regex101: PCRE (Legacy) Match Workspace

Pro

^start of line

Positive Lookahead(?=.{9}$)

.{9}any character (except for line terminators), repeated exactly 9 times

$end of line

Positive Lookahead(?=.*(\d).*\1)

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

Group 1(\d)

\da digit

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

\1the text saved by group 1

Non-Capturing Group(?:\.*\d){1,9}

{1,9}repeats the group contents below between 1 and 9 times:

\.*the literal . (46₁₀ / 56₈ / 2E₁₆) , repeated any number of times

\da digit

\.*the literal . (46₁₀ / 56₈ / 2E₁₆) , 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

^(?=.{9}$)(?=.*(\d).*\1)(?:\.*\d){1,9}\.*$

New

.........
 - false - no numbers repeated
123456789
 - false - no numbers repeated
1.2.3.4.5
 - false - no numbers repeated
1...3...5
 - false - no numbers repeated
112345678
 - true - number 1 is repeated
1......1.
 - true - number 1 is repeated
11244.56.
 - true - number 1 and 4 are repeated
234.5.6.4
 - true - number 4 is repeated

Extraction

.........
 - false - no numbers repeated
123456789
 - false - no numbers repeated
1.2.3.4.5
 - false - no numbers repeated
1...3...5
 - false - no numbers repeated
112345678
 - true - number 1 is repeated
1......1.
 - true - number 1 is repeated
11244.56.
 - true - number 1 and 4 are repeated
234.5.6.4
 - true - number 4 is repeated