From: Brian Candler <b.candler@...>
Date: 2010-11-07T00:34:46+09:00
Subject: Re: regular expression

Johnathan Smith wrote in post #616840:
> im looking to write a regular expression for an email address
> however, i want the first part of the name to be initials (first initial
> and optional middle initial) and a surname
>
> such as
>
> j.m.smith@domain.com

Is this a homework question?

Break the problem down. Write regexp expressions which match the 
individual bits:

* any letter followed by a dot
* a surname - say any sequence of one or more letters
* an @ sign
* a domain (depends how strict you want to be - maybe sufficient is to 
match letter, digit, dot or hyphen, one or more times)

and then combine them.

To match any letter, use a range: [a-z]
To match a literal dot, use \. (because . matches any character)
To match something 0 or 1 times, follow it by '?'
To match something 0 or more times, follow it by '*'
To match something 1 or more times, follow it by '+'
Use parentheses to make a group - e.g. the way to match the optional 
middle initial is
   (xxx)?
where xxx is whatever regexp you chose to match a letter followed by a 
dot

HTH, but if it doesn't, find a good regexp primer.

Regards,

Brian.

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