email checking function

[epidemic]

I made a email checking function but after i get the message: Email accepted it seems to crash 3 times ( the program) what am i doing wrong?

std::string GetValidEmail ()
{
  std::string email;
  std::cout <<"Your Email address:";
  std::getline (std::cin,email);
  std::string::size_type checkPoint = email.find( ".", 0 );
  std::string::size_type checkAt    = email.find( "@", 0 );

  while ( checkPoint == std::string::npos || checkPoint == std::string::npos || email.length() >= 50)
  {
    std::cout <<"Your email is either Too long(max 50 chars) or Invalid.\n"
              <<"Please input an shorter or valid email adress." << std::endl;

    std::getline (std::cin,email);
    checkPoint = email.find( ".", 0 );
    checkAt    = email.find( "@", 0 );
  }
  std::cout <<"Email Accepted" << std::endl;
}

and another question : how can i make my email checking function even better? maby implement some kind of list of known emailaddreshosters?

and if u might need it lol:

int main ()
{
  std::string kaka;
  kaka = GetValidEmail ();
  std::cout << kaka << std::endl;


}

[epidemic]

Just found out the error, it did not return annything (the function) forgot to :

return (email);

but i could still use some help thinking of ways to make my email function better!

[l2u]

Maybe you should consider using boost regex to check mail address.

[epidemic]

and what is that supposted to be? :P

[dwks]

google("boost regex")[0] = http://www.boost.org/libs/regex/doc/index.html

It's a regular expression engine. You can tell it to look for

[\w\d]+@[\w\d\.]+*\.[\w\d]+

and it will match "[email protected]" but not "@bar.com" or "foo@bar" etc. My RE isn't perfect, though; it matches "[email protected]" as valid. It's also Perl-style regular expressions so I have no idea if it works with boost::regex.

[l2u]

Ok, here is the regular expression you can use with boost for email matching.

string email_expr = "^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$";