re = /^\s*\[[\-\w]*\d\]/m
str = '[ABC-123] Test message
[XYZ-312] Message test
[XYZ-ABCD-321] Awesome sauce
Test message
[ABC] Testing stuff
[Add ABC-123 files]
'
# Print the match result
str.scan(re) do |match|
puts match.to_s
end
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