Regular Expressions 101

Explanation
Pro

^start of line

Group 1(\d+)

\d+a Unicode decimal digit, repeated at least once

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 2(\d+)

\d+a Unicode decimal digit, repeated at least once

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 3(\d+)

\d+a Unicode decimal digit, repeated at least once

Group 4([\w\d\.].*)?

?repeats the group contents below at most once:

Character Class[\w\d\.]

\wa Unicode word character

\da Unicode decimal digit

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

.*any Unicode 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

Detailed match information will be displayed here automatically.

25 tokens

^(\d+)\.(\d+)\.(\d+)([\w\d\.].*)?$

1.0.0
2.1.2
1.0.0a1
1.0.0a1+git
2.1.0.dev20230728+cu121
2.1.0a0+b5021ba
2.0.0.dev20230219+cu118

1.0.0
2.1.2
1.0.0a1
1.0.0a1+git
2.1.0.dev20230728+cu121
2.1.0a0+b5021ba
2.0.0.dev20230219+cu118