Poor man's email address validation function
I am pretty new to Perl. I already love it!
I needed to validate what a human operator states it is his email address, and I needed to avoid module installation. I have been tuning this function for a while and it seems to be quite good both in picking out bad formed addresses and in giving very few false positives.
I hope it can be useful to someone. I would thank those who can suggest improvements too.
sub es_email_mal_formado {
my $x = $_[0];
if ($x =~ m/[^\w\@\.\-]/) {return "Incluye un carácter prohibido"};
if ($x =~ m/\W\W/) {return "Tiene dos no alfanuméricos seguidos"};
if ($x =~ m/\@.+\@/) {return "Tiene más de una arroba"};
if (! ($x =~ m/\w\@\w/)) {return "No tiene arroba precedida y seguida de alfanumérico"};
if (! ($x =~ m/\w\.\w/)) {return "No tiene punto precedido y seguido de alfanumérico"};
if (! ($x =~ m/\@.+\./)) {return "No tiene punto en la parte que sigue a la arroba"};
if ($x =~ m/^\W/) {return "Empieza en no alfanumérico"};
if (! ($x =~ m/\.\w{2,4}$/)) {return "No tiene \"de 2 a 4 alfanuméricos\" al final"};
if ($x =~ m/(\@|\.).\.\w+$/) {return "Tiene una sola letra antes del último punto"};
return 0;
}
Re: Poor man's email address validation function
created: 2004-06-26 18:56:19
Some code based upon code from [cpan://Email::Valid::Loose] ...
my $esc = '\\\\'; my $period = '\.'; my $space = '\040'; my $open_br = '\['; my $close_br = '\]'; my $nonASCII = '\x80-\xff'; my $ctrl = '\000-\037'; my $cr_list = '\n\015'; my $qtext = qq/[^$esc$nonASCII$cr_list\"]/; # " my $dtext = qq/[^$esc$nonASCII$cr_list$open_br$close_br]/; my $quoted_pair = qq<$esc>.qq<[^$nonASCII]>; my $atom_char = qq/[^($space)<>\@,;:\".$esc$open_br$close_br$ctrl$nonASCII]/; my $atom = qq<$atom_char+(?!$atom_char)>; my $quoted_str = qq<\"$qtext*(?:$quoted_pair$qtext*)*\">; my $word = qq<(?:$atom|$quoted_str)>; my $domain_ref = $atom; my $domain_lit = qq<$open_br(?:$dtext|$quoted_pair)*$close_br>; my $sub_domain = qq<(?:$domain_ref|$domain_lit)>; my $domain = qq<$sub_domain(?:$period$sub_domain)*>; my $local_part = qq<$word(?:$word|$period)*>; my $Addr_spec_re = qr<$local_part\@$domain>; # Is an address valid? if ( $address =~ /^$Addr_spec_re$/o ) { # Yes } else { # No }
perl -le "print unpack'N', pack'B32', '00000000000000000000001011100110'"
•Re: Poor man's email address validation function
created: 2004-06-26 21:47:07
That's utterly and completely wrong with respect to "forbidden characters". For example, it invalidates any email address that has a gatewayed "local part" that contains a foreign (non RFC822) address, or addresses that I use to keep mail from getting scraped. For example, my fund responder is no longer fund@stonehenge.com, but fund*@stonehenge.com, and you've just ruled that address out.
-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.
Re^2: Poor man's email address validation function
created: 2004-06-27 05:56:55
Thanks Randal for your comments. Can you show me an example of an email address that has a gatewayed local part that contains a foreign (non RFC822) address? I just cannot figure out what that looks like.
Re^3: Poor man's email address validation function
created: 2004-06-28 06:20:37
fund*@stonehenge.com