RegExLib.com - The first Regular Expression Library on the Web!

Use it for breaking-down a URI (URL, URN) reference into its main components: Scheme, Authority, Path, Query and Fragment. This is not a simple match regular expression. so it not works to verify a URI. It returns 1 matching group for each URI component. For example, for the following URI: http://regexlib.com/REDetails.aspx?regexp_id=x#Details returns: scheme="http", authority="regexlib.com", path="/REDetails.aspx", query="regexp_id=x" and fragment="Details". This is a W3C raccomandation (RFC 2396).

Email address validator. Should cover most of RFC 822, including unusual (but still valid) addresses. Does not restrict the top level domain size, but you're better off doing an nslookup or similar if you absolutely must have a valid domain. Accepts IP Addresses instead of the domain, with or without brackets. Believe it or not, this one is valid: !#$%^&*-+~/'`|{}@xyz.com Sorry looks like this site is mangling the quote and ampersand characters - you'll have to fix that yourself.

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])?$

This accepts RFC 2822 email addresses in the form:<br> [email protected] OR<br> Blah &lt;[email protected]&gt;<br> <br> RFC 2822 email 'mailbox':<br> mailbox = name-addr | addr-spec<br> name-addr = [display-name] "<" addr-spec ">"<br> addr-spec = local-part "@" domain<br> domain = rfc2821domain | rfc2821domain-literal<br> <br> local-part conforms to RFC 2822.<br> <br> domain is either:<br> An rfc 2821 domain (EXCEPT that the final sub-domain must consist of 2 or more letters only).<br> OR<br> An rfc 2821 address-literal.<br> (Note, no attempt is made to fully validate an IPv6 address-literal.)<br> <br> Notes:<br> This pattern uses (.NET/Perl only?) features named group "(?&lt;name&gt;)" and alternation/IF (?(name)).<br> <br> See <a href="http://regexadvice.com/forums/permalink/26742/26742/ShowThread.aspx#26742">this regexadvice.com thread</a> for more info, including a version that does not use .NET features.<br> <br> RFC 2822 (and 822) do allow embedded comments, whitespace, and newlines within *some* parts of an email address, but this pattern above DOES NOT.<br> <br> RFC 2822 (and 822) allow the domain to be a simple domain with NO ".", but this pattern requires a compound domain at least one "." in the domain name, as per RFC 2821 (4.1.2).<br> <br> RFC 2822 allows/disallows certain whitespace characters in parts of an email address, such as TAB, CR, LF BUT the pattern above does NOT test for these, and assumes that they are not present in the string (on the basis that these characters are hard to enter into an edit box).

Regular expression that matches Mexican RFC's (Registro Federal de Contribuyentes).

IPv6 text representation of addresses without compression from RFC 1884. This regular expression doesn't allow IPv6 compression (&quot;::&quot;) or mixed IPv4 addresses.

This Regex matches Mexican RFC's (Registro Federal de Contribuyentes) with 3 or 4 letters in the first section. It accepts spaces and dashes between sections.

Matches all IPv6 text representations as defined within RFC 2373. Fairly verbose

Matches canonical Uniform Resource Names (URNs) as defined in RFC 2141.

This is the best RFC 2822 ( http://www.faqs.org/rfcs/rfc2822 ) date format regular expression I could come up with. I've tested it, not very extensively though. This regex also validates obsolete standard, excluding comments anywhere.

Matches full and compressed IPv6 addresses as defined in RFC 2373 (http://www.faqs.org/rfcs/rfc2373.html). No useful captures. Various implementations require different terminators. (i.e. ^-$ or \b-\b)

A simple regex which should validate a domain name according to RFC 1035 updated to match domain names with hyphens

Registro Federal de Contribuyentes (RFC) , used in Mexico as a unique set of caracters for a person or corporation registration . Registro Federal de Contribuyentes utilizado en Mexico para el registro en hacienda.

Validates email addresses according to the RFC 822 specification. The only exception is the exclusion of control characters, which should be sufficient for human input from a keyboard.

I don't give a f*** to the RFC, fix it yourself for RFC, I just need a valid webresource location. So add forbidden characters as you need them in the character classes or use it as it is. This RegEx is not for searching valid URLs, just for validating. Look at the trailing $.

just another email validation perl regexp. I tryed to follow as much as possible the RFC 3696 don't hesitate to report.

This will match any valid RFC2822 e-mail address typed into web forms. If does not support comments, display name, or line folding. It does support quoted-strings in the local-part and domains by the RFC 1035 and proper ip addresses. It does relax the RFC1035 rule of not allowing numbers as the first character of a domain name (since they do exist in real life)

A pretty decent URL matching expression. I've followed most RFC guidelines, so it'll match most anything ya throw at it (And wont match what it's not supposed to). If you see any problems with it, please email me so I can make the appropriate changes :)

Validates an RFC 2822 email address, except does not allow most punctuation and non-ascii alphanumeric characters. Also does not take length requirements into account. Allows domain name and IP addresses, but ensures that the IP address entered is valid.

This is a robust email validation: the username part conforms with RFC 2822 (for instance, emails with tags ("+") are validated). The host part is checked for valid subdomains and its TLD is checked against all the 243 countries codes and the 14 ICANN'sTLDs. The host part also accepts IP with or without brackets.