shorteners

Documentation

Overview

Package shorteners provides utilities for retrieving information about URL shortening websites.

Index

• Variables
• type CleanFunc
• type IsVanityFunc
• type Shortener
  • func (s *Shortener) Clean(shortURL string) (string, error)
  • func (s *Shortener) CleanURL(u *url.URL) (string, error)
  • func (s *Shortener) CleanURLs(urls []string) ([]string, error)
  • func (s *Shortener) GetIAShortcodes() ([]string, error)
  • func (s *Shortener) IsVanity(shortcode string) bool
  • func (s *Shortener) Sort(shortcodes []string)

Variables

var Allst = &Shortener{
	Name:     "a-ll-st",
	Host:     "a.ll.st",
	Prefix:   "http://a.ll.st/",
	Alphabet: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",

	Pattern: regexp.MustCompile(`^[0-9A-Za-z_]+$`),
	CleanFunc: func(shortcode string, u *url.URL) string {
		if strings.HasPrefix(shortcode, "scmf/") {
			shortcode = shortcode[strings.LastIndexByte(shortcode, '/')+1:]
		}
		return shortcode
	},
	IsVanityFunc: func(shortcode string) bool {
		return len(shortcode) != 6 || strings.ContainsRune(shortcode, '_')
	},
	HasVanity: true,
}

Allst describes the Allstate a.ll.st link shortener.

var Bfytw = &Shortener{
	Name:     "bfy-tw",
	Host:     "bfy.tw",
	Prefix:   "https://bfy.tw/",
	Alphabet: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",
	Pattern:  regexp.MustCompile(`^[0-9A-Za-z]+$`),
	CleanFunc: func(shortcode string, u *url.URL) string {
		return bfytwTrailing.ReplaceAllLiteralString(shortcode, "")
	},
	HasVanity: false,
}

Bfytw describes the bfy.tw link shortener. All URLs redirect to https://lmgtfy.app/?q=<query>

var Debli = &Shortener{
	Name:     "deb-li",
	Host:     "deb.li",
	Prefix:   "https://deb.li/",
	Alphabet: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",
	Pattern:  regexp.MustCompile(`^[0-9A-Za-z]+$`),
	CleanFunc: func(shortcode string, u *url.URL) string {

		if strings.ContainsRune(shortcode, '@') {
			return ""
		}

		shortcode = strings.TrimPrefix(shortcode, "p/")

		if strings.ContainsRune(shortcode, '/') || strings.ContainsRune(shortcode, '.') {
			return ""
		}
		return shortcode
	},
	HasVanity: true,
}

Debli describes the Debian deb.li link shortener.

var GoHawaiiEdu = &Shortener{
	Name:     "go-hawaii-edu",
	Host:     "go.hawaii.edu",
	Prefix:   "https://go.hawaii.edu/",
	Alphabet: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",
	Pattern:  regexp.MustCompile(`^[0-9A-Za-z]+$`),
	CleanFunc: func(shortcode string, u *url.URL) string {
		if strings.ContainsRune(shortcode, '/') {
			return ""
		}
		switch shortcode {
		case "admin", "submit":
			return ""
		}

		return strings.TrimSuffix(shortcode, "+")
	},
	HasVanity: false,
}

GoHawaiiEdu describes the University of Hawaii go.hawaii.edu link shortener.

var Lookup = make(map[string]*Shortener)

var MobyTo = &Shortener{
	Name:     "moby-to",
	Host:     "moby.to",
	Prefix:   "http://moby.to/",
	Alphabet: "0123456789abcdefghijklmnopqrstuvwxyz",
	Pattern:  regexp.MustCompile("^[0-9a-z]+$"),
	CleanFunc: func(shortcode string, u *url.URL) string {
		if strings.ContainsRune(shortcode, '/') {
			return ""
		}

		if i := strings.IndexAny(shortcode, ":-+*."); i != -1 {
			shortcode = shortcode[:i]
		}
		return strings.ToLower(shortcode)
	},
	HasVanity: false,
}

MobyTo describes the Mobypicture moby.to link shortener.

var Qrcx = &Shortener{
	Name:      "qr-cx",
	Host:      "qr.cx",
	Prefix:    "http://qr.cx/",
	Alphabet:  "123456789ABCDEFGHJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",
	Pattern:   regexp.MustCompile(`^[1-9A-HJ-Za-z]+$`),
	CleanFunc: cleanQrcx,
	HasVanity: false,
}

Qrcx describes the qr.cx link shortener.

var Rbgy = &Shortener{
	Name:     "rb-gy",
	Host:     "rb.gy",
	Prefix:   "https://rb.gy/",
	Alphabet: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",
	Pattern:  regexp.MustCompile(`^[0-9A-Za-z]+$`),
	CleanFunc: func(shortcode string, u *url.URL) string {

		shortcode = trimAfterAny(shortcode, "+/._-:$@◄")

		shortcode = rbgyNonAlpha.ReplaceAllLiteralString(shortcode, "")

		if len(shortcode) > 6 {
			shortcode = shortcode[:6]
		}
		return strings.ToLower(shortcode)
	},
	HasVanity: false,
}

Rbgy describes the rb-gy link shortener, which is powered by Rebrandly.

var RedHt = &Shortener{
	Name:     "red-ht",
	Host:     "red.ht",
	Prefix:   "https://red.ht/",
	Alphabet: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",

	Pattern: regexp.MustCompile(`^[0-9A-Za-z\-_]+$`),
	CleanFunc: func(shortcode string, u *url.URL) string {

		if strings.ContainsRune(shortcode, '.') {
			return ""
		}

		return trimAfterByte(shortcode, '@')
	},
	IsVanityFunc: func(shortcode string) bool {
		return strings.ContainsAny(shortcode, "-_")
	},
	HasVanity: true,
}

RedHt describes the Red Hat red.ht link shortener.

var SUconnEdu = &Shortener{
	Name:     "s-uconn-edu",
	Host:     "s.uconn.edu",
	Prefix:   "https://s.uconn.edu/",
	Alphabet: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",
	Pattern:  regexp.MustCompile(`^[0-9A-Za-z\-_]+$`),
	CleanFunc: func(shortcode string, u *url.URL) string {

		if strings.ContainsRune(shortcode, '/') {
			return ""
		}

		return strings.ToLower(shortcode)
	},
	IsVanityFunc: func(shortcode string) bool {
		return strings.ContainsRune(shortcode, '-')
	},
	HasVanity: true,
}

SUconnEdu describes the University of Connecticut s.uconn.edu link shortener.

var ShortIm = &Shortener{
	Name:     "short-im",
	Host:     "short.im",
	Prefix:   "http://short.im/",
	Alphabet: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",

	Pattern:   regexp.MustCompile(`^[0-9A-Za-z\-_]+$`),
	CleanFunc: cleanShortIm,
	HasVanity: true,
}

ShortIm describes the Short.i'm short.im link shortener.

var Shorteners = []*Shortener{
	Allst,
	Bfytw,
	Debli,
	GoHawaiiEdu,
	MobyTo,
	Qrcx,
	Rbgy,
	RedHt,
	ShortIm,
	SUconnEdu,
}

Types

type CleanFunc

type CleanFunc func(shortcode string, u *url.URL) string

type IsVanityFunc

type IsVanityFunc func(shortcode string) bool

type Shortener

type Shortener struct {
	Name         string
	Host         string
	Prefix       string
	Alphabet     string
	Pattern      *regexp.Regexp
	CleanFunc    CleanFunc
	IsVanityFunc IsVanityFunc
	HasVanity    bool
}

func (*Shortener) Clean

func (s *Shortener) Clean(shortURL string) (string, error)

Clean extracts the shortcode from a URL. An empty string is returned when no shortcode can be found.

func (*Shortener) CleanURL

func (s *Shortener) CleanURL(u *url.URL) (string, error)

CleanURL extracts the shortcode from a URL. An empty string is returned when no shortcode can be found.

func (*Shortener) CleanURLs

func (s *Shortener) CleanURLs(urls []string) ([]string, error)

CleanURLs extracts, deduplicates, and sorts the shortcodes in slice of URLs.

func (*Shortener) GetIAShortcodes

func (s *Shortener) GetIAShortcodes() ([]string, error)

GetIAShortcodes queries all the shortcodes that have been archived on the Internet Archive.

func (*Shortener) IsVanity

func (s *Shortener) IsVanity(shortcode string) bool

IsVanity returns true when a shortcode is a vanity code. There are many false negatives for vanity codes that are programmatically indistinguishable from generated codes.

func (*Shortener) Sort

func (s *Shortener) Sort(shortcodes []string)

Sort sorts shorter codes first and generated codes before vanity codes.