resulting path cleaned of any ./ or ../ elements. Any sequences of multiple / characters will be reduced to a single /. Path elements must already be in escaped form, as produced by [PathEscape](#func-PathEscape).

### Example: URL_JoinPath

```go
{
	u, err := url.Parse("https://example.com/foo/bar")
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println(u.JoinPath("baz", "qux"))

}
```

Output:

```text
https://example.com/foo/bar/baz/qux
```

## MarshalBinary

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

### Example: URL_MarshalBinary

```go
{
	u, _ := url.Parse("https://example.org")
	b, err := u.MarshalBinary()
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%s\n", b)

}
```

Output:

```text
https://example.org
```

## Parse

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

Parse parses a [URL](#type-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 [URL.ResolveReference](#method-URL-ResolveReference).

### Example: URL_Parse

```go
{
	u, err := url.Parse("https://example.org")
	if err != nil {
		log.Fatal(err)
	}
	rel, err := u.Parse("/foo")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(rel)
	_, err = u.Parse(":foo")
	if _, ok := err.(*url.Error); !ok {
		log.Fatal(err)
	}

}
```

Output:

```text
https://example.org/foo
```

## Port

```go
func (u *URL) Port() string
```

Port returns the port part of u.Host, without the leading colon.

If u.Host doesn't contain a valid numeric port, Port returns an empty string.

### Example: URL_Port

```go
{
	u, err := url.Parse("https://example.org")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(u.Port())
	u, err = url.Parse("https://example.org:8080")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(u.Port())

}
```

Output:

```text
8080
```

## Query

```go
func (u *URL) Query() Values
```

Query parses RawQuery and returns the corresponding values. It silently discards malformed value pairs. To check errors use [ParseQuery](#func-ParseQuery).

### Example: URL_Query

```go
{
	u, err := url.Parse("https://example.org/?a=1&a=2&b=&=3&&&&")
	if err != nil {
		log.Fatal(err)
	}
	q := u.Query()
	fmt.Println(q["a"])
	fmt.Println(q.Get("b"))
	fmt.Println(q.Get(""))

}
```

Output:

```text
[1 2]

3
```

## Redacted

```go
func (u *URL) Redacted() string
```

Redacted is like [URL.String](#method-URL-String) but replaces any password with "xxxxx". Only the password in u.User is redacted.

### Example: URL_Redacted

```go
{
	u := &url.URL{
		Scheme: "https",
		User:   url.UserPassword("user", "password"),
		Host:   "example.com",
		Path:   "foo/bar",
	}
	fmt.Println(u.Redacted())
	u.User = url.UserPassword("me", "newerPassword")
	fmt.Println(u.Redacted())

}
```

Output:

```text
https://user:xxxxx@example.com/foo/bar
https://me:xxxxx@example.com/foo/bar
```

## RequestURI

```go
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.

### Example: URL_RequestURI

```go
{
	u, err := url.Parse("https://example.org/path?foo=bar")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(u.RequestURI())

}
```

Output:

```text
/path?foo=bar
```

## ResolveReference

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

ResolveReference resolves a URI reference to an absolute URI from an absolute base URI u, per RFC 3986 Section 5.2. The URI reference may be relative or absolute. ResolveReference always returns a new [URL](#type-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.

### Example: URL_ResolveReference

```go
{
	u, err := url.Parse("../../..//search?q=dotnet")
	if err != nil {
		log.Fatal(err)
	}
	base, err := url.Parse("http://example.com/directory/")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(base.ResolveReference(u))

}
```

Output:

```text
http://example.com/search?q=dotnet
```

## String

```go
func (u *URL) String() string
```

String reassembles the [URL](#type-URL) into a valid URL string. The general form of the result is one of:

	scheme:opaque?query#fragment
	scheme://userinfo@host/path?query#fragment

If u.Opaque is non-empty, String uses the first form; otherwise it uses the second form. Any non-ASCII characters in host are escaped. 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, userinfo@ 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://userinfo@host/ 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.

### Example: URL_String

```go
{
	u := &url.URL{
		Scheme:   "https",
		User:     url.UserPassword("me", "pass"),
		Host:     "example.com",
		Path:     "foo/bar",
		RawQuery: "x=1&y=2",
		Fragment: "anchor",
	}
	fmt.Println(u.String())
	u.Opaque = "opaque"
	fmt.Println(u.String())

}
```

Output:

```text
https://me:pass@example.com/foo/bar?x=1&y=2#anchor
https:opaque?x=1&y=2#anchor
```

## UnmarshalBinary

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

### Example: URL_UnmarshalBinary

```go
{
	u := &url.URL{}
	err := u.UnmarshalBinary([]byte("https://example.org/foo"))
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%s\n", u)

}
```

Output:

```text
https://example.org/foo
```

### Example: URL

```go
{
	u, err := url.Parse("http://bing.com/search?q=dotnet")
	if err != nil {
		log.Fatal(err)
	}
	u.Scheme = "https"
	u.Host = "google.com"
	q := u.Query()
	q.Set("q", "golang")
	u.RawQuery = q.Encode()
	fmt.Println(u)

}
```

Output:

```text
https://google.com/search?q=golang
```

## Userinfo

```go
type Userinfo struct {
	// contains filtered or unexported fields
}
```

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

## Password

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

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

## String

```go
func (u *Userinfo) String() string
```

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

## Username

```go
func (u *Userinfo) Username() string
```

Username returns the username.

## Values

```go
type Values map[string][]string
```

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.

## Add

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

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

### Example: Values_Add

```go
{
	v := url.Values{}
	v.Add("cat sounds", "meow")
	v.Add("cat sounds", "mew")
	v.Add("cat sounds", "mau")
	fmt.Println(v["cat sounds"])

}
```

Output:

```text
[meow mew mau]
```

## Del

```go
func (v Values) Del(key string)
```

Del deletes the values associated with key.

### Example: Values_Del

```go
{
	v := url.Values{}
	v.Add("cat sounds", "meow")
	v.Add("cat sounds", "mew")
	v.Add("cat sounds", "mau")
	fmt.Println(v["cat sounds"])

	v.Del("cat sounds")
	fmt.Println(v["cat sounds"])

}
```

Output:

```text
[meow mew mau]
[]
```

## Encode

```go
func (v Values) Encode() string
```

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

### Example: Values_Encode

```go
{
	v := url.Values{}
	v.Add("cat sounds", "meow")
	v.Add("cat sounds", "mew/")
	v.Add("cat sounds", "mau$")
	fmt.Println(v.Encode())

}
```

Output:

```text
cat+sounds=meow&cat+sounds=mew%2F&cat+sounds=mau%24
```

## Get

```go
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.

### Example: Values_Get

```go
{
	v := url.Values{}
	v.Add("cat sounds", "meow")
	v.Add("cat sounds", "mew")
	v.Add("cat sounds", "mau")
	fmt.Printf("%q\n", v.Get("cat sounds"))
	fmt.Printf("%q\n", v.Get("dog sounds"))

}
```

Output:

```text
"meow"
""
```

## Has

```go
func (v Values) Has(key string) bool
```

Has checks whether a given key is set.

### Example: Values_Has

```go
{
	v := url.Values{}
	v.Add("cat sounds", "meow")
	v.Add("cat sounds", "mew")
	v.Add("cat sounds", "mau")
	fmt.Println(v.Has("cat sounds"))
	fmt.Println(v.Has("dog sounds"))

}
```

Output:

```text
true
false
```

## Set

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

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

### Example: Values_Set

```go
{
	v := url.Values{}
	v.Add("cat sounds", "meow")
	v.Add("cat sounds", "mew")
	v.Add("cat sounds", "mau")
	fmt.Println(v["cat sounds"])

	v.Set("cat sounds", "meow")
	fmt.Println(v["cat sounds"])

}
```

Output:

```text
[meow mew mau]
[meow]
```

### Example: Values

```go
{
	v := url.Values{}
	v.Set("name", "Ava")
	v.Add("friend", "Jess")
	v.Add("friend", "Sarah")
	v.Add("friend", "Zoe")
	fmt.Println(v.Encode())
	fmt.Println(v.Get("name"))
	fmt.Println(v.Get("friend"))
	fmt.Println(v["friend"])

}
```

Output:

```text
friend=Jess&friend=Sarah&friend=Zoe&name=Ava
Ava
Jess
[Jess Sarah Zoe]
```