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Checks domain names. This validates domains based on latest specifications (RFCs 952 and 1123 dealing with hostnames and RFC 1035 dealing with domain name system requirements) except that it only includes realistic fully-qualified domains: 1. requires at least one subdomain 2. allows shortest top-level domains like "ca", and "museum" as longest. Other validation rules: 1. Labels/parts should be seperated by period. 2. Each label/part has maximum of 63 characters. 3. First and last character of label must be alphanumeric, other characters alphanumeric or hyphen. 4. Does not check maxlength of domain which incidentally is 253 characters of text (255 binary representation). For a regular expression that matches ALL domains: ^([a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?\.)*[a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?$

Regular expression for validating a decimal IP address. Matches 4 groups of from 1 to 3 digits, where each group of digits ranges from 0 to 255 in value. Groups of digits must be separated by a single period (.) with no other formatting characters present. Uses conditional regex with lookahead syntax to prevent a match on a period following the final group of digits.

Using other regular experssions from this page, combining others for email addresses, and mixing in my own ideas - I came up with this regular expression. Can be used to validate input into a database.

Validation of a Folder Name. Excludes all forbidden characters

I needed a regular expression to break urls into labled parts. This is what I came up with. Got a few ideas from regexlib.com and from this msdn article. http://msdn.microsoft.com/library/default.asp?url=/library/en-us/script56/html/reconbackreferences.asp http://www.domain.com/folder does return a match but will not grab the folder name unless there is "/" at the end. http://www.domain.com/folder/

This regular expression match any valid file path. It checks local drives and network path. The file extension is required.

RegExp for validating the format of IP Addresses. This works great with the ASP.NET RegularExpressionValidator server control.

Hopefully an all-encompassing expression to validate a URL. Supports an optional protocol, either a domain or IP address, an optional port number and an optional path.

This regexp matches all existing TLDs (Top-Level Domains) according to IANA specifications as of 14/07/2007.

Cheap and cheerful URL checker. Requires a http/https/ftp at the start and will then allow anything starting with at least a <something>.<something>.<something> then valid characters separated by dots and slashes

Validates windows path and invalidates UNC path

It matches .jpg files. It allows for a dot in the path. A dot may occur in such directories as: C:\Documents and Settings\roman.lukyanenko\Desktop\stuff\b_card2.txt or C:\Windows\Microsoft.NET etc

Version 1.3.0: I needed a regexp to validate URL's without the ht(f)tp(s):// and include North American domains (like .us and .ca) and there didn't seem to be one available...so I created one. It will also work with ASP QueryStrings and anchor URL's. If you have a problem with the expression or have any suggestions to improve, please write me and let me know. Added .uk domain and expression now allows for URLs that contain JSP session IDs. 4/14/04 - added ability to include URLs that start with server names.

Modified Joe Lynwood's to allow zero amounts. Handles US Dollars including zero dollars.

*CORRECTED: Again thanks for all the comments below. If you want to include internal domain as well change the partial code (\.[\w-_]+)+ to (\.[\w-_]+)? See the comments below* This is the regular expression I use to add links in my email program. It also ignores those suppose-to-be commas/periods/colons at the end of the URL, like this sentence "check out http://www.yahoo.com/." (the period will be ignored) Note that it requires some modification to match ones that dont start with http.

will match free floating valid protocol + urls in text ... will not touch the ones wrapped in a tag, so that you can auto-link the ones that aren't :) couple of things to know : 1. if the url is next to a tag this won't work (eg : <br>http://www.acme.com), the url must either start with a \s, \n or any character other than >. 2. the pattern will match the preceding \s and \n too, so when you replace put them back in place $1 will either be \s or \n, $2 will be the exact match vb usage : set re = New RegExp re.Pattern ="(\s|\n|^)(\w+://[^\s\n]+)" strResult = re.Replace(strText, "$1<a href='$2' target='_new'>$2</a>")

It matches .jpg files. It allows for a dot in the path. A dot may occur in such directories as: C:\Documents and Settings\roman.lukyanenko\Desktop\stuff\b_card2.jpg or C:\Windows\Microsoft.NET etc

Url matching

Matches files extension

Used to match windows filenames. Fails if there is leading or trailing spaces. Fails if the input contains /\:*?"<>| . Fails if the input begins or ends with '.'