geongeorge/i-hate-regex

The code for iHateregex.io 😈 - The Regex Cheat Sheet

iHateRegex 😈

don't just use; understand.

iHateRegex.io - a regex cheatsheet for the haters.

Chat with us on Telegram

Features 😎

• Visual representation of regular expressions
• Matched strings - the Testing area
• Embed regular expression visualization on your sites
• Regex code highlighting and validation
• Regex description with markdown support
• Playground page where you can create your own expression and link to it.
• User login and save regex

Setup 🚀

1. Install yarn

2. Clone this repo

3. Install dependencies ⚙️

$ yarn install

4. Test on localhost 🛠

# serve with hot reload at localhost:3600
$ yarn dev

5. Build and Start nuxt server 🚀

# build for production and launch server
$ yarn build
$ yarn start

This project is built with Nuxt.js 🙌

For detailed explanation on how things work, check out Nuxt.js docs.

Contribute Regex 🙏

Contribute to this project and make this the largest collection of useful expressions 😍

You can also submit regex via this google form

To contribute:

1. Add your regex to /static/regex/data.json

Show sample JSON

{
        "id": "username",
        "title": "username",
        "tagline": "match a username",
        "description": "Alphanumeric string that may include _ and - having a length of 3 to 16 characters.",
        "regex": "^[a-z0-9_-]{3,15}$",
        "flag": "gm",
        "matchText": [
            "lorem",
            "ipsum",
            "gr3at",
            "a",
            "ab",
            "abcd",
            "abcde",
            "john doe",
            "johnny",
            "abcdefghijklmnopqrst"
        ],
        "cheatRegex": [
            "/^/",
            "/$/",
            "/[a-zA-Z0-9]/",
            "/(hello){1,3}/"
        ],
        "embedHeight": 300,
        "tags" : ["name", "slug"]
    },

Show JSON properties

Property	Definition
id	this is the slug and also the short name of the regex. cannot contain spaces and only contain url-safe characters
title	Title of the page.
tagline	Tagline
description	First line under the tagline and also the meta description
regex	The actual regex string
flag	regex flags associated with the expression. eg; g
matchText	Array(line by line) of strings to be included in the string matching are
cheatRegex	refer static/regex/cheatsheet.json and see what all cheats are relevent to this expression. (you can also add your own cheats into cheatsheet.json and refer to that)
embedHeight	Height in pixels of the regex visualization embed
tags	tags related to the expression (to be used later)

2. Create a markdown file in /static/regex/markdown/ named <regex-id>.md for longer description and explanation

   <regex-id> is the id from data.json

That's it 🙌 Go ahead and shoot a new pull request✨✨

Descriptions

There are 2 descriptions for each regex.

• One is the description property inside /static/regex/data.json.

  • This is used for page meta description as well.
  • This is the first description

• Second is a dedicated markdown file in /static/regex/markdown/<file>.md

  • This should explain how the expression works in detail.
  • This is the long description
  

Property	Definition	example
description property inside data.json	This should explain about what the target match is in a few lines. It should not contain any html or markdown	A username is a unique identifier given to accounts in websites and social media
dedicated markdown file	Explain about the expression and how it works	ip addresses are of the range 0.0.0.0 - 255.255.255.255. The expression matches the ....(more)

Sponsors 💖

Donate via Opencollective

Credits

• The visual demo is built with: regexper

i-hate-regex's Issues

page crashes the browser

for some reason my browsers crash every time I access this link https://ihateregex.io/expr/url

somebody else?

details:

• ubuntu 18.04
• firefox 75.0
• chromium 80.0

Embed code

Hello,
I'm working on this repository for adding some regex which I thought may be useful. I followed all the mentioned steps. However I'm not getting proper embed turing machine flow.
For my regex it is showing invalid embed image. You can see it here.
Is there anything I'm doing wrong?
Thank you

Question about "lookahead" and "reflash".

I find two small questions about this. As follows:

1. About "lookahead", I find it can't lookahead forward. For example,
   | play around with regex | matches | expect output | real output |
   | ---------------------- | ---- | ---- | ---- |
   | (?<=num)\d+ | num123 | 123 | Error: Line 1: expected "?"(?<=num)\d+|
2. When I input regex, it will reflash. But it will set the pointer to the start which makes trouble to input new word and then throws error.

Nonetheless, I absolutely love this util. It offers many samples and can display how the regex matching. Thank you for create this!
XD.

Markdown for "firstdescr"

I believe that we need to reference some resources or RFCs in some regex descriptions, is it possible to support markdown at least only for this field?

ipv4 false positive with 1.1.1.00

Regex for email complicated does not handle curly quotes

The regex (([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,})) won't handle emails like

• “[email protected]” (curly quote)
• '[email protected]'

I propose changing it to (([^<>()\[\]\\.,;:\s@"“”‘’]+(\.[^<>()\[\]\\.,;:\s@"“”‘’]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))

See here for examples

Horizontal Scrollbar on Graph

Its really hard to navigate horizontally when the regex graph is really big. One have to scroll down to be able to use horizontal scroll.

https://ihateregex.io/expr/ipv6

regex for ip address(ipv6) error

Cannot match ipv6 address correctly

Add user login

Implement user login and allow users to create their own regex pastes
similar to codepen and jsfiddle

Fix regular expressions that are vulnerable to ReDoS

https://en.wikipedia.org/wiki/ReDoS
https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS

CPF(Brazilian document) regex not found

CPF regex not found

Question: Regular Expression "Flavor"

Regular Expression engines differ from one language to another:
https://en.wikipedia.org/wiki/Comparison_of_regular-expression_engines

What would it mean to allow plugging-in different engine, as in: https://regex101.com/
Is there any work being done on that front ?

Parsing escaped regexes

This is absolutely brilliant!

It would be lovely if I could paste (or type) in a regex that has been written with escapes (e.g. as per a shell script) and for the parser to understand the escapes. As an example...

\(x86\(_64\)\?\|arm\(hf\|v7\)\)\

is the escaped version of

(x86(_64)?|arm(hf|v7))

and to be able to escape or un-escape an expression. That would be fantastic.

Really good tool, just a suggestion. Many thanks for providing 🥇

[Regex Request] ISO 8601

Request for ISO 8601 (date & time format) Regex.

Is there a bug in the online CheatSheet?

Hello I.H.R. DreamTeam,

First congrats for this useful tool, and thanks for your work.

This cheat sheet ( https://ihateregex.io/cheatsheet ) says :
/h.llo/ the '.' matches any one character other than a new line character... matches 'hello', 'hallo' but not 'h llo'

I am afraid I disagree : The last target "h" SPACE "llo" is matched by "/h.llo/", don't you think?
You may have wanted to write "hllo", isn't it?

KUTGW & best regards.

Image match regex

A simple image regex, something like /.*\.(gif|jpe?g|bmp|png)$/igm 😄

[Regex issue] URL regex doesn't match all domains

Maximum of 6 characters for TLD is not enough. There are TLDs like .accountants. Currently the longest TLD is 24 characters long, and the limit is 63 characters. So... We have to do something with it. Manually update the length (though it isn't going to change often) or just use 63 characters.

Error when using lookbehind

The matches are correct, but the svg won't render

Use I hate regex to document code

I hate regex too and would rather not use it but my coworker do and it makes code review very hard.

I wonder if there could be a simple way to use your awesome service to improve code review.

My first idea was to document code with a link to your service identifying uniquely the regex in the code.

What do you think about it?

Cant catch a single word line.

I tried ^foo$
but it wont work.
foo$ works
and ^foo

the 'date' regex gets leap year wrong

Hello,

https://ihateregex.io/expr/date/

The date regex gets leap years wrong. Leap years divisible by 400 should not match.
The regex successfully matches Feb 29, 2000. It should not.

BTW, other than leap year it is an amazing regex, thank you.

State the engine / flavour

I really like the design of your website.
But it nowhere mentions the used engine/flavour (Python2, Python3, JavaScript, ...). There are differences you might know.

Aren't the `\b` in the UUID regex superfluous?

I'm not convinced the \b in the UUID regex serve any purpose. Why are we trying to match word boundaries here?

^[0-9a-fA-F]{8}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{12}$

(I tested the regex without the \b and the same strings match or don't match)

@alex-hofmann do you remember why you added those?

Is there a mispelled sentence the Cheat Sheet?

Hello again,

I was reading this :

/h.*llo/ the "STAR" matches any character(s) zero or more times... matches "hello", "heeeeeello", "hllo", "hwarwareallo"

A) This sems to be false : The STAR characters does not match any character. It is a special character for multi-items pattern.

• a REGEX-PATTERN followed by a STAR means "0 or more" of the preceding PATTERN.
• Additional parameters may specify : "more" means "as many as possible" (this is a "greedy" behavior) or "as little as possible" (this is "non-greedy" behavior).

So, you might have wanted to write : ".*"
"The POINT followed by a STAR matches any character...etc."

B) After "any character" you forgot to specify + "other than a new line character." as you did in previous comment, so in order to have consistent explanations, would it be better to add it?

-- KUTGW & best regards

Not able to edit the "show matches" box like regex101

Currently we follow a multiline colouring strategy

Required:

1. Treat all text as one
2. Provide support to edit and recolor

'username' regex doesn't match description

The regex for matching usernames doesn't match the given description.

Given description:

Alphanumeric string that may include _ and - having a length of 3 to 16 characters.
A username must not contain 2 underscores or 2 hyphens in a row. Also, it cannot have an
underscore, hyphen or a space at the start.

But it still matches strings like:

• -ab
• a--b
• a__

Fix:
Either change the description or the regex.

Here's a regex that follows the description except the minimum and maximum amount of characters allowed. /^[a-zA-Z0-9]+([_-]?[a-zA-Z0-9])*$/

issue with regex for ip address(ipv4)

I came across a small issue with the regex matching for ipv4, it's supposed to check that the ip address is in the range of 0.0.0.0 to 255.255.255.255 but this can fail when you get a number where just the first octet is larger then 255.
For example the ip address 341.25.015.22 passes because the starting 3 is ignored, then it appears valid.
Currently the regex for ipv4 is (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}
But I believe it should be (\b25[0-5]|\b2[0-4][0-9]|\b[01]?[0-9][0-9]?)(.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}
to include cases where the initial number may be out of range, but in range if you ignore the first character. The match should begin at the start of the word. Test cases that would be incorrect before, but are resolved by the suggestion below.
341.25.015.22
4248.254.1.1
972.52.4.12
1255.34.22.58

Simple email regex - matches invalid emails

https://ihateregex.io/expr/email/

The subdomain email is ok.

Add custom 404 page

Add regex for matching comments

By comments I mean comments in code, such as

// single line comment
/** multi
* line
* comment
*/

Mention \p{Letter} as alternative to [a-zA-Z]

See here for more info. Basically using \p{Letter} (or the shortened \p{L}) matches any unicode character that is a letter. This way you match things like ñ.

Add multi-language support [I can translate to Japanese]

This website is very very helpful for me.

And, Everyone rejoices if multi-language supported!

Support named captures

It would be great have named captures support, ie:

^A bell-like tone rings out from (?\w+)'s rapier, echoed by the sound of cracking bone as your (?:left|right) (?:arm|leg) snaps painfully.$

Domain match regex

It will match Domain name.

Regex:

(?:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\.)+[a-z0-9][a-z0-9-]{0,61}[a-z0-9]

Example:

test.com - valid
test--.main.com - invalid

(feature request) Dark theme

Thank you for the great work!
The site visualizes even very complex regexes with ease!! Love it!

I'd like to make just a suggestion, please: an optional dark theme.
I personally find them much easier on the eyes.

Thank you!

Doesn't the playground supprt "Lookarounds"?

"(?<=(T|t)he\s)(fat|mat)" should have matches in "The fat cat sat on the mat."

But I got an error.

Matcher on website doesn't show matches correctly on e.g. IPv6

Hi,

The following IPs do match the given regexp if used in grep(1) but not entirely on the website. I use bold (double star) in this issue to show which part were highlighted.

i-hate-regex/static/regexdata.json

Line 176 in dc4299e

"regex": "(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))",

Those should completely match:

• **2001:db8::**1
• **123::**456:789
• FE80:0000:0000:0000:0202:B3FF:FE1E:8329%eth0
• **fe80::**aaaa:bbbb:eeee:1111%eth0

Add regex to match numbers with comma for thousands and dot for decimals

Add regex to match numbers with comma for thousands and dot for decimals:

1,999,999.88

Regex for matching b64 encoded IP

This will match valid IPs from 0.0.0.0 to 255.255.255.255 which are base64 encoded.

let regex = /[MNO][CDSTijyz][4AEIMQUYcgk][012345uwxyz][LMNO][CDSTijyz][4AEIMQUYcgk][012345uwxyz][LMNO][ACDQSTgijwyz]([4=AEIMQUYcgk]{1}([012345=uwxyz]{1}([LMNO]{1}([ACDQSTgijwyz]{1}([4=AEIMQUYcgk]{1}([012345=uwxyz]{1}([MNO]{1}([ADQTgjwz]{1}([=AEIMQUYcgk]{1}([012345=wxyz]{1})?)?)?)?)?)?)?)?)?)?/gm;

The following IPs will match:

let matching_ips = [
  "MjU1LjI1NS4yNTUuMjU1",   // 255.255.255.255
  "MTIuMTIzLjE0Mi4xMjM=",   // 12.123.142.123
  "MjU1LjI1NS4yNTUuMg==",   // 255.255.255.2
  "MjU1LjIuMjUuMjU1",   // 255.2.25.255
  "MTIzLjEuMi4xMjM=",   // 123.1.2.123
  "NzguNTYuNDUuMg==",   // 78.56.45.2
  "MTIuNDUuMi4x",   // 12.45.2.1
  "OTEuMS4xLjE=",   // 91.1.1.1
  "MS4yLjMuNA==",   // 1.2.3.4
  … // and so on
]

The following won't:

let non_matching_ips = [
  "LTEuMi4zLjQ", // -1.2.3.4
  "MS4y", // 1.2,
  … // and so on
]

Unfortunately, there are some false-positives, as it matches for example 255.255.255.256, 256.256.256.256 and 1.02.3.4, which cannot be eradicated without massive efforts and making the expression even more unreadable.
But for extracting encoded IPs from some data to use it, for example as an IOC, this might be enough, and it's feasible to expect from a human being to check if an IP is valid.

Installing attempt failed on test "yarn dev"

I'm noob in yarn so sorry
Please help as there's step in failure:

$ yarn dev

 WARN  [email protected] is installed but ^10.1.1 is expected                                  03:04:07


 WARN  mode option is deprecated. You can safely remove it from nuxt.config                    03:04:10

ℹ Using Tailwind CSS from ~/assets/styles/tailwind.scss                       nuxt:tailwindcss 03:04:10

 FATAL  Your application tried to access tailwindcss, but it isn't declared in your dependencies; this makes the require call ambiguous and unsound.

Required package: tailwindcss (via "tailwindcss/defaultTheme")
Required by: /home/budi/Downloads/i-hate-regex/assets/styles/

Require stack:
- /home/budi/Downloads/i-hate-regex/assets/styles/tailwind.config.js

  
  Required package: tailwindcss (via "tailwindcss/defaultTheme")
  Required by: assets/styles/
  
  Require stack:
  - assets/styles/tailwind.config.js
  at require$$0.Module._resolveFilename (.pnp.cjs:26511:13)
  at Function.resolve (node:internal/modules/cjs/helpers:109:19)
  at _resolve (.yarn/cache/jiti-npm-1.16.0-a3cbfd13e3-28844cd691.zip/node_modules/jiti/dist/jiti.js:1:243302)
  at jiti (.yarn/cache/jiti-npm-1.16.0-a3cbfd13e3-28844cd691.zip/node_modules/jiti/dist/jiti.js:1:245428)
  at assets/styles/tailwind.config.js:1:95
  at Resolver.jiti [as _require] (.yarn/cache/jiti-npm-1.16.0-a3cbfd13e3-28844cd691.zip/node_modules/jiti/dist/jiti.js:1:247502)
  at Resolver.requireModule (.yarn/cache/@nuxt-core-npm-2.15.8-ea349e16fd-413e907a50.zip/node_modules/@nuxt/core/dist/core.js:381:29)
  at module.exports (.yarn/cache/@nuxtjs-tailwindcss-npm-3.4.3-4f2ebbe345-b9a2802f97.zip/node_modules/@nuxtjs/tailwindcss/lib/module.js:36:36)
  at async ModuleContainer.addModule (.yarn/cache/@nuxt-core-npm-2.15.8-ea349e16fd-413e907a50.zip/node_modules/@nuxt/core/dist/core.js:239:20)
  at async ModuleContainer.ready (.yarn/cache/@nuxt-core-npm-2.15.8-ea349e16fd-413e907a50.zip/node_modules/@nuxt/core/dist/core.js:51:7)
  at async Nuxt._init (.yarn/cache/@nuxt-core-npm-2.15.8-ea349e16fd-413e907a50.zip/node_modules/@nuxt/core/dist/core.js:478:5)

How to solve out ?

Search: Pressing 'enter' returns a 404

When using the search box, the search returns results correctly automatically. However, when you press the enter key, this returns a 404:

It doesn't seem to matter what the search is.

No license

It seems that you would want others to use and contribute to this software. It would be good to have a license (even just MIT/ISC) so people can use and modify it legally. However, I would recommend AGPLv3 since I think what you are doing is particularly important.

IPv4 and IPV6 support for CIDR Notation

It would be cool if matching valid CIDR address notation was also supported.
It's common in IT fields to match on what network an IP address is part of.
Route tables are my main use case.

https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing

User input Tags not escaping in the content editable

escape user input tags in matchbox

phone number无法匹配**固定号码

样例：** 哈尔滨市电话号码：[phone]
该规则的电话号码在**很常见：[四位区号]-[八位号码]

embed.ihateregex.io refused to connect.

i can not find embed picture by using chrome.it showed embed.ihateregex.io refused to connect.

Does anyone have the same problem as me？

Retain the cursor position after highlighting

Feature Request

The cursor inside the matches box jumps to the initial position after a person edits and highlighting is performed.
I was not able to find a proper method to get the cursor location inside a div and place the cursor at that position after I add the highlighting HTML.

This also makes it so that we cannot perform real-time highlighting. I've set a timeout:
components/post-components/MatchBox.vue

matchboxChanged(event) {
      var node = this.$refs.matchbox;
      // console.log(typeTimeout);
      if (typeTimeout) {
        clearTimeout(typeTimeout);
      }
      typeTimeout = setTimeout(() => {
        this.boxEdited();
      }, 2000);
    }

Add an "All Regex" page

There is no sitemap nor a page where all expressions are visible.

Desired result:
/expr/ should show all available expressions

Support for VerbalExpressions?

Hi,

The diagram rendering of a regexp is very nice and helpful.

Any chance adding support for Verbal Expressions? https://github.com/VerbalExpressions -> they seem to map in "words" very nicely the diagram blocks.

So the idea would be for a regexp like /^(http)(s)?(\:\/\/)(www\.)?([^\ ]*)$/
to also generate besides the diagram the VerbalExpression text alternative:

const tester = VerEx()
    .startOfLine()
    .then('http')
    .maybe('s')
    .then('://')
    .maybe('www.')
    .anythingBut(' ')
    .endOfLine();

for the desired programming language.

See https://github.com/VerbalExpressions/JSVerbalExpressions#testing-if-we-have-a-valid-url

Thank you.

Validate data.json and cheatsheet.json

As a contributor, I want to validate my recently added Regex