regex101: PCRE (Legacy) Substitution Workspace

Pro

(?i)applies the following effective flags to the remainder of the pattern: gmi

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

^start of line

Non-Capturing Group(?:https?:\/\/)

httpthe literal text http (case insensitive)

s?optionally matches the literal s (115₁₀ / 163₈ / 73₁₆) (case insensitive)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Non-Capturing Group(?:w{3}\.)?

?repeats the group contents below at most once:

w{3}the literal w (119₁₀ / 167₈ / 77₁₆) (case insensitive), repeated exactly 3 times

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 1([^\r\n]+?)

Negated Character Class[^\r\n]+?

+?matches at least one character outside the set below:

\ra carriage return (ASCII 13)

\na line-feed (newline) character (ASCII 10)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 2([a-z0-9]{2,6}(?:\.[a-z0-9]{2,6})?)

Character Class[a-z0-9]{2,6}

{2,6}matches between 2 and 6 characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case insensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Non-Capturing Group(?:\.[a-z0-9]{2,6})?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[a-z0-9]{2,6}

{2,6}matches between 2 and 6 characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case insensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

\/?optionally matches the literal / (47₁₀ / 57₈ / 2F₁₆)

Group 3(.*)

.*any character (except for line terminators), repeated any number of times

$end of line

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

25 tokens

Regular Expression

(?i)^(?:https?:\/\/)(?:w{3}\.)?([^\r\n]+?)\.([a-z0-9]{2,6}(?:\.[a-z0-9]{2,6})?)\/?(.*)$

New

https://stackoverflow.com/questions/ask
https://stackoverflow.co.uk/questions/ask
https://www.stackoverflow.com/questions/ask
http://www.stackoverflow.co.uk/questions/ask
http://www.stackoverflow.co.uk/
http://www.stackoverflow.co.uk

Extraction

https://stackoverflow.com/questions/ask
https://stackoverflow.co.uk/questions/ask
https://www.stackoverflow.com/questions/ask
http://www.stackoverflow.co.uk/questions/ask
http://www.stackoverflow.co.uk/
http://www.stackoverflow.co.uk