re = /(?:^|\b(?<!\.))(?:1?\d?\d|2[0-4]\d|25[0-5])(?:\.(?:1?\d?\d|2[0-4]\d|25[0-5])){3}(?=$|[^\w.])/m
str = 'My input string & constraints are as follows :
IPv4 Range : 0.0.0.0 to 255.255.255.255 55.123.99.988 256.1.1.1
IPv4 address may / may not be present in the string
Valid Examples : this is an ip & this is an ip 200.100.2.32
String may start with IPv4 address
Valid Examples :
200.100.2.32 is an ip | Output : [\'200.100.2.32\']
Invalid Examples :
200.100.2.32is an ip | Output : []
String may end with IPv4 address
Valid Examples : the ip is 200.100.2.32
Output : [\'200.100.2.32\']
Invalid Examples : the ip is200.100.2.32
Output : []
String may contain an IPv4 address in the middle, and if it does - there will a space before and after the IPv4 address.
Valid Examples : the ip is 200.100.2.32 and it is ipv4 | Output : [\'200.100.2.32\']
Valid Examples : the ip is 200.100.2.32and it is ipv4 | Output : []
Multiple IPs may be present in a single string
Valid Examples : 200.100.2.32 100.50.1.16 | Output : [\'200.100.2.32\', \'100.50.1.16\']
Invalid Examples : 200.100.2.32.100.50.1.16 | Output : []
'
# 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