Regex: Matches _lower_camel_case words for ActiveRecord migrations

lcc_ar_migration.regex

http://regex101.com/r/mV8rA7

/(?:_([^_.]+))+?/g

01_create_cats.rb
02_create_all_the_dogs.rb

/(?:_([^_.]+))+?/g
(?:_([^_.]+)) Non-capturing Group 1 to infinite times [lazy]
_ Literal _
1st Capturing group ([^_.]+)
Negated char class [^_.] 1 to infinite times [greedy] matches any character except:
_. One of the following characters _.
g modifier: global. All matches (don't return on first match)