re = /(?<=^|[^a-zA-Z0-9.+-])(?<version>(?<prefix>v?)(?<semver>(?<major>0|[1-9]\d*)\.(?<minor>0|[1-9]\d*)\.(?<patch>0|[1-9]\d*)(?:-(?<prerelease>(?:\d*[a-zA-Z-][0-9a-zA-Z-]*|[1-9]\d*|0)(?:\.(?:\d*[a-zA-Z-][0-9a-zA-Z-]*|[1-9]\d*|0))*))?(?:\+(?<build>[0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?))(?=[^a-zA-Z0-9.+-]|$)/m
str = 'Valid Semantic Versions
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
-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'
subst = '$1'
result = str.gsub(re, subst)
# Print the result of the substitution
puts result
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html