Regular Expressions 101

Explanation

Pro

^start of line

\d+a digit, repeated at least once

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

{3}repeats the group contents below exactly 3 times:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

\|the literal | (124₁₀ / 174₈ / 7C₁₆)

Negative Lookahead(?!(?:[1-9]\d{0,3}|[1-5]\d{4}|6[0-4]\d{3}|65[0-4]\d{2}|655[0-2]\d|6553[0-5])$)

Non-Capturing Group(?:[1-9]\d{0,3}|[1-5]\d{4}|6[0-4]\d{3}|65[0-4]\d{2}|655[0-2]\d|6553[0-5])

1st Alternative[1-9]\d{0,3}

Character Class[1-9]

1-9one character from 1 (49₁₀) to 9 (57₁₀)

\d{0,3}a digit, repeated between 0 and 3 times

2nd Alternative[1-5]\d{4}

Character Class[1-5]

1-5one character from 1 (49₁₀) to 5 (53₁₀)

\d{4}a digit, repeated exactly 4 times

3rd Alternative6[0-4]\d{3}

6the literal 6 (54₁₀ / 66₈ / 36₁₆)

Character Class[0-4]

0-4one character from 0 (48₁₀) to 4 (52₁₀)

\d{3}a digit, repeated exactly 3 times

4th Alternative65[0-4]\d{2}

65the literal text 65

Character Class[0-4]

0-4one character from 0 (48₁₀) to 4 (52₁₀)

\d{2}a digit, repeated exactly 2 times

5th Alternative655[0-2]\d

655the literal text 655

Character Class[0-2]

0-2one character from 0 (48₁₀) to 2 (50₁₀)

\da digit

6th Alternative6553[0-5]

6553the literal text 6553

Character Class[0-5]

0-5one character from 0 (48₁₀) to 5 (53₁₀)

$end of line

Group 1(.*)

.*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

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

^\d+(?:\.\d+){3}\|(?!(?:[1-9]\d{0,3}|[1-5]\d{4}|6[0-4]\d{3}|65[0-4]\d{2}|655[0-2]\d|6553[0-5])$)(.*)$

New

8.8.8.8|0
 (bad: port 0 not allowed)
8.8.8.8|1
 (good)
8.8.8.8|65536
8.8.8.8|6553
 (bad: port > 65535)
8.8.8.8|dawda
 (bad: char)