Perl get a part of a string

Applications Programming
1

I need some help to divide an email address.
I need to grab the left part of the @. Maybe substr?
example:
john.smith@domain.com.br

I would need to grab just the username part...

my $user = "john.smith@domain.com.br";
if($user =~ s/@/\@/){
print "EMAIL: " .$user;
}
2 
$ perl -le'
$user = "john.smith\@domain.com.br"; 
print +(split "@", $user)[0]'
john.smith
3

uh.. i should have thought of spliting it!
thank you