Regular Expressions 101

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Community Patterns

1

Factorization: Zero, Unit, Primes, or Composite?

.NET 7.0 (C#)
Description Inspects lines that contain only a character, let's say c, repeated n times. The name of the matching groups will tell you if n is 0, the unit 1, a prime number, or a composite number. Alternative ...
Submitted by kevinhp - 20 hours ago
1

semver2.0.0_franenguix

Python
Given a version number MAJOR.MINOR.PATCH, increment the: MAJOR version when you make incompatible API changes. MINOR version when you add functionality in a backward compatible manner. PATCH version when you make backward compatible bug fixes. A pre-release version MAY be denoted by appending a hyp...
Submitted by FranEnguix - a day ago (Last modified a day ago)
1

GPT multiline equations match

Python
substitutes \[...\] with $$...$$
Submitted by MyAiTree - 6 days ago
1

ChatGPT Equations to MD equations

Python
Substitute the oneliner GPT equations \(..\) to tex like i.e. $..$
Submitted by MyAITree - 6 days ago
1

Match a^nb^n

Python
Matches some number of a's followed by the same number of b's, usually written as a^nb^n for all natural numbers n. For regular expressions as formally defined in formal language theory, this is impossible, but modern day regex engines can do far more than match just regular languages. Note that eve...
Submitted by FieryIceStickie - 18 days ago
1

SVG viewbox parser

Python
for finding and extracting numbers from the viewbox attribute. see also my generalized SVG number regex. v2: added support for scientific notation
Submitted by riedler - 19 days ago (Last modified 14 days ago)
1

SVG number syntax

Python
for correctly parsing numbers in SVG attributes like path d or viewBox with regex v2: added support for scientific notation
Submitted by riedler - 19 days ago (Last modified 14 days ago)
1

ISO 8601 DURATION - Terraform Validation

Golang
This is made to validate an ISO 8601 input in a Terraform variable validation block: validation { condition = can(regex("^P(\\d+Y)?(\\d+M)?(\\d+D)?(T(\\d+H)?(\\d+M)?(\\d+S)?)?$", var.value)) error_message = "The value must be a valid ISO 8601 duration string representing time. (e.g. PT...
Submitted by anonymous - 21 days ago
1

Slash Separated Numbers

Golang
...
Submitted by Anonymous - 23 days ago
1

Telegram username

Python
Validates and obtains the Telegram user's username according to the rules for creating usernames
Submitted by okineadev - a month ago (Last modified a month ago)
1

Egyptian Phone Numbers regex Checker

Python
To check for Egyptian phone numbers using a regular expression Format of Egyptian phone numbers: It starts with 01 (indicating mobile numbers). Followed by one of the following digits representing the mobile provider: 0 for Vodafone. 1 for Etisalat....
Submitted by Assem ELQersh - a month ago
1

vozuskia (cs/sk)

Java 8
Addes a non-breaking space after any of the letters included in the [vozuskia] class.
Submitted by Manuel Souto Pico - 2 months ago
1

East pointer, reference and const to west.

Python
just as god intended. "T const" -> "const T"
Submitted by SpaghettDev - 2 months ago (Last modified 2 months ago)
1

Split Docker image into image name, tag and digest with all optional

Golang
Splits a Docker image string into the separate parts: image, tag, digest tag and digest are optional
Submitted by Roemer - 2 months ago
1

Command line parser

.NET 7.0 (C#)
Supports parameters such as keys and values, also parameters enclosed in quotes.
Submitted by Pavel Bashkardin - 2 months ago (Last modified 2 months ago)
1

Комментарии функции БСП

Python
Комментарии к функциям 1С
Submitted by binx@mail.ru - 2 months ago
1

search *user=.*

Python
for ansible regex_search in docker envs
Submitted by anonymous - 2 months ago
3

**japanese text** to bold <b>japanese text</b>

PCRE (PHP <7.3)
japanese text to bold japanese text 食べるんだ 食べるんだ
Submitted by kurokuroshii - 2 months ago (Last modified 2 months ago)
1

RFC3339 Validator

PCRE (PHP <7.3)
RFC3339 Validator
Submitted by anonymous - 3 months ago (Last modified 3 months ago)
1

.NET CSV parser

.NET 7.0 (C#)
Parses CSV files using comma (,) as delimiter and double quote (") as quoted-field tag. Features: Respects empty fields, including at the beginning and at the end of the line Respects line breaks in quoted fields
Submitted by kevinhp - 3 months ago
123...592

Community Library Entry

1

Regular Expression
Java 8

"
^(?:rate[(](?:(?:1[ ]+(hour|minute|day))|(?:[0-9]+[ ]+(hours|minutes|days)))[)])|(?:cron[(](?:(?:(?:[0-5]?[0-9])|[*])(?:(?:[-](?:(?:[0-5]?[0-9])|[*]))|(?:[/][0-9]+))?(?:[,](?:(?:[0-5]?[0-9])|[*])(?:(?:[-](?:(?:[0-5]?[0-9])|[*]))|(?:[/][0-9]+))?)*)[ ]+(?:(?:(?:[0-2]?[0-9])|[*])(?:(?:[-](?:(?:[0-2]?[0-9])|[*]))|(?:[/][0-9]+))?(?:[,](?:(?:[0-2]?[0-9])|[*])(?:(?:[-](?:(?:[0-2]?[0-9])|[*]))|(?:[/][0-9]+))?)*)[ ]+(?:(?:[?][ ]+(?:(?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:(?:[-](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:[/][0-9]+)?)|(?:[/][0-9]+))?(?:[,](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:(?:[-](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:[/][0-9]+)?)|(?:[/][0-9]+))?)*)[ ]+(?:(?:(?:[1-7]|(?:SUN|MON|TUE|WED|THU|FRI|SAT))[#][0-5])|(?:(?:(?:(?:[1-7]|(?:SUN|MON|TUE|WED|THU|FRI|SAT))L?)|[L*])(?:(?:[-](?:(?:(?:[1-7]|(?:SUN|MON|TUE|WED|THU|FRI|SAT))L?)|[L*]))|(?:[/][0-9]+))?(?:[,](?:(?:(?:[1-7]|(?:SUN|MON|TUE|WED|THU|FRI|SAT))L?)|[L*])(?:(?:[-](?:(?:(?:[1-7]|(?:SUN|MON|TUE|WED|THU|FRI|SAT))L?)|[L*]))|(?:[/][0-9]+))?)*)))|(?:(?:(?:(?:(?:[1-3]?[0-9])W?)|LW|[L*])(?:(?:[-](?:(?:(?:[1-3]?[0-9])W?)|LW|[L*]))|(?:[/][0-9]+))?(?:[,](?:(?:(?:[1-3]?[0-9])W?)|LW|[L*])(?:(?:[-](?:(?:(?:[1-3]?[0-9])W?)|LW|[L*]))|(?:[/][0-9]+))?)*)[ ]+(?:(?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:(?:[-](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:[/][0-9]+)?)|(?:[/][0-9]+))?(?:[,](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:(?:[-](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:[/][0-9]+)?)|(?:[/][0-9]+))?)*)[ ]+[?]))[ ]+(?:(?:(?:[12][0-9]{3})|[*])(?:(?:[-](?:(?:[12][0-9]{3})|[*]))|(?:[/][0-9]+))?(?:[,](?:(?:[12][0-9]{3})|[*])(?:(?:[-](?:(?:[12][0-9]{3})|[*]))|(?:[/][0-9]+))?)*)[)])$
"
g
Open regex in editor

Description

This validates AWS EventBridge scheduling expressions using the rate() and cron() formats.

It may not catch all invalid expressions, but it should properly validate all valid expressions, as demonstrated in the unit tests. Please let me know if I missed any valid expressions.

Originally attempted this using named capture groups and named back-references to reduce duplication. Unfortunately, named capture support is tricky, so they were all converted to duplicated non-capturing groups instead.

Submitted by Evan S Kaufman <evan@evanskaufman.com> - 8 months ago (Last modified 6 months ago)