Email Validation Regular Expression

[qwibbles]

How about this regular expression i was pointed to by a forum to validate email addresses!!!

http://www.ex-parrot.com/~pdw/Mail-RFC822-Address.html

I could not believe it.

I think this one is a bit more reasonable

1

/^[-_.a-z0-9]+@(([-_a-z0-9]+\.)+(ad|ae|aero|af|ag|ai|al|am|an|ao|aq|ar|arpa|as|at|au|aw|az|ba|bb|bd|be|bf|bg|bh|bi|biz|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|com|coop|cr|cs|cu|cv|cx|cy|cz|de|dj|dk|dm|do|dz|ec|edu|ee|eg|eh|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gh|gi|gl|gm|gn|gov|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|in|info|int|io|iq|ir|is|it|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|mg|mh|mil|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|museum|mv|mw|mx|my|mz|na|name|nc|ne|net|nf|ng|ni|nl|no|np|nr|nt|nu|nz|om|org|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|pro|ps|pt|pw|py|qa|re|ro|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|sk|sl|sm|sn|so|sr|st|su|sv|sy|sz|tc|td|tf|tg|th|tj|tk|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|um|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw)|(([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5])\.){3}([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5]))$/i

or
2

/^[^a-zA-Z][a-zA-Z0-9_]+([.][a-zA-Z0-9_]+)*[@][a-zA-Z0-9_]+([.][a-zA-Z0-9_]+)*[.][a-zA-Z]{2,4}$/

or from drupal common.inc

3

function valid_email_address($mail) {
  $user = '[a-zA-Z0-9_\-\.\+\^!#\$%&*+\/\=\?\`\|\{\}~\']+';
  $domain = '(?:(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.?)+';
  $ipv4 = '[0-9]{1,3}(\.[0-9]{1,3}){3}';
  $ipv6 = '[0-9a-fA-F]{1,4}(\:[0-9a-fA-F]{1,4}){7}';

  return preg_match("/^$user@($domain|(\[($ipv4|$ipv6)\]))$/", $mail);
}

Drupal one look's pretty solid to me. The other 2 here should work for 99% of email addresses .... problem is with these, is the allowed domain for names etc keep changing so I guess these will always be changes. I am currently using the first one BTW.

Anyone know if there are built in functions in perl and php for doing this?

Please post any good email validation expressions you have .... not like the 6.2K one though .

Reference
http://www.regular-expressions.info/email.html
http://www.sitepoint.com/print/regular-expressions-php

[gwyneth]

There may be something on this site:

Regular Expression Library

People working with regular expressions may find this very useful:

Regular Expressions Cheat Sheet - Cheat Sheets

This appears to be a Firefox addon that I have in my collection, for some reason:

Regular Expressions Tester

[mp3]

This is one I use in a contact form script. I think I have a newer one somewhere....I should really find it as this was my first attempt at PHP's PCRE support.

Perhaps it will be useful though.

"/^[a-zA-Z]+[a-zA-Z0-9_-]* ((([.]{1}) | ([a-zA-Z0-9_-]*)) | (([+]{1}) | ([a-zA-Z0-9_-]*)) | (([.]{1}) ([a-zA-Z0-9_-]+) ([+]{1}) ([a-zA-Z0-9_-]*))) [a-zA-Z0-9_-]+ [@]{1} ([a-zA-Z0-9-]+ [.]{1}){1,4} [a-zA-Z]{2,6} $/x"

"/^(.){2,64} @{1} (.){4,255}/x"

"/^(.){7,75}/x"

Broken into pieces for readability.