Given an IP address, the task is to validate this IP address with the help of Regex (Regular Expression) in C++ as a valid IPv4 address or IPv6 address. If IP address is not valid then print invalid IP address.
Examples:
Input: str = “203.120.223.13”
Output: Valid IPv4Input: str = “000.12.234.23.23”
Output: Invalid IPInput: str = “2F33:12a0:3Ea0:0302”
Output: Invalid IP
Input: str = “I.Am.not.an.ip”
Output: Invalid IP
Approach:
- Regex (Regular Expression) In C++ will be used to check the IP address.
- Range Specifications
Specifying a range of characters or literals is one of the simplest criteria used in a regex.
i) [a-z] ii) [A-Za-z0-9]
- In the above expression ([]) square brackets are used to specify the range.
- The first expression will match exactly one lowercase character.
- The second expression specifies the range containing one single uppercase character, one lowercase character, and a digit from 0 to 9.
- Now to include a ‘.’ as part of an expression, we need to escape ‘.’ and this can be done as :
[\\.0-9]
The above expression indicates an ‘.’ and a digit in the range 0 to 9 as a regex.
- regex_match() function is used to match the given pattern. This function returns true if the given expression matches the string. Otherwise, the function returns false.
Here is the implementation of the above approach.
C++
// C++ program to validate // IP address using Regex #include <bits/stdc++.h> using namespace std; // Function for Validating IP string Validate_It(string IP) { // Regex expression for validating IPv4 regex ipv4( "(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])" ); // Regex expression for validating IPv6 regex ipv6( "((([0-9a-fA-F]){1,4})\\:){7}([0-9a-fA-F]){1,4}" ); // Checking if it is a valid IPv4 addresses if (regex_match(IP, ipv4)) return "Valid IPv4" ; // Checking if it is a valid IPv6 addresses else if (regex_match(IP, ipv6)) return "Valid IPv6" ; // Return Invalid return "Invalid IP" ; } // Driver Code int main() { // IP addresses to validate string IP = "203.120.223.13" ; cout << Validate_It(IP) << endl; IP = "fffe:3465:efab:23fe:2235:6565:aaab:0001" ; cout << Validate_It(IP) << endl; IP = "2F33:12a0:3Ea0:0302" ; cout << Validate_It(IP) << endl; return 0; } |
Python3
# Python3 program to validate # IP address using Regex import re # Function for Validating IP def Validate_It(IP): # Regex expression for validating IPv4 regex = "(([0-9]|[1-9][0-9]|1[0-9][0-9]|" \ "2[0-4][0-9]|25[0-5])\\.){3}" \ "([0-9]|[1-9][0-9]|1[0-9][0-9]|" \ "2[0-4][0-9]|25[0-5])" # Regex expression for validating IPv6 regex1 = "((([0-9a-fA-F]){1,4})\\:){7}" \ "([0-9a-fA-F]){1,4}" p = re. compile (regex) p1 = re. compile (regex1) # Checking if it is a valid IPv4 addresses if (re.search(p, IP)): return "Valid IPv4" # Checking if it is a valid IPv6 addresses elif (re.search(p1, IP)): return "Valid IPv6" # Return Invalid return "Invalid IP" # Driver Code # IP addresses to validate IP = "203.120.223.13" print (Validate_It(IP)) IP = "fffe:3465:efab:23fe:2235:6565:aaab:0001" print (Validate_It(IP)) IP = "2F33:12a0:3Ea0:0302" print (Validate_It(IP)) # This code is contributed by avanitrachhadiya2155 |
Valid IPv4 Valid IPv6 Invalid IP
Time Complexity : O (N)
Auxiliary Space : O (1)
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