This regular expression is too simple - if you want to it to be accurate, you need to check that the numbers are between 0 and , with the regex above accepting in any position. You want to check for with 25 , or any other value 2 , or any value or less with ? IPv6 addresses take the form of 8 bit hex words delimited with the colon : character. In this case, we check for 7 words followed by colons, followed by one that is not. If a word has leading zeroes, they may be truncated, meaning each word may contain between 1 and 4 hex digits. This, however, is insufficient.
Regular expressions for IP addresses, CIDR ranges and hostnames
Perl | Extract IP Address from a String using Regex - GeeksforGeeks
I have recently had cause to find regular expressions that allow me to determine if some user input is an IP address, IP address range in CIDR notation or a hostname. Remember that these all have to be entered on one line. You can test them out in your browser using the excellent Regex Pal site. Thanks to Gavin in the comments]. Thanks to Oleksiy and Rui Lapa in the comments for pointing this out. Thanks to Thomas in the comments for pointing out this error. I found that the mask group is evaluated from left to right as expected and that when using these to find CIDR addresses the match stops at the first number when there are more.
RegEx: Find IP Addresses in a File Using Grep
Let suppose a situation in which you have to read some specific data like phone numbers, email addresses, dates, a collection of words etc. How can you do this in a very efficient manner? The Best way to do this by Regular Expression. Let take an example in which we have to find out only email from the given input by Regular Expression. Examples: Input : Hello shubhamg gmail.
Skip to content. Related Articles. Last Updated : 01 Feb, Every computer connected to the Internet is identified by a unique four-part string, known as its Internet Protocol IP address.