regex101: PCRE (Legacy) Match Workspace

Group 1(((?:\<|\[)a href=\'|\")?((?:http:\/\/)?((?:www\.)?(?:[\w\d-_]*?\.)+(?:\w{2,4}))(?:\/?)(?:[\w\d-_]+))((?:(?:\'|\")(?:\>|\]))(?:[\w\d-_]+)(?:(?:\<|\[)\/a(?:\>|\])))?)

Group 2((?:\<|\[)a href=\'|\")?

?repeats the group contents below at most once:

1st Alternative(?:\<|\[)a href=\'

Non-Capturing Group(?:\<|\[)

1st Alternative\<

\<the literal < (60₁₀ / 74₈ / 3C₁₆)

2nd Alternative\[

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

a href=the literal text a href= (case insensitive)

\'the literal ' (39₁₀ / 47₈ / 27₁₆)

2nd Alternative\"

\"the literal " (34₁₀ / 42₈ / 22₁₆)

Group 3((?:http:\/\/)?((?:www\.)?(?:[\w\d-_]*?\.)+(?:\w{2,4}))(?:\/?)(?:[\w\d-_]+))

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

?repeats the group contents below at most once:

http:the literal text http: (case insensitive)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Group 4((?:www\.)?(?:[\w\d-_]*?\.)+(?:\w{2,4}))

Non-Capturing Group(?:www\.)?

?repeats the group contents below at most once:

wwwthe literal text www (case insensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Non-Capturing Group(?:[\w\d-_]*?\.)+

+repeats the group contents below at least once:

Character Class[\w\d-_]*?

*?matches any number of characters from the set below:

\wany word character

\da digit

-the literal - (45₁₀ / 55₈ / 2D₁₆)

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Non-Capturing Group(?:\w{2,4})

\w{2,4}any word character, repeated between 2 and 4 times

Non-Capturing Group(?:\/?)

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

Non-Capturing Group(?:[\w\d-_]+)

Character Class[\w\d-_]+

+matches at least one character from the set below:

\wany word character

\da digit

-the literal - (45₁₀ / 55₈ / 2D₁₆)

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Group 5((?:(?:\'|\")(?:\>|\]))(?:[\w\d-_]+)(?:(?:\<|\[)\/a(?:\>|\])))?

?repeats the group contents below at most once:

Non-Capturing Group(?:(?:\'|\")(?:\>|\]))

Non-Capturing Group(?:\'|\")

1st Alternative\'

\'the literal ' (39₁₀ / 47₈ / 27₁₆)

2nd Alternative\"

\"the literal " (34₁₀ / 42₈ / 22₁₆)

Non-Capturing Group(?:\>|\])

1st Alternative\>

\>the literal > (62₁₀ / 76₈ / 3E₁₆)

2nd Alternative\]

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

Non-Capturing Group(?:[\w\d-_]+)

Non-Capturing Group(?:(?:\<|\[)\/a(?:\>|\]))

Global pattern flags

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

s modifier: single line. Allows a dot to match line terminators

25 tokens

Regular Expression

(((?:\<|\[)a href=\'|\")?((?:http:\/\/)?((?:www\.)?(?:[\w\d-_]*?\.)+(?:\w{2,4}))(?:\/?)(?:[\w\d-_]+))((?:(?:\'|\")(?:\>|\]))(?:[\w\d-_]+)(?:(?:\<|\[)\/a(?:\>|\])))?)

New

[a href='http://vk.com/id11111']ntcn[/a]
<a href='http://vk.com/id111111'>ntcn</a>
http://vk.com/id71594164

Substitution

[a href='http://vk.com/id11111']ntcn[/a]
<a href='http://vk.com/id111111'>ntcn</a>
http://vk.com/id71594164