fully RFC5321- and 5322-compatible PHP PCRE regex - php

Question

I'm trying to create a PHP PCRE regex that is (almost) fully compatible with RFC5321 and 5322 to test email addresses. The only thing I don't require is the (comment) part. I've seen some other attempts at this posted on here, but when I run tests vs. them they don't all work.
I have been working on one that is very close:
^(([\w \!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~\.]{1,64})|("[\w \!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~\.]{1,64}"))#(([\w\-]*\.?[\w\-]*)|(\[\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}\])|(\[IPv6:[\da-fA-F]{0,4}:[\da-fA-F]{0,4}:[\da-fA-F]{0,4}:[\da-fA-F]{0,4}\]))$
To break it down:
Local part:
(
Match at most 64 of the allowed characters
([\w \!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~\.]{1,64})
|
OR match the same set of characters in a quoted string:
("[\w \!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~\.]{1,64}")
)
end local part.
match # sign
#
match domain part:
(
match domain part using allowed characters:
([\w\-]*\.?[\w\-]*)
or ipv4 (it doesn't check to make sure they are < 255 - that would be handled elsewhere)
(\[\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}\])
or ipv6
(\[IPv6:[\da-fA-F]{0,4}:[\da-fA-F]{0,4}:[\da-fA-F]{0,4}:[\da-fA-F]{0,4}\])
)
The only thing it's missing is the ability to check for multiple consecutive .'s (periods) that are outside a quoted local-part. I ran tests on regex101.com vs. all the addresses below using some of my own tests and the tests on the wikipedia article about email addresses:
bob#smith.com
bob.smith#smith.com
bob-smith#smith.com
bob-smith#bob-smith.com
b0b!-...smith#smith.com <-DOES NOT VALIDATE CORRECTLY - MULTIPLE .'s
bob&smith#smith.com
"bob..smith"#smith.com
simple#example.com
very.common#example.com
disposable.style.email.with+symbol#example.com
other.email-with-hyphen#example.com
fully-qualified-domain#example.com
user.name+tag+sorting#example.com
x#example.com
example-indeed#strange-example.com
admin#mailserver1
example#s.example
" "#example.org
"john..doe"#example.org
Abc.example.com
A#b#c#example.com
a"b(c)d,e:f;g<h>i[j\k]l#example.com
just"not"right#example.com
this is"not\allowed#example.com
this\ still\"not\\allowed#example.com
1234567890123456789012345678901234567890123456789012345678901234+x#example.com
john..doe#example.com <-DOES NOT VALIDATE CORRECTLY - MULTIPLE .'s
john.doe#example..com
I attempted to use lookahead and lookbehind assertions to test for the consecutive periods, but I couldn't figure it out. I think that's the only thing it's missing (other than the comments, which for my purposes aren't required).
Is there a way to check for the periods that wouldn't alter what I currently have too much, or would it require a different approach?
Please let me know if I missed anything else.
Thank you.

Answer 1

You may add (?!("[^"]*"|[^"])*\.{2}) after ^.
See the regex demo.
The (?!("[^"]*"|[^"])*\.{2}) negative lookahead fails the match if, immediately to the right of the current location, there is
("[^"]*"|[^"])* - 0 or more occurrences of a " followed with 0+ chars other than " and then " or any char other than "
\.{2} - two consecutive dots.

Answer 2

I would recommend you read this. Suffice it to say that writing a regex that will work 100% is impossible.
I've written a non-Regex implementation here. If you port this to php and file an issue on my github page or send me an email (listed on my github page), I will happily link to it.
As you can tell from the unit tests, it's comprehensive enough to work with EAI addresses as well.