Regular Expressions 101

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Community Patterns

2

Replace \n by <br />

ECMAScript (JavaScript)
Replace non-ending string \n by the HTML tag
Submitted by anonymous - 11 years ago
7

split URL into location-resource-params (JavaScript)

ECMAScript (JavaScript)
Extract resource location, name and query parameters from a URL (JavaScript version)
Submitted by cebence - 10 years ago
4

Credit Card Number

PCRE (PHP <7.3)
Validates Credit Card Numbers of different type. Supports Visa, MasterCard, American Express, Diners Club, Discover and JCB Taken from http://www.regular-expressions.info/creditcard.html If you want to support only a particular type, customise it based on following....
Submitted by Ehsan - 9 years ago
11

find all link(<a>) tags expect your links in href attribute

ECMAScript (JavaScript)
YourLink - not found AnotherLink - found
Submitted by KoT - 9 years ago
8

Alphanumeric and Spaces

PCRE (PHP <7.3)
Alow alphanumeric characters and spaces
Submitted by JTN - 9 years ago (Last modified a year ago)
12

Full url parse, domain, path, params

ECMAScript (JavaScript)
no description available
Submitted by anonymous - 9 years ago
14

RFC3339 DateTime

Recommended
PCRE (PHP <7.3)
Validates a RFC3339 DateTime format. Does not validates the Data
Submitted by anonymous - 9 years ago
6

reg Ex number range check

PCRE (PHP <7.3)
Hi, I am trying to get a reg ex that will test a number range and also allow european number convention like , for decimal point. I have this one for range check - ^(4-9{3}|1-9{4,5}|12{6}|30-4{5}|3500000)$ and I have this one for allow comma ^\s?([\d\.]+(\,\d{1,2})?|\,\d{1,2})\s$ but I need a comb...
Submitted by TimJ - 10 years ago
11

Codice fiscale

PCRE (PHP <7.3)
Check "codice fiscale"
Submitted by Luca - 9 years ago
4

Strip multi-line (star) comments from JavaScript, while leaving any CDATA sections intact.

PCRE (PHP <7.3)
This regular expression removes multi-line (star) comments from JavaScript, while leaving any CDATA sections intact. Use the global (g) modifier to match them all (if you plan to use PHP's preg_replace, the g modifier is not necessary), and use the (s) modifier to make dots match newlines (this will...
Submitted by Dane MacMillan - 12 years ago
9

Removing an XML Nodes namespace prefix from a XML string wit

PCRE (PHP <7.3)
no description available
Submitted by anonymous - 11 years ago
10

Just validate one sequence of

PCRE (PHP <7.3)
sdfs sdfs FLBREV00022230 dsfsdfs sdfsf FLBREV00022234 In this case is false
Submitted by Fiipe - 10 years ago
11

remove comments from php code

PCRE (PHP <7.3)
no description available
Submitted by anonymous - 9 years ago
3

split sentence regex

PCRE (PHP <7.3)
no description available
Submitted by anonymous - 9 years ago
10

Valid Telephone Number

ECMAScript (JavaScript)
This regex validates varying types of telephone numbers.
Submitted by Adam Recvlohe - 9 years ago
4

Prime number regex

PCRE (PHP <7.3)
no description available
Submitted by originally "Abigail", comp.lang.perl.misc - 11 years ago
4

Get stuff inside <a> tags

PCRE (PHP <7.3)
Get stuff inside tags, which are between certain words
Submitted by Jerry - 11 years ago
7

PAN CARD validation

PCRE (PHP <7.3)
checks for valid PAN card for Indian users.
Submitted by karan thakkar - 10 years ago
1

Regular expression to remove all puncutation

Python
Removes all of the puncutation present inlcuding \n,\t,\r
Submitted by Abhinav Gupta - 10 years ago
10

MikroTik FireWall

PCRE (PHP <7.3)
Regex used in Splunk to extract fields from Mikrotik FW. NOTES: Mikrotik must be configured to use "BSD Syslog" format FW rules must add, as log prefix, the action: drop accep...
Submitted by HappyIdeasMaker - 9 years ago
1...34567...900

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) - a year ago