💾 Archived View for godocs.io › net › url captured on 2024-05-26 at 14:45:35. Gemini links have been rewritten to link to archived content
⬅️ Previous capture (2024-05-12)
-=-=-=-=-=-=-
import "net/url"
Package url parses URLs and implements query escaping.
func JoinPath(base string, elem ...string) (result string, err error)
JoinPath returns a URL string with the provided path elements joined to the existing path of base and the resulting path cleaned of any ./ or ../ elements.
func PathEscape(s string) string
PathEscape escapes the string so it can be safely placed inside a URL path segment, replacing special characters (including /) with %XX sequences as needed.
Code:
package main
import (
"fmt"
"net/url"
)
func main() {
path := url.PathEscape("my/cool+blog&about,stuff")
fmt.Println(path)
}
Output:
my%2Fcool+blog&about%2Cstuff
func PathUnescape(s string) (string, error)
PathUnescape does the inverse transformation of 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 except that it does not unescape '+' to ' ' (space).
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
escapedPath := "my%2Fcool+blog&about%2Cstuff"
path, err := url.PathUnescape(escapedPath)
if err != nil {
log.Fatal(err)
}
fmt.Println(path)
}
Output:
my/cool+blog&about,stuff
func QueryEscape(s string) string
QueryEscape escapes the string so it can be safely placed inside a URL query.
Code:
package main
import (
"fmt"
"net/url"
)
func main() {
query := url.QueryEscape("my/cool+blog&about,stuff")
fmt.Println(query)
}
Output:
my%2Fcool%2Bblog%26about%2Cstuff
func QueryUnescape(s string) (string, error)
QueryUnescape does the inverse transformation of 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.
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
escapedQuery := "my%2Fcool%2Bblog%26about%2Cstuff"
query, err := url.QueryUnescape(escapedQuery)
if err != nil {
log.Fatal(err)
}
fmt.Println(query)
}
Output:
my/cool+blog&about,stuff
type Error struct {
Op string
URL string
Err error
}
Error reports an error and the operation and URL that caused it.
func (e *Error) Error() string
func (e *Error) Temporary() bool
func (e *Error) Timeout() bool
func (e *Error) Unwrap() error
type EscapeError string
func (e EscapeError) Error() string
type InvalidHostError string
func (e InvalidHostError) Error() string
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)
RawPath string // encoded path hint (see EscapedPath method)
OmitHost bool // do not emit empty host (authority)
ForceQuery bool // append a query ('?') even if RawQuery is empty
RawQuery string // encoded query values, without '?'
Fragment string // fragment for references, without '#'
RawFragment string // encoded fragment hint (see EscapedFragment method)
}
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 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, which preserves the original encoding of Path.
The RawPath field is an optional field which is only set when the default encoding of Path is different from the escaped path. See the EscapedPath method for more details.
URL's String method uses the EscapedPath method to obtain the path.
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
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:
https://google.com/search?q=golang
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
// Parse + String preserve the original encoding.
u, err := url.Parse("https://example.com/foo%2fbar")
if err != nil {
log.Fatal(err)
}
fmt.Println(u.Path)
fmt.Println(u.RawPath)
fmt.Println(u.String())
}
Output:
/foo/bar /foo%2fbar https://example.com/foo%2fbar
func Parse(rawURL string) (*URL, error)
Parse parses a raw url into a 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.
func ParseRequestURI(rawURL string) (*URL, error)
ParseRequestURI parses a raw url into a 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.)
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 uses EscapedFragment to construct its result. In general, code should call EscapedFragment instead of reading u.RawFragment directly.
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
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:
Fragment: x/y/z RawFragment: x/y%2Fz EscapedFragment: x/y%2Fz
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 and URL.RequestURI methods use EscapedPath to construct their results. In general, code should call EscapedPath instead of reading u.RawPath directly.
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
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:
Path: /x/y/z RawPath: /x/y%2Fz EscapedPath: /x/y%2Fz
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.
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
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:
example.org 2001:0db8:85a3:0000:0000:8a2e:0370:7334
func (u *URL) IsAbs() bool
IsAbs reports whether the URL is absolute. Absolute means that it has a non-empty scheme.
Code:
package main
import (
"fmt"
"net/url"
)
func main() {
u := url.URL{Host: "example.com", Path: "foo"}
fmt.Println(u.IsAbs())
u.Scheme = "http"
fmt.Println(u.IsAbs())
}
Output:
false true
func (u *URL) JoinPath(elem ...string) *URL
JoinPath returns a new 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 /.
func (u *URL) MarshalBinary() (text []byte, err error)
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
u, _ := url.Parse("https://example.org")
b, err := u.MarshalBinary()
if err != nil {
log.Fatal(err)
}
fmt.Printf("%s\n", b)
}
Output:
https://example.org
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 URL.ResolveReference.
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
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:
https://example.org/foo
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.
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
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:
8080
func (u *URL) Query() Values
Query parses RawQuery and returns the corresponding values. It silently discards malformed value pairs. To check errors use ParseQuery.
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
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:
[1 2] 3
func (u *URL) Redacted() string
Redacted is like URL.String but replaces any password with "xxxxx". Only the password in u.User is redacted.
Code:
package main
import (
"fmt"
"net/url"
)
func main() {
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:
https://user:xxxxx@example.com/foo/bar https://me:xxxxx@example.com/foo/bar
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.
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
u, err := url.Parse("https://example.org/path?foo=bar")
if err != nil {
log.Fatal(err)
}
fmt.Println(u.RequestURI())
}
Output:
/path?foo=bar
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 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.
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
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:
http://example.com/search?q=dotnet
func (u *URL) String() string
String reassembles the 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:
Code:
package main
import (
"fmt"
"net/url"
)
func main() {
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:
https://me:pass@example.com/foo/bar?x=1&y=2#anchor https:opaque?x=1&y=2#anchor
func (u *URL) UnmarshalBinary(text []byte) error
Code:
package main
import (
"fmt"
"log"
"net/url"
)
func main() {
u := &url.URL{}
err := u.UnmarshalBinary([]byte("https://example.org/foo"))
if err != nil {
log.Fatal(err)
}
fmt.Printf("%s\n", u)
}
Output:
https://example.org/foo
type Userinfo struct {
// contains filtered or unexported fields
}
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.
func User(username string) *Userinfo
User returns a Userinfo containing the provided username and no password set.
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 (u *Userinfo) Password() (string, bool)
Password returns the password in case it is set, and whether it is set.
func (u *Userinfo) String() string
String returns the encoded userinfo information in the standard form of "username[:password]".
func (u *Userinfo) Username() string
Username returns the username.
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.
Code:
package main
import (
"fmt"
"net/url"
)
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"
fmt.Println(v.Get("name"))
fmt.Println(v.Get("friend"))
fmt.Println(v["friend"])
}
Output:
Ava Jess [Jess Sarah Zoe]
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.
Code:
package main
import (
"encoding/json"
"fmt"
"log"
"net/url"
"strings"
)
func main() {
m, err := url.ParseQuery(`x=1&y=2&y=3`)
if err != nil {
log.Fatal(err)
}
fmt.Println(toJSON(m))
}
func toJSON(m any) string {
js, err := json.Marshal(m)
if err != nil {
log.Fatal(err)
}
return strings.ReplaceAll(string(js), ",", ", ")
}
Output:
{"x":["1"], "y":["2", "3"]}
func (v Values) Add(key, value string)
Add adds the value to key. It appends to any existing values associated with key.
Code:
package main
import (
"fmt"
"net/url"
)
func main() {
v := url.Values{}
v.Add("cat sounds", "meow")
v.Add("cat sounds", "mew")
v.Add("cat sounds", "mau")
fmt.Println(v["cat sounds"])
}
Output:
[meow mew mau]
func (v Values) Del(key string)
Del deletes the values associated with key.
Code:
package main
import (
"fmt"
"net/url"
)
func main() {
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:
[meow mew mau] []
func (v Values) Encode() string
Encode encodes the values into “URL encoded” form ("bar=baz&foo=quux") sorted by key.
Code:
package main
import (
"fmt"
"net/url"
)
func main() {
v := url.Values{}
v.Add("cat sounds", "meow")
v.Add("cat sounds", "mew/")
v.Add("cat sounds", "mau$")
fmt.Println(v.Encode())
}
Output:
cat+sounds=meow&cat+sounds=mew%2F&cat+sounds=mau%24
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.
Code:
package main
import (
"fmt"
"net/url"
)
func main() {
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:
"meow" ""
func (v Values) Has(key string) bool
Has checks whether a given key is set.
Code:
package main
import (
"fmt"
"net/url"
)
func main() {
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:
true false
func (v Values) Set(key, value string)
Set sets the key to value. It replaces any existing values.
Code:
package main
import (
"fmt"
"net/url"
)
func main() {
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:
[meow mew mau] [meow]