re = /^%(\w{3})\s+(\d+)\s*([0-9]+\s?:\s?[0-9]+\s?:\s?[0-9]+):[0-9]+\s*(\d{4})?\s*\S*\s*(.*)\/(\d+)\/\S*:(?:(.*);)?(.*)/
str = '%May 11 10:03:51:122 2000 AB-CD-E SSH/6/SSH_LOGOUT: STEL user manager (IP: 172.0.0.0) logged out.
'
# 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