Match sematic version in string by regex - regex

Question

The definition of a valid "semantic version" can be found here.
I've got the official regex from semserver, but I want to match whole version without groups and text which is inside other words. For example from "Adobe Flash Player 3.20.1 version" I want to match only 3.20.1.
How should I modify this regex to get this information?
^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$
Here is the link for regex101 test https://regex101.com/r/YDXnbS/1
Here's the list of examples that should match, noting the first example should match only the version 3.20.1:
Valid Semantic Versions
Adobe Flash Player 3.20.1 version
0.0.4
1.2.3
10.20.30
1.1.2-prerelease+meta
1.1.2+meta
1.1.2+meta-valid
1.0.0-alpha
1.0.0-beta
1.0.0-alpha.beta
1.0.0-alpha.beta.1
1.0.0-alpha.1
1.0.0-alpha0.valid
1.0.0-alpha.0valid
1.0.0-alpha-a.b-c-somethinglong+build.1-aef.1-its-okay
1.0.0-rc.1+build.1
2.0.0-rc.1+build.123
1.2.3-beta
10.2.3-DEV-SNAPSHOT
1.2.3-SNAPSHOT-123
1.0.0
2.0.0
1.1.7
2.0.0+build.1848
2.0.1-alpha.1227
1.0.0-alpha+beta
1.2.3----RC-SNAPSHOT.12.9.1--.12+788
1.2.3----R-S.12.9.1--.12+meta
1.2.3----RC-SNAPSHOT.12.9.1--.12
1.0.0+0.build.1-rc.10000aaa-kk-0.1
99999999999999999999999.999999999999999999.99999999999999999
1.0.0-0A.is.legal
Invalid Semantic Versions
1
1.2
1.2.3-0123
1.2.3-0123.0123
1.1.2+.123
+invalid
-invalid
-invalid+invalid
-invalid.01
alpha
alpha.beta
alpha.beta.1
alpha.1
alpha+beta
alpha_beta
alpha.
alpha..
beta
1.0.0-alpha_beta
-alpha.
1.0.0-alpha..
1.0.0-alpha..1
1.0.0-alpha...1
1.0.0-alpha....1
1.0.0-alpha.....1
1.0.0-alpha......1
1.0.0-alpha.......1
01.1.1
1.01.1
1.1.01
1.2
1.2.3.DEV
1.2-SNAPSHOT
1.2.31.2.3----RC-SNAPSHOT.12.09.1--..12+788
1.2-RC-SNAPSHOT
-1.0.3-gamma+b7718
+justmeta
9.8.7+meta+meta
9.8.7-whatever+meta+meta
99999999999999999999999.999999999999999999.99999999999999999----RC-SNAPSHOT.12.09.1--------------------------------..12

Answer 1

I modified a regex found at iHateRegex by allowing the start to be start or a preceding space (?<=^| ), and the end to be end or a following space (?=$| ), which works for all your examples:
(?<=^| )(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?(?=$| )
See live demo.