Regular Expressions 101

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Community Patterns

1

ENEL T5 Mono

PCRE (PHP <7.3)
T
Submitted by anonymous - 2 years ago
1

extract <*n or <n where n is a number

Golang
see https://stackoverflow.com/questions/76228402/regex-to-extract-n-where-n-is-digit
Submitted by code_monk - 2 years ago
1

prod validation

PCRE2 (PHP >=7.3)
valid prod
Submitted by CW - 2 years ago (Last modified 2 years ago)
1

Discord GuildEmoji

PCRE2 (PHP >=7.3)
Matches a custom emoji from discord. Group 1: Optional, "a" means animated, a gif. Group 2: Emoji Name. Group 3: Emoji Id;
Submitted by revelcw - 2 years ago
1

Capture URL without Query Parameters

ECMAScript (JavaScript)
Capture URL without Query Parameters /^(+).*/gm
Submitted by anonymous - 2 years ago
1

wip; 匹配malloc申请的内容和使用的不一致

PCRE2 (PHP >=7.3)
匹配malloc申请的内容和使用的不一致
Submitted by zyf - 2 years ago
1

Home

Golang
Dj dus er geen je een je aan je enige eerst een he we er
Submitted by Webmaster - 2 years ago
1

Time Zone UTC Offsets in actual use for ISO 8601 / RFC 3339 Date Times (Museum of Bad Data)

ECMAScript (JavaScript)
Time Zone UTC Offsets in actual use for ISO 8601 / RFC 3339 Date Times (Museum of Bad Data) https://regex101.com/library/F21Glr Matches only (and every) UTC offset that is in actual use and valid under ISO 8601 and RFC 3339 (Y'know, the '2008-08-08T08:08:08+05:00' looking one, this is the plus/min...
Submitted by Philip Flip Kromer - 2 years ago
1

Four-Digit Leap Years post-Y0 (AD/BCE) (Museum of Bad Data)

PCRE2 (PHP >=7.3)
This will match all four-digit years that are leap years, using the "either (multiple of four but not a multiple of 100) OR (multiple of 400)" rule. Explained / ^(...
Submitted by Philip Flip Kromer - 2 years ago (Last modified 2 months ago)
1

Get <NIC>

Python
Get NICs from string
Submitted by anonymous - 2 years ago
1

Strong Matcher for ISO 8601 / RFC 3339 Date Times; rejects bad TZ offsets, illegal times (Museum of Bad Data)

ECMAScript (JavaScript)
Handles many nuanced cases around time zone offsets, leap seconds and leap days. References: List of UTC Offsets RFC 3339, the stricter rules that most systems use in practice ISO 8601, the widely known name for this format...
Submitted by Philip Flip Kromer (@mrflip) - 2 years ago
1

Riedler's 2nd URL regex

Java 8
why did I make this?
Submitted by Riedler - 2 years ago
-1

Discord name with both old and new name support

PCRE2 (PHP >=7.3)
This discord regex supports both the new and the old version of discord names. Old: NAME#[0001-9999] Between 2 and 32 characters....
Submitted by Fy17 - 2 years ago
1

match eslint packages other than next.js

ECMAScript (JavaScript)
This could be used to group eslint stuff in renovate config for a next.js project. Since you're intended to keep eslint-plugin-next at the same version as next itself, you would want to group it with next instead. Using negative lookahead we can ignore eslint-config-next (or anything else you may wi...
Submitted by Mitsunee - 2 years ago (Last modified 2 years ago)
1

Prometheus Exposition metric line

Rust
Prometheus exposition metric line format. Parses metric lines with named capture groups for metric name, labels, value, and timestamp. Excludes comment, type, and help lines. https://prometheus.io/docs/instrumenting/exposition_formats/#line-format
Submitted by james-jra - 2 years ago
1

URL Cleaner

PCRE2 (PHP >=7.3)
It just cleans up urls.
Submitted by anonymous - 2 years ago (Last modified a year ago)
1

Wikipedia ISO 4217 (Currency Codes) table to C# enum

.NET 7.0 (C#)
This converts the values in this) table to C# code. Example: pulic enum Iso4217 { /* output here */...
Submitted by Diemaco - 2 years ago
1

Clean Date Finder

PCRE2 (PHP >=7.3)
Find dates of multiple formats in a clean way Searchable Formats: -Month day year -Month day, year -Mon day year...
Submitted by anonymous - 2 years ago
1

Password validation

ECMAScript (JavaScript)
Password requirements: Contains at least one uppercase letter. Contains at least one lowercase letter. Contains at least one digit. Does not contain any whitespace characters. Has a minimum length of 8 characters.
Submitted by anonymous - 2 years ago
1

3 letter word finder

PCRE2 (PHP >=7.3)
finds any 3 letter words in a text
Submitted by anonymous - 2 years ago
1...326327328329330...902

Community Library Entry

1

Regular Expression
ECMAScript (JavaScript)

/
(?=(?:^(?:\d\d\d\d-(?:0[1-9]|10|11|12)-(?:0[1-9]|1[0-9]|2[0-8])|\d\d\d\d-(?:0[13-9]|10|11|12)-(?:29|30)|\d\d\d\d-(?:0[13578]|10|12)-31|(?:\d\d[2468][048]|\d\d0[48]|\d\d[13579][26])-02-29|(?:[02468][048]00|[13579][26]00)-02-29)T(?:(?:0[0-9]|1[0-9]|2[0-3]):(?:[0-5][0-9]):(?:[0-5][0-9]))(?:\.\d\d\d)?(?:Z|[\+\-](?:0[0-9]|1[012]):00|\+0[34569]:30|\+10:30|-0[39]:30|\+1[34]:00|\+0[58]:45|\+12:45)$)|^(?:1972|198[1235]|199[2347]|2012|2015)-06-30T23:59:60Z$|^(?:197[2-9]|1987|1989|199[058]|2005|2008|2016)-12-31T23:59:60Z$)(?!.*-00:00$)^(\d\d\d\d)-(\d\d)-(\d\d)T(\d\d):(\d\d):(\d\d)(?:\.(\d\d\d))?((Z)|([\+\-])(\d\d):(\d\d))$
/
gm
Open regex in editor

Description

Handles many nuanced cases around time zone offsets, leap seconds and leap days.

References:

Pattern

(?=
  (?:^
    (?: # All non-leap-second YYYY-MM-DD parts:
      \d\d\d\d-(?:0[1-9]  |10|11|12)-(?:0[1-9]|1[0-9]|2[0-8])   # Days 01-28
    | \d\d\d\d-(?:0[13-9] |10|11|12)-(?:29|30)                  # Days 29+30
    | \d\d\d\d-(?:0[13578]|10   |12)-31                         # Day 31
    | (?:\d\d[2468][048]|\d\d0[48]|\d\d[13579][26])-02-29       # leap years not divisible by 100
    | (?:[02468][048]00|[13579][26]00)-02-29                    # leap years divisible by 400
    )
    T
    (?:(?:0[0-9]|1[0-9]|2[0-3]):(?:[0-5][0-9]):(?:[0-5][0-9]))  # time part
    (?:\.\d\d\d)?                                               # ms part (optional)
    (?:Z|[\+\-](?:0[0-9]|1[012]):00|\+0[34569]:30|\+10:30|-0[39]:30|\+1[34]:00|\+0[58]:45|\+12:45)
  $)
  |^(?:1972    |198[1235]|199[2347]|2012|2015     )-06-30T23:59:60Z$ # all june leapsecs
  |^(?:197[2-9]|1987|1989|199[058] |2005|2008|2016)-12-31T23:59:60Z$ # all december leapsecs
)
(?!.*-00:00$) # if given a -00:00 offset reject unconditionally, psychhhh
# OK! Since only valid times are now possible, we can use a loose pattern match to parse.
^(\d\d\d\d)-(\d\d)-(\d\d)T(\d\d):(\d\d):(\d\d)(?:\.(\d\d\d))?((Z)|([\+\-])(\d\d):(\d\d))$

Test cases

//	accept: Exemplars
2008-02-03T04:05:06.007Z
2008-02-03T04:05:06Z
0000-01-01T00:00:00.000Z
9999-12-31T59:59:59.999Z
9999-12-31T59:59:59Z
2008-02-03T04:05:06.007+12:45
2008-02-03T04:05:06+03:30
0000-01-01T00:00:00.007-09:30
0000-02-29T04:05:06.007+14:00
9999-12-31T23:59:59.999+12:00
9999-12-31T23:59:59-12:00
//	accept: Leap day, year is multiple of four
0004-02-29T04:05:06Z
0096-02-29T04:05:06Z
1560-02-29T04:05:06Z
2004-02-29T04:05:06Z
2020-02-29T04:05:06Z
2032-02-29T04:05:06Z
9996-02-29T04:05:06Z
//	accept: Leap day, year is Multiple of 400
0000-02-29T04:05:06Z
1200-02-29T04:05:06Z
1600-02-29T04:05:06Z
2000-02-29T04:05:06Z
3600-02-29T04:05:06Z
8000-02-29T04:05:06Z
9600-02-29T04:05:06Z
//	accept: Day in range for month
2008-01-30T04:05:06Z
2008-03-30T04:05:06Z
2008-04-30T04:05:06Z
2008-05-30T04:05:06Z
2008-06-30T04:05:06Z
2008-07-30T04:05:06Z
2008-08-30T04:05:06Z
2008-09-30T04:05:06Z
2008-10-30T04:05:06Z
2008-11-30T04:05:06Z
2008-12-30T04:05:06Z
2008-01-31T04:05:06Z
2008-02-31T04:05:06Z
2008-03-31T04:05:06Z
2008-05-31T04:05:06Z
2008-07-31T04:05:06Z
2008-08-31T04:05:06Z
2008-10-31T04:05:06Z
2008-12-31T04:05:06Z
//	accept: leap second
1972-06-30T23:59:60Z
1981-06-30T23:59:60Z
1982-06-30T23:59:60Z
1983-06-30T23:59:60Z
1985-06-30T23:59:60Z
1992-06-30T23:59:60Z
1993-06-30T23:59:60Z
1994-06-30T23:59:60Z
1997-06-30T23:59:60Z
2012-06-30T23:59:60Z
2015-06-30T23:59:60Z
1972-12-31T23:59:60Z
1973-12-31T23:59:60Z
1974-12-31T23:59:60Z
1975-12-31T23:59:60Z
1976-12-31T23:59:60Z
1977-12-31T23:59:60Z
1978-12-31T23:59:60Z
1979-12-31T23:59:60Z
1987-12-31T23:59:60Z
1989-12-31T23:59:60Z
1990-12-31T23:59:60Z
1995-12-31T23:59:60Z
1998-12-31T23:59:60Z
2005-12-31T23:59:60Z
2008-12-31T23:59:60Z
2016-12-31T23:59:60Z
//	REJECT: Out of range
10000-02-29T04:05:06Z
2008-00-30T04:05:06Z
2008-13-30T04:05:06Z
2008-02-30T04:05:06Z
2008-04-31T04:05:06Z
2008-06-31T04:05:06Z
2008-09-31T04:05:06Z
2008-11-31T04:05:06Z
2008-12-32T04:05:06Z
2008-12-99T04:05:06Z
2008-12-00T04:05:06Z
//	REJECT: Hour/min/sec out of range
2008-12-08T60:05:06Z
2008-12-08T04:60:06Z
2008-12-08T04:99:06Z
9999-12-31T59:59:61.999Z
2008-02-03T04:05:61.999Z
2008-02-03T04:05:61Z
//	REJECT: Negative dates not accepted
-2000-02-29T04:05:06Z
//	REJECT: Malformed
2008-02-0304:05:06Z
20080203T040506Z
2008-02-03T04:05:06007Z
2008-02-03T04:05:06.7Z
2008-02-03T04:05:06.07Z
2008-02-03T04:05:06.0007Z
2008-02-03T04:05:06
2008-02-03T04:05:06.Z
//	REJECT: no leap second
1978-06-30T23:59:60Z
//	REJECT: assumes no future leap seconds
2024-12-31T23:59:60Z
2099-12-31T23:59:60Z
9999-12-31T23:59:60Z
//	REJECT: leap seconds only in UTC format
2005-12-31T23:59:60+00:00
2008-12-31T23:59:60+00:00
//	REJECT: Not a leap day, not a multiple of four
2003-02-29T04:05:06Z
2037-02-29T04:05:06Z
2038-02-29T04:05:06Z
2039-02-29T04:05:06Z
9997-02-29T04:05:06Z
9998-02-29T04:05:06Z
9999-02-29T04:05:06Z
//	REJECT: Not a leap day, mult of 100
0100-02-29T04:05:06Z
1000-02-29T04:05:06Z
2100-02-29T04:05:06Z
2200-02-29T04:05:06Z
3500-02-29T04:05:06Z
3700-02-29T04:05:06Z
Submitted by Philip Flip Kromer (@mrflip) - 2 years ago