Pattern matching email address using regular expressions

Question

Filter email address with regular expressions: I am new to regular expressions and was hoping someone might be able to help out.

I am trying to pattern match an email address string with the following format:

FirstName.LastName@gmail.com

I want to be sure that there is a period somewhere before the '@' character and that the characters after the '@' character matches gmail.com

Thanks, Brad

Answer 1

You want some symbols before and after the dot, so I would suggest .+\..+@gmail\.com.

.+ means any symbols (.) can appear 1 or more times (+)
\. means the dot symbol; screened with backslash to suppress the special meaning of .
@gmail and com should be matched exactly.

See also Regular Expression Basic Syntax Reference

EDIT: gmail rules for account name only allow latin letters, digits, and dots, so a better regex is
[a-zA-Z0-9]+\.[a-zA-Z0-9]+@gmail\.com

Answer 2

check valid email

^(?=[a-zA-Z0-9][a-zA-Z0-9@.-]{5,253})^(?!.*?[.]{2})[a-zA-Z0-9.-]+[a-zA-Z0-9_-]@(?=.?[.]{1})(?!.?[-]{2})[a-zA-Z0-9][a-zA-Z0-9.-]+(.[a-z]{2,}|.[0-9]{1,})$

enforced rules:

• must start with alphanumeric char
• can only have alphanumeric and @._- char and have no max than 253 char
• cannot have 2 consecutives .
• char before @ can only be alphanumeric and ._-
• most have @ in the middle
• need to have at least 1 . in the domain part
• cannot have double - in the domain part
• can only have alphanumeric and .- char in the domain part
• need to finish by a valid extension of 2 or more letters
• added support for ip (test@1.1.1.1)

Answer 3

You don't even need regex since your requirements are pretty specific. Not sure what language you're using, but most would support doing a split on @ and checking for a .. In python:

name, _, domain = email.partition('@')
if '.' in name and domain == 'gmail.com':
    # valid

Answer 4

You haven't tell us what kind of regex flavor you need however this example will fit most of them:

.*\..*@gmail.com

Answer 5

Assuming Unix style where . is any character: .*\..*@gmail\.com

Edit: escaped the . in the domain