require 5.006;
use strict;
use warnings;
package Email::Valid;
$Email::Valid::VERSION = '1.200';
# ABSTRACT: Check validity of Internet email addresses
our (
  $RFC822PAT,
  $Details, $Resolver, $Nslookup_Path,
  $Debug,
);

use Carp;
use IO::File;
use Mail::Address;
use File::Spec;
use Scalar::Util 'blessed';

our %AUTOLOAD = (
  allow_ip => 1,
  fqdn     => 1,
  fudge    => 1,
  mxcheck  => 1,
  tldcheck => 1,
  local_rules => 1,
  localpart => 1,
);

our $NSLOOKUP_PAT = 'preference|serial|expire|mail\s+exchanger';
our @NSLOOKUP_PATHS = File::Spec->path();

# initialize if already loaded, better in prefork mod_perl environment
our $DNS_Method = defined $Net::DNS::VERSION ? 'Net::DNS' : '';
unless ($DNS_Method) {
    __PACKAGE__->_select_dns_method;
}

# initialize $Resolver if necessary
if ($DNS_Method eq 'Net::DNS') {
    unless (defined $Resolver) {
        $Resolver = Net::DNS::Resolver->new;
    }
}

sub new {
  my $class   = shift;

  $class = ref $class || $class;
  bless my $self = {}, $class;
  $self->_initialize;
  %$self = $self->_rearrange([ keys %AUTOLOAD ], \@_);
  return $self;
}

sub _initialize {
  my $self = shift;

  $self->{mxcheck}     = 0;
  $self->{tldcheck}    = 0;
  $self->{fudge}       = 0;
  $self->{fqdn}        = 1;
  $self->{allow_ip}    = 1;
  $self->{local_rules} = 0;
  $self->{localpart}   = 1;
  $self->{details}     = $Details = undef;
}

# Pupose: handles named parameter calling style
sub _rearrange {
  my $self = shift;
  my(@names)  = @{ shift() };
  my(@params) = @{ shift() };
  my(%args);

  ref $self ? %args = %$self : _initialize( \%args );
  return %args unless @params;

  unless (@params > 1 and $params[0] =~ /^-/) {
    while(@params) {
      croak 'unexpected number of parameters' unless @names;
      $args{ lc shift @names } = shift @params;
    }
    return %args;
  }

  while(@params) {
    my $param = lc substr(shift @params, 1);
    $args{ $param } = shift @params;
  }

  %args;
}

# Purpose: determine why an address failed a check
sub details {
  my $self = shift;

  return (ref $self ? $self->{details} : $Details) unless @_;
  $Details = shift;
  $self->{details} = $Details if ref $self;
  return undef;
}

# Purpose: Check whether address conforms to RFC 822 syntax.
sub rfc822 {
  my $self = shift;
  my %args = $self->_rearrange([qw( address )], \@_);

  my $addr = $args{address} or return $self->details('rfc822');
  $addr = $addr->address if (blessed($addr) && $addr->isa('Mail::Address'));

  return $self->details('rfc822')
    if $addr =~ /\P{ASCII}/ or $addr !~ m/^$RFC822PAT$/o;

  return 1;
}

# Purpose: attempt to locate the nslookup utility
sub _find_nslookup {
  my $self = shift;

  my $ns = 'nslookup';
  foreach my $path (@NSLOOKUP_PATHS) {
    my $file = File::Spec->catfile($path, $ns);
    return "$file.exe" if ($^O eq 'MSWin32') and -x "$file.exe" and !-d _;
    return $file if -x $file and !-d _;
  }
  return undef;
}

sub _select_dns_method {
  # Configure a global resolver object for DNS queries
  # if Net::DNS is available
  eval { require Net::DNS };
  return $DNS_Method = 'Net::DNS' unless $@;

  $DNS_Method = 'nslookup';
}

# Purpose: perform DNS query using the Net::DNS module
sub _net_dns_query {
  my $self = shift;
  my $host = shift;

  $Resolver = Net::DNS::Resolver->new unless defined $Resolver;

  my @mx_entries = Net::DNS::mx($Resolver, $host);

  if (@mx_entries) {
    foreach my $mx (@mx_entries) {
      my $mxhost = $mx->exchange;
      my $query  = $Resolver->search($mxhost);
      next unless ($query);
      foreach my $a_rr ($query->answer) {
        return 1 unless $a_rr->type ne 'A';
      }
    }
  }

  return $self->details('mx');
}

# Purpose: perform DNS query using the nslookup utility
sub _nslookup_query {
  my $self = shift;
  my $host = shift;
  local($/, *OLDERR);

  unless ($Nslookup_Path) {
    $Nslookup_Path = $self->_find_nslookup
      or croak 'unable to locate nslookup';
  }

  # Check for an A record
  return 1 if gethostbyname $host;

  # Check for an MX record
  if ($^O eq 'MSWin32' or $^O eq 'Cygwin') {
    # Oh no, we're on Windows!
    require IO::CaptureOutput;
    my $response = IO::CaptureOutput::capture_exec(
     $Nslookup_Path, '-query=mx', $host
    );
    croak "unable to execute nslookup '$Nslookup_Path': exit $?" if $?;
    print STDERR $response if $Debug;
    $response =~ /$NSLOOKUP_PAT/io or return $self->details('mx');
    return 1;
  } else {
    # phew, we're not on Windows!
    if (my $fh = IO::File->new('-|')) {
      my $response = <$fh>;
      print STDERR $response if $Debug;
      close $fh;
      $response =~ /$NSLOOKUP_PAT/io or return $self->details('mx');
      return 1;
    } else {
      open OLDERR, '>&STDERR' or croak "cannot dup stderr: $!";
      open STDERR, '>&STDOUT' or croak "cannot redirect stderr to stdout: $!";
      {
        exec $Nslookup_Path, '-query=mx', $host;
      }
      open STDERR, ">&OLDERR";
      croak "unable to execute nslookup '$Nslookup_Path': $!";
    }
  }
}

# Purpose: Check whether a top level domain is valid for a domain.
sub tld {
  my $self = shift;
  my %args = $self->_rearrange([qw( address )], \@_);

  unless (eval {require Net::Domain::TLD; Net::Domain::TLD->VERSION(1.65); 1}) {
    die "Net::Domain::TLD not available";
  }

  my $host = $self->_host( $args{address} or return $self->details('tld') );
  my ($tld) = $host =~ m#\.(\w+)$#;

  my %invalid_tlds = map { $_ => 1 } qw(invalid test example localhost);

  return defined $invalid_tlds{$tld} ? 0 : Net::Domain::TLD::tld_exists($tld);
}

# Purpose: Check whether a DNS record (A or MX) exists for a domain.
sub mx {
  my $self = shift;
  my %args = $self->_rearrange([qw( address )], \@_);

  my $host = $self->_host($args{address}) or return $self->details('mx');

  $self->_select_dns_method unless $DNS_Method;

  if ($DNS_Method eq 'Net::DNS') {
    print STDERR "using Net::DNS for dns query\n" if $Debug;
    return $self->_net_dns_query( $host );
  } elsif ($DNS_Method eq 'nslookup') {
    print STDERR "using nslookup for dns query\n" if $Debug;
    return $self->_nslookup_query( $host );
  } else {
    croak "unknown DNS method '$DNS_Method'";
  }
}

# Purpose: convert address to host
# Returns: host

sub _host {
  my $self = shift;
  my $addr = shift;

  $addr = $addr->address if (blessed($addr) && $addr->isa('Mail::Address'));

  my $host = ($addr =~ /^.*@(.*)$/ ? $1 : $addr);
  $host =~ s/\s+//g;

  # REMOVE BRACKETS IF IT'S A DOMAIN-LITERAL
  #   RFC822 3.4.6
  #   Square brackets ("[" and "]") are used to indicate the
  #   presence of a domain-literal, which the appropriate
  #   name-domain is to use directly, bypassing normal
  #   name-resolution mechanisms.
  $host =~ s/(^\[)|(\]$)//g;
  $host;
}

# Purpose: Fix common addressing errors
# Returns: Possibly modified address
sub _fudge {
  my $self = shift;
  my $addr = shift;

  $addr =~ s/\s+//g if $addr =~ /aol\.com$/i;
  $addr =~ s/,/./g  if $addr =~ /compuserve\.com$/i;
  $addr;
}

# Purpose: Special address restrictions on a per-domain basis.
# Caveats: These organizations may change their rules at any time.
sub _local_rules {
  my $self = shift;
  my($user, $host) = @_;

  1;
}

sub _valid_local_part {
  my ($self, $localpart) = @_;

  return 0 unless defined $localpart and length $localpart <= 64;

  return 1;
}

sub _valid_domain_parts {
  my ($self, $string) = @_;

  return unless $string and length $string <= 255;
  return if $string =~ /\.\./;
  my @labels = split /\./, $string;

  for my $label (@labels) {
    return 0 unless $self->_is_domain_label($label);
  }
  return scalar @labels;
}

sub _is_domain_label {
  my ($self, $string) = @_;
  return unless $string =~ /\A
    [A-Z0-9]          # must start with an alnum
    (?:
      [-A-Z0-9]*      # then maybe a dash or alnum
      [A-Z0-9]        # finally ending with an alnum
    )?                # lather, rinse, repeat
  \z/ix;
  return 1;
}

# Purpose: Put an address through a series of checks to determine
#          whether it should be considered valid.
sub address {
  my $self = shift;
  my %args = $self->_rearrange([qw( address fudge mxcheck tldcheck fqdn
                                    local_rules )], \@_);

  my $addr = $args{address} or return $self->details('rfc822');
  $addr = $addr->address if (blessed($addr) && $addr->isa('Mail::Address'));

  $addr = $self->_fudge( $addr ) if $args{fudge};
  $self->rfc822( -address => $addr ) or return undef;

  ($addr) = Mail::Address->parse( $addr );

  $addr or return $self->details('rfc822'); # This should never happen

  if (length($addr->address) > 254) {
    return $self->details('address_too_long');
  }

  if ($args{local_rules}) {
    $self->_local_rules( $addr->user, $addr->host )
      or return $self->details('local_rules');
  }

  if ($args{localpart}) {
    $self->_valid_local_part($addr->user) > 0
      or return $self->details('localpart');
  }

  my $ip_ok = $args{allow_ip} && $addr->host =~ /\A\[
    (?:[0-9]{1,3}\.){3}[0-9]{1,3}
  /x;

  if (! $ip_ok && $args{fqdn}) {
    my $domain_parts = $self->_valid_domain_parts($addr->host);

    return $self->details('fqdn')
      unless $ip_ok || ($domain_parts && $domain_parts > 1);
  }

  if (! $ip_ok && $args{tldcheck}) {
    $self->tld( $addr->host ) or return $self->details('tldcheck');
  }

  if ($args{mxcheck}) {
    # I'm not sure this ->details call is needed, but I'll test for it later.
    # The whole ->details thing is... weird. -- rjbs, 2006-06-08
    $self->mx( $addr->host ) or return $self->details('mxcheck');
  }

  return (wantarray ? ($addr->address, $addr) : $addr->address);
}

sub AUTOLOAD {
  my $self = shift;
  my $type = ref($self) || die "$self is not an object";
  my $name = our $AUTOLOAD;

  $name =~ s/.*://;
  return if $name eq 'DESTROY';
  die "unknown autoload name '$name'" unless $AUTOLOAD{$name};

  return (@_ ? $self->{$name} = shift : $self->{$name});
}

# Regular expression built using Jeffrey Friedl's example in
# _Mastering Regular Expressions_ (http://www.ora.com/catalog/regexp/).

$RFC822PAT = <<'EOF';
[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\
xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xf
f\n\015()]*)*\)[\040\t]*)*(?:(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\x
ff]+(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff])|"[^\\\x80-\xff\n\015
"]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015"]*)*")[\040\t]*(?:\([^\\\x80-\
xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80
-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*
)*(?:\.[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\
\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\
x80-\xff\n\015()]*)*\)[\040\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x8
0-\xff]+(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff])|"[^\\\x80-\xff\n
\015"]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015"]*)*")[\040\t]*(?:\([^\\\x
80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^
\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040
\t]*)*)*@[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([
^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\
\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\
x80-\xff]+(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-
\xff\n\015\[\]]|\\[^\x80-\xff])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()
]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\
x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:\.[\04
0\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\
n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\
015()]*)*\)[\040\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?!
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\
]]|\\[^\x80-\xff])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\
x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\01
5()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*)*|(?:[^(\040)<>@,;:".
\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]
)|"[^\\\x80-\xff\n\015"]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015"]*)*")[^
()<>@,;:".\\\[\]\x80-\xff\000-\010\012-\037]*(?:(?:\([^\\\x80-\xff\n\0
15()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][
^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)|"[^\\\x80-\xff\
n\015"]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015"]*)*")[^()<>@,;:".\\\[\]\
x80-\xff\000-\010\012-\037]*)*<[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?
:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-
\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:@[\040\t]*
(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015
()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()
]*)*\)[\040\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\0
40)<>@,;:".\\\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|\\
[^\x80-\xff])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\
xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*
)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:\.[\040\t]*(?:\([^\\\x80
-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x
80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t
]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\
\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|\\[^\x80-\xff])
*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x
80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80
-\xff\n\015()]*)*\)[\040\t]*)*)*(?:,[\040\t]*(?:\([^\\\x80-\xff\n\015(
)]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\
\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*@[\040\t
]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\0
15()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015
()]*)*\)[\040\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(
\040)<>@,;:".\\\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|
\\[^\x80-\xff])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80
-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()
]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:\.[\040\t]*(?:\([^\\\x
80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^
\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040
\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".
\\\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|\\[^\x80-\xff
])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\
\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x
80-\xff\n\015()]*)*\)[\040\t]*)*)*)*:[\040\t]*(?:\([^\\\x80-\xff\n\015
()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\
\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*)?(?:[^
(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\\[\]\000-
\037\x80-\xff])|"[^\\\x80-\xff\n\015"]*(?:\\[^\x80-\xff][^\\\x80-\xff\
n\015"]*)*")[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|
\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))
[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:\.[\040\t]*(?:\([^\\\x80-\xff
\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\x
ff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(
?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\\[\]\
000-\037\x80-\xff])|"[^\\\x80-\xff\n\015"]*(?:\\[^\x80-\xff][^\\\x80-\
xff\n\015"]*)*")[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\x
ff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)
*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*)*@[\040\t]*(?:\([^\\\x80-\x
ff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-
\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)
*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\\[\
]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|\\[^\x80-\xff])*\]
)[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-
\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\x
ff\n\015()]*)*\)[\040\t]*)*(?:\.[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(
?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80
-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:[^(\040)<
>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\\[\]\000-\037\x8
0-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|\\[^\x80-\xff])*\])[\040\t]*(?:
\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]
*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)
*\)[\040\t]*)*)*>)
EOF

$RFC822PAT =~ s/\n//g;

1;


#pod =head1 SYNOPSIS
#pod
#pod   use Email::Valid;
#pod   my $address = Email::Valid->address('maurice@hevanet.com');
#pod   print ($address ? 'yes' : 'no');
#pod
#pod =head1 DESCRIPTION
#pod
#pod This module determines whether an email address is well-formed, and
#pod optionally, whether a mail host exists for the domain.
#pod
#pod Please note that there is no way to determine whether an
#pod address is deliverable without attempting delivery
#pod (for details, see L<perlfaq 9|http://perldoc.perl.org/perlfaq9.html#How-do-I-check-a-valid-mail-address>).
#pod
#pod =head1 PREREQUISITES
#pod
#pod This module requires perl 5.004 or later and the L<Mail::Address> module.
#pod Either the L<Net::DNS> module or the nslookup utility is required
#pod for DNS checks.  The L<Net::Domain::TLD> module is required to check the
#pod validity of top level domains.
#pod
#pod =head1 METHODS
#pod
#pod Every method which accepts an C<< <ADDRESS> >> parameter may
#pod be passed either a string or an instance of the Mail::Address
#pod class.  All errors raise an exception.
#pod
#pod =over 4
#pod
#pod =item new ( [PARAMS] )
#pod
#pod This method is used to construct an Email::Valid object.
#pod It accepts an optional list of named parameters to
#pod control the behavior of the object at instantiation.
#pod
#pod The following named parameters are allowed.  See the
#pod individual methods below for details.
#pod
#pod  -mxcheck
#pod  -tldcheck
#pod  -fudge
#pod  -fqdn
#pod  -allow_ip
#pod  -local_rules
#pod
#pod =item mx ( <ADDRESS>|<DOMAIN> )
#pod
#pod This method accepts an email address or domain name and determines
#pod whether a DNS record (A or MX) exists for it.
#pod
#pod The method returns true if a record is found and undef if not.
#pod
#pod Either the Net::DNS module or the nslookup utility is required for
#pod DNS checks.  Using Net::DNS is the preferred method since error
#pod handling is improved.  If Net::DNS is available, you can modify
#pod the behavior of the resolver (e.g. change the default tcp_timeout
#pod value) by manipulating the global L<Net::DNS::Resolver> instance stored in
#pod C<$Email::Valid::Resolver>.
#pod
#pod =item rfc822 ( <ADDRESS> )
#pod
#pod This method determines whether an address conforms to the RFC822
#pod specification (except for nested comments).  It returns true if it
#pod conforms and undef if not.
#pod
#pod =item fudge ( <TRUE>|<FALSE> )
#pod
#pod Specifies whether calls to address() should attempt to correct
#pod common addressing errors.  Currently, this results in the removal of
#pod spaces in AOL addresses, and the conversion of commas to periods in
#pod Compuserve addresses.  The default is false.
#pod
#pod =item allow_ip ( <TRUE>|<FALSE> )
#pod
#pod Specifies whether a "domain literal" is acceptable as the domain part.  That
#pod means addresses like:  C<rjbs@[1.2.3.4]>
#pod
#pod The checking for the domain literal is stricter than the RFC and looser than
#pod checking for a valid IP address, I<but this is subject to change>.
#pod
#pod The default is true.
#pod
#pod =item fqdn ( <TRUE>|<FALSE> )
#pod
#pod Specifies whether addresses passed to address() must contain a fully
#pod qualified domain name (FQDN).  The default is true.
#pod
#pod B<Please note!>  FQDN checks only occur for non-domain-literals.  In other
#pod words, if you have set C<allow_ip> and the address ends in a bracketed IP
#pod address, the FQDN check will not occur.
#pod
#pod =item tld ( <ADDRESS> )
#pod
#pod This method determines whether the domain part of an address is in a
#pod recognized top-level domain.
#pod
#pod B<Please note!>  TLD checks only occur for non-domain-literals.  In other
#pod words, if you have set C<allow_ip> and the address ends in a bracketed IP
#pod address, the TLD check will not occur.
#pod
#pod =item local_rules ( <TRUE>|<FALSE> )
#pod
#pod Specifies whether addresses passed to address() should be tested
#pod for domain specific restrictions.  Currently, this is limited to
#pod certain AOL restrictions that I'm aware of.  The default is false.
#pod
#pod =item mxcheck ( <TRUE>|<FALSE> )
#pod
#pod Specifies whether addresses passed to address() should be checked
#pod for a valid DNS entry.  The default is false.
#pod
#pod =item tldcheck ( <TRUE>|<FALSE> )
#pod
#pod Specifies whether addresses passed to address() should be checked
#pod for a valid top level domains.  The default is false.
#pod
#pod =item address ( <ADDRESS> )
#pod
#pod This is the primary method which determines whether an email
#pod address is valid.  Its behavior is modified by the values of
#pod mxcheck(), tldcheck(), local_rules(), fqdn(), and fudge().  If the address
#pod passes all checks, the (possibly modified) address is returned as
#pod a string.  Otherwise, undef is returned.
#pod In a list context, the method also returns an instance of the
#pod Mail::Address class representing the email address.
#pod
#pod =item details ()
#pod
#pod If the last call to address() returned undef, you can call this
#pod method to determine why it failed.  Possible values are:
#pod
#pod  rfc822
#pod  localpart
#pod  local_rules
#pod  fqdn
#pod  mxcheck
#pod  tldcheck
#pod
#pod If the class is not instantiated, you can get the same information
#pod from the global C<$Email::Valid::Details>.
#pod
#pod =back
#pod
#pod =head1 EXAMPLES
#pod
#pod Let's see if the address 'maurice@hevanet.com' conforms to the
#pod RFC822 specification:
#pod
#pod   print (Email::Valid->address('maurice@hevanet.com') ? 'yes' : 'no');
#pod
#pod Additionally, let's make sure there's a mail host for it:
#pod
#pod   print (Email::Valid->address( -address => 'maurice@hevanet.com',
#pod                                 -mxcheck => 1 ) ? 'yes' : 'no');
#pod
#pod Let's see an example of how the address may be modified:
#pod
#pod   $addr = Email::Valid->address('Alfred Neuman <Neuman @ foo.bar>');
#pod   print "$addr\n"; # prints Neuman@foo.bar
#pod
#pod Now let's add the check for top level domains:
#pod
#pod   $addr = Email::Valid->address( -address => 'Neuman@foo.bar',
#pod                                  -tldcheck => 1 );
#pod   print "$addr\n"; # doesn't print anything
#pod
#pod Need to determine why an address failed?
#pod
#pod   unless(Email::Valid->address('maurice@hevanet')) {
#pod     print "address failed $Email::Valid::Details check.\n";
#pod   }
#pod
#pod If an error is encountered, an exception is raised.  This is really
#pod only possible when performing DNS queries.  Trap any exceptions by
#pod wrapping the call in an eval block:
#pod
#pod   eval {
#pod     $addr = Email::Valid->address( -address => 'maurice@hevanet.com',
#pod                                    -mxcheck => 1 );
#pod   };
#pod   warn "an error was encountered: $@" if $@;
#pod
#pod =head1 CREDITS
#pod
#pod Significant portions of this module are based on the ckaddr program
#pod written by Tom Christiansen and the RFC822 address pattern developed
#pod by Jeffrey Friedl.  Neither were involved in the construction of this
#pod module; all errors are mine.
#pod
#pod Thanks very much to the following people for their suggestions and
#pod bug fixes:
#pod
#pod   Otis Gospodnetic <otis@DOMINIS.com>
#pod   Kim Ryan <kimaryan@ozemail.com.au>
#pod   Pete Ehlke <pde@listserv.music.sony.com>
#pod   Lupe Christoph
#pod   David Birnbaum
#pod   Achim
#pod   Elizabeth Mattijsen (liz@dijkmat.nl)
#pod
#pod =head1 SEE ALSO
#pod
#pod L<Mail::Address>, L<Net::DNS>, L<Net::Domain::TLD>, L<perlfaq9|https://metacpan.org/pod/distribution/perlfaq/lib/perlfaq9.pod>
#pod
#pod L<RFC822|https://www.ietf.org/rfc/rfc0822.txt> -
#pod standard for the format of ARPA internet text messages.
#pod Superseded by L<RFC2822|https://www.ietf.org/rfc/rfc2822.txt>.
#pod
#pod =cut

__END__

=pod

=encoding UTF-8

=head1 NAME

Email::Valid - Check validity of Internet email addresses

=head1 VERSION

version 1.200

=head1 SYNOPSIS

  use Email::Valid;
  my $address = Email::Valid->address('maurice@hevanet.com');
  print ($address ? 'yes' : 'no');

=head1 DESCRIPTION

This module determines whether an email address is well-formed, and
optionally, whether a mail host exists for the domain.

Please note that there is no way to determine whether an
address is deliverable without attempting delivery
(for details, see L<perlfaq 9|http://perldoc.perl.org/perlfaq9.html#How-do-I-check-a-valid-mail-address>).

=head1 PREREQUISITES

This module requires perl 5.004 or later and the L<Mail::Address> module.
Either the L<Net::DNS> module or the nslookup utility is required
for DNS checks.  The L<Net::Domain::TLD> module is required to check the
validity of top level domains.

=head1 METHODS

Every method which accepts an C<< <ADDRESS> >> parameter may
be passed either a string or an instance of the Mail::Address
class.  All errors raise an exception.

=over 4

=item new ( [PARAMS] )

This method is used to construct an Email::Valid object.
It accepts an optional list of named parameters to
control the behavior of the object at instantiation.

The following named parameters are allowed.  See the
individual methods below for details.

 -mxcheck
 -tldcheck
 -fudge
 -fqdn
 -allow_ip
 -local_rules

=item mx ( <ADDRESS>|<DOMAIN> )

This method accepts an email address or domain name and determines
whether a DNS record (A or MX) exists for it.

The method returns true if a record is found and undef if not.

Either the Net::DNS module or the nslookup utility is required for
DNS checks.  Using Net::DNS is the preferred method since error
handling is improved.  If Net::DNS is available, you can modify
the behavior of the resolver (e.g. change the default tcp_timeout
value) by manipulating the global L<Net::DNS::Resolver> instance stored in
C<$Email::Valid::Resolver>.

=item rfc822 ( <ADDRESS> )

This method determines whether an address conforms to the RFC822
specification (except for nested comments).  It returns true if it
conforms and undef if not.

=item fudge ( <TRUE>|<FALSE> )

Specifies whether calls to address() should attempt to correct
common addressing errors.  Currently, this results in the removal of
spaces in AOL addresses, and the conversion of commas to periods in
Compuserve addresses.  The default is false.

=item allow_ip ( <TRUE>|<FALSE> )

Specifies whether a "domain literal" is acceptable as the domain part.  That
means addresses like:  C<rjbs@[1.2.3.4]>

The checking for the domain literal is stricter than the RFC and looser than
checking for a valid IP address, I<but this is subject to change>.

The default is true.

=item fqdn ( <TRUE>|<FALSE> )

Specifies whether addresses passed to address() must contain a fully
qualified domain name (FQDN).  The default is true.

B<Please note!>  FQDN checks only occur for non-domain-literals.  In other
words, if you have set C<allow_ip> and the address ends in a bracketed IP
address, the FQDN check will not occur.

=item tld ( <ADDRESS> )

This method determines whether the domain part of an address is in a
recognized top-level domain.

B<Please note!>  TLD checks only occur for non-domain-literals.  In other
words, if you have set C<allow_ip> and the address ends in a bracketed IP
address, the TLD check will not occur.

=item local_rules ( <TRUE>|<FALSE> )

Specifies whether addresses passed to address() should be tested
for domain specific restrictions.  Currently, this is limited to
certain AOL restrictions that I'm aware of.  The default is false.

=item mxcheck ( <TRUE>|<FALSE> )

Specifies whether addresses passed to address() should be checked
for a valid DNS entry.  The default is false.

=item tldcheck ( <TRUE>|<FALSE> )

Specifies whether addresses passed to address() should be checked
for a valid top level domains.  The default is false.

=item address ( <ADDRESS> )

This is the primary method which determines whether an email
address is valid.  Its behavior is modified by the values of
mxcheck(), tldcheck(), local_rules(), fqdn(), and fudge().  If the address
passes all checks, the (possibly modified) address is returned as
a string.  Otherwise, undef is returned.
In a list context, the method also returns an instance of the
Mail::Address class representing the email address.

=item details ()

If the last call to address() returned undef, you can call this
method to determine why it failed.  Possible values are:

 rfc822
 localpart
 local_rules
 fqdn
 mxcheck
 tldcheck

If the class is not instantiated, you can get the same information
from the global C<$Email::Valid::Details>.

=back

=head1 EXAMPLES

Let's see if the address 'maurice@hevanet.com' conforms to the
RFC822 specification:

  print (Email::Valid->address('maurice@hevanet.com') ? 'yes' : 'no');

Additionally, let's make sure there's a mail host for it:

  print (Email::Valid->address( -address => 'maurice@hevanet.com',
                                -mxcheck => 1 ) ? 'yes' : 'no');

Let's see an example of how the address may be modified:

  $addr = Email::Valid->address('Alfred Neuman <Neuman @ foo.bar>');
  print "$addr\n"; # prints Neuman@foo.bar

Now let's add the check for top level domains:

  $addr = Email::Valid->address( -address => 'Neuman@foo.bar',
                                 -tldcheck => 1 );
  print "$addr\n"; # doesn't print anything

Need to determine why an address failed?

  unless(Email::Valid->address('maurice@hevanet')) {
    print "address failed $Email::Valid::Details check.\n";
  }

If an error is encountered, an exception is raised.  This is really
only possible when performing DNS queries.  Trap any exceptions by
wrapping the call in an eval block:

  eval {
    $addr = Email::Valid->address( -address => 'maurice@hevanet.com',
                                   -mxcheck => 1 );
  };
  warn "an error was encountered: $@" if $@;

=head1 CREDITS

Significant portions of this module are based on the ckaddr program
written by Tom Christiansen and the RFC822 address pattern developed
by Jeffrey Friedl.  Neither were involved in the construction of this
module; all errors are mine.

Thanks very much to the following people for their suggestions and
bug fixes:

  Otis Gospodnetic <otis@DOMINIS.com>
  Kim Ryan <kimaryan@ozemail.com.au>
  Pete Ehlke <pde@listserv.music.sony.com>
  Lupe Christoph
  David Birnbaum
  Achim
  Elizabeth Mattijsen (liz@dijkmat.nl)

=head1 SEE ALSO

L<Mail::Address>, L<Net::DNS>, L<Net::Domain::TLD>, L<perlfaq9|https://metacpan.org/pod/distribution/perlfaq/lib/perlfaq9.pod>

L<RFC822|https://www.ietf.org/rfc/rfc0822.txt> -
standard for the format of ARPA internet text messages.
Superseded by L<RFC2822|https://www.ietf.org/rfc/rfc2822.txt>.

=head1 AUTHOR

Maurice Aubrey <maurice@hevanet.com>

=head1 CONTRIBUTORS

=for stopwords Alexandr Ciornii Karel Miko McA Michael Schout Mohammad S Anwar Neil Bowers Ricardo SIGNES Steve Bertrand Svetlana Troy Morehouse

=over 4

=item *

Alexandr Ciornii <alexchorny@gmail.com>

=item *

Karel Miko <karel.miko@gmail.com>

=item *

McA <McA@github.com>

=item *

Michael Schout <mschout@gkg.net>

=item *

Mohammad S Anwar <mohammad.anwar@yahoo.com>

=item *

Neil Bowers <neil@bowers.com>

=item *

Ricardo SIGNES <rjbs@cpan.org>

=item *

Steve Bertrand <steveb@cpan.org>

=item *

Svetlana <svetlana.wiczer@gmail.com>

=item *

Troy Morehouse <troymore@nbnet.nb.ca>

=back

=head1 COPYRIGHT AND LICENSE

This software is copyright (c) 1998 by Maurice Aubrey.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

=cut