Message/Field/MsgID.pm


=head1 NAME

Message::Field::MsgID --- Perl module for Message-ID
of Internet messages

=head1 DESCRIPTION

This module supports C<msg-id> defined by RFC 2822.
Message-ID generating algorithm suggested by
draft-ietf-usefor-msg-id-alt-00 is also supported.

=cut

package Message::Field::MsgID;
use strict;
use vars qw(@ISA %REG $VERSION);
$VERSION=do{my @r=(q$Revision: 1.5 $=~/\d+/g);sprintf "%d."."%02d" x $#r,@r};
require Message::Util;
require Message::Field::Structured;
push @ISA, qw(Message::Field::Structured);

use overload '""' => sub { $_[0]->stringify },
             fallback => 1;

*REG = \%Message::Util::REG;
## Inherited: comment, quoted_string, domain_literal
        ## WSP, FWS, phrase, NON_atom
        ## msg_id
        ## M_quoted_string

=head1 CONSTRUCTORS

The following methods construct new objects:

=over 4

=cut

## Initialize of this class -- called by constructors
sub _init ($;%) {
  my $self = shift;
  my %options = @_;
  my %DEFAULT = (
    -encoding_after_encode      => 'unknown-8bit',
    -encoding_before_decode     => 'unknown-8bit',
    #field_param_name
    #field_name
    #format
    -hash_name  => '%none',
    #hook_encode_string
    #hook_decode_string
    -software_name      => 'MFMpm',
    -software_name_hash => '%none',
    -validate   => 0,
  );
  $self->SUPER::_init (%DEFAULT, %options);
}

=item $m = Message::Field::MsgID->new ([%options])

Constructs a new object.  You might pass some options as parameters 
to the constructor.

=cut

sub new ($;%) {
  my $self = shift->SUPER::new (@_);
  my %option = @_;
  if ($option{id_left} && $option{id_right}) {
    $self->{id_left} = $option{id_left};
    $self->{id_right} = $option{id_right};
  } elsif ($option{addr_spec}
    || (($option{fqdn} || $option{ip_address} || $option{uucp})
        && ($option{login}))) {
    $self->_newid (\%option);
  }
  $self;
}

sub parse ($;$%) {
  my $class = shift;
  my $self = bless {}, $class;
  my $body = shift;  my @c;
  $self->_init (@_);
  ($body, @c) = $self->Message::Util::delete_comment_to_array ($body);
  
  $body = Message::Util::remove_wsp ($body);
  if ($body =~ /$REG{M_addr_spec}/) {
    my %s = &{$self->{option}->{hook_decode_string}} ($self,
              Message::Util::unquote_quoted_string ($1), type => 'quoted-string');
    $self->{id_left} = $s{value};
    #my %s = &{$self->{option}->{hook_decode_string}} ($self,
    #          Message::Util::unquote_if_domain_literal ($2), type => 'domain');
    #$self->{id_right} = $s{value};
    $self->{id_right} = $2;
  }
  
  $self;
}

sub _newid ($\%) {
  my $self = shift;
  my $o = shift;
  $$o{addr_spec} = Message::Util::remove_wsp ($$o{addr_spec});
  if ($$o{addr_spec} =~ /$REG{M_addr_spec}/) {
    $$o{login} = $1; $$o{fqdn} = $2;
  }
  if ($self->{option}->{validate} && $$o{fqdn} =~ 
     /[.@](example\.(?:com|org|net)|localdomain|localhost|example|invalid|arpa)$/) {
      Carp::croak "Msg-ID generation: invalid TLD of FQDN: .$1";
  }
  if (!$$o{fqdn} && $$o{ip_address}) {
    if ($self->{option}->{validate}
      && $$o{ip_address}=~/([0-9]+)\.([0-9]+)\.([0-9]+)\.([0-9]+)/){
      my ($c1, $c2, $c3, $c4) = ($1, $2, $3, $4);
      Carp::croak "Msg-ID generation: invalid IPv4 address: $c1.$c2.$c3.$c4"
        ## See [IANAREG] and draft-iana-special-ipv4
           if ($c1 == 0)        ## "this" network
           || ($c1 == 10)       ## private [RFC1918]
           || ($c1 == 127)      ## loopback
           || ($c1 == 169 && $c2 == 254)        ## "link local"
           || ($c1 == 172 && 16 <= $c2 && $c2 < 32)     ## private [RFC1918]
           || ($c1 == 192 && (($c2 == 0 && $c3 == 2)    ## "TEST-NET"
           || ($c2 == 88 && $c3 == 99)  ## 6to4 anycast [RFC3068]
           || ($c2 == 168)))    ## private [RFC1918]
           || ($c1 == 198 && ($c2 == 18 || $c2 == 19))  ## benchmark [RFC2544]
           || ($c1 >= 224);     ## class D,E [RFC3171]
    }
    $$o{fqdn} ||= '['.$$o{ip_address}.']';
  }
  if (!$$o{fqdn} && $$o{uucp}) {
    $$o{uucp} .= '.uucp' if $self->{option}->{validate} && $$o{uucp} !~ /\.uucp/i;
    $$o{fqdn} = $$o{uucp};
  }
  Carp::croak "Msg-ID generation: no FQDN"
    if $self->{option}->{validate} && !$$o{fqdn};
  
  $self->{id_right} = $$o{fqdn};
  
  Carp::croak "Msg-ID generation: no 'login'"
    if $self->{option}->{validate} && !$$o{login};
  $$o{login} = $self->_hash ($$o{login}, $self->{option}->{hash_name});
  
  my @s = ('0'..'9','a'..'z','-','=','_');
  my @t = ('0'..'9','a'..'z');
  my $unique = $t[rand @t].$s[rand @s].$s[rand @s].$s[rand @s].'.';
  $unique .= join ('.', $self->_base39 (time), $self->_base39 ($$), 
    $self->_hash ($self->{option}->{software_name},
                  $self->{option}->{software_name_hash}));
  $self->{id_left} = $unique
    .'%'.($self->{option}->{hash_name} ne '%none'? 
            $self->_hash ($self->{option}->{hash_name}, '%none') .'%': '')
    .$$o{login}
    .($$o{subject_changed}? '-_-': '');
  
  $self;
}

sub _hash ($$;$$) {
  my $self = shift;
  my ($str, $hash_name, $add_unsafe) = (shift, lc shift, shift);
  $add_unsafe ||= qr#[/.=\x09\x20]#;
  undef $hash_name if $hash_name eq '%none';
  if ($hash_name eq 'md5') {
    eval {require Digest::MD5} or Carp::croak "Msg-ID generation: $@";
    $str = Digest::MD5::md5_base64 ($str);
  } elsif ($hash_name eq 'sha1') {
    eval {require Digest::SHA1} or Carp::croak "Msg-ID generation: $@";
    $str = Digest::SHA1::sha1_base64 ($str);
  } elsif ($hash_name eq 'md2') {
    eval {require Digest::MD2} or Carp::croak "Msg-ID generation: $@";
    $str = Digest::MD2::md2_base64 ($str);
  } elsif ($hash_name eq 'crypt') {
    my @s = ('0'..'9','A'..'Z','a'..'z');
    my $salt = crypt('foobar', '$1$ab$') eq '$1$ab$uAP8qWqcFs3q.Gfl5PkL2.'?
      '$1$'.join('', map($s[rand @s], 1..8)).'$': $s[rand @s].$s[rand @s];
    $str = crypt ($str, $salt);
  }
  $str =~ s#($add_unsafe)#sprintf('=%02X', ord($1))#ge;
  $str =~ s/($REG{NON_atext_dot})/sprintf('=%02X', ord($1))/ge;
  $str;
}

sub _base39 ($$) {
  my $self = shift;
  my $number = shift;
  my @digit = ('0'..'9','a'..'z','-','=','_');
  my $ret = '';
  
  my ($rem);
  while ($number > 0) {
    $rem = $number % @digit;
    $ret = $digit[ $rem ].$ret;
    $number = ($number - $rem) / @digit;
  }
  $ret;
}

sub generate ($%) {
  my $self = shift;
  my %parameter = @_;
  for (grep {/^-/} keys %parameter) {$parameter{substr ($_, 1)} = $parameter{$_}}
  $self->_newid (\%parameter);
}

sub id_left ($) {
  my $self = shift;
  my %e = &{$self->{option}->{hook_encode_string}} ($self,
    $self->{id_left}, type => 'local-part');
  Message::Util::quote_unsafe_string ($e{value}, 
    unsafe_regex => qr/$REG{NON_atext_dot}|^\.|\.$/);
}
sub id_right ($) {
  my $self = shift;
  #my %e = &{$self->{option}->{hook_encode_string}} ($self,
  #  $self->{id_right}, type => 'domain');
  #Message::Util::quote_unsafe_domain ($e{value});
  Message::Util::quote_unsafe_domain ($self->{id_right});
}
sub content ($) {
  my $self = shift;
  my ($l, $r) = ($self->id_left, $self->id_right);
  sprintf '%s@%s', $l, $r if $l && $r;
}

sub stringify ($;%) {
  my $self = shift;
  my ($l, $r) = ($self->id_left, $self->id_right);
  sprintf '<%s@%s>', $l, $r if $l && $r;
}
*as_string = \&stringify;

=head1 EXAMPLE

  use Message::Field::MsgID;
  my $from = 'foo@bar.example';
  my $login = 'my-login-name';
  my $domain = 'foo.bar.example';
  my $ipv4 = '192.168.0.1';
  my %mid;
  $mid{no_crypt} = new Message::Field::MsgID 
    addr_spec => $from, -validate => 0;
  $mid{md5} = new Message::Field::MsgID
    login => $login, ip_address => $ipv4,
    -hash_name => 'md5', -validate => 0;
  $mid{sha1} = new Message::Field::MsgID
    login => $login, fqdn => $domain, subject_changed => 1,
    -hash_name => 'sha1', -validate => 0;
  for (keys %mid) {
    print $_, ":\t", $mid{$_}, "\n";
  }
  # sha1:   <t-9.bbxkfu.xsem.MFMMpm%sha1%9pnH2R6iN8KSIMby+dPU0i3M8RU-_-@foo.bar.example>
  # md5:    <7fu.bbxkfu.xsem.MFMMpm%md5%eBpd+12mupwxZBc6kMWR9g@[192.168.0.1]>
  # no_crypt:       <3vy.bbxkfu.xsem.MFMMpm%foo@bar.example>
  
  ## IMPORTANT NOTE: This example uses -validate option with
  ## '0' (does not validate) value since it uses example (invalid)
  ## resource names, such as 'foo.bar.example'.  Usually, this option
  ## shall not be used (and default value = '1' = does validate
  ## should be used).

=head1 SEE ALSO

RFC 822 E<lt>urn:ietf:rfc:822E<gt>, RFC 2822 E<lt>urn:ietf:rfc:2822E<gt>

RFC 850 E<lt>urn:ietf:rfc:850E<gt>, RFC 1036 E<lt>urn:ietf:rfc:1036E<gt>,
son-of-RFC1036, draft-ietf-usefor-article-06.txt
E<lt>urn:ietf:id:draft-ietf-usefor-article-06E<gt>

draft-ietf-usefor-message-id-01.txt
E<lt>urn:ietf:id:draft-ietf-usefor-message-id-01E<gt>

draft-ietf-usefor-msg-id-alt-00.txt
E<lt>urn:ietf:id:draft-ietf-usefor-msg-id-alt-00E<gt>

=head1 LICENSE

Copyright 2002 wakaba E<lt>w@suika.fam.cxE<gt>.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.

=head1 CHANGE

See F<ChangeLog>.
$Date: 2002/05/14 13:42:40 $

=cut

1;
1	wakaba	1.1
2			=head1 NAME
3
4	wakaba	1.4	Message::Field::MsgID --- Perl module for Message-ID
5			of Internet messages
6	wakaba	1.1
7			=head1 DESCRIPTION
8
9	wakaba	1.4	This module supports C<msg-id> defined by RFC 2822.
10			Message-ID generating algorithm suggested by
11			draft-ietf-usefor-msg-id-alt-00 is also supported.
12	wakaba	1.1
13			=cut
14
15			package Message::Field::MsgID;
16			use strict;
17	wakaba	1.4	use vars qw(@ISA %REG $VERSION);
18	wakaba	1.6	$VERSION=do{my @r=(q$Revision: 1.5 $=~/\d+/g);sprintf "%d."."%02d" x $#r,@r};
19	wakaba	1.4	require Message::Util;
20			require Message::Field::Structured;
21			push @ISA, qw(Message::Field::Structured);
22
23			use overload '""' => sub { $_[0]->stringify },
24			fallback => 1;
25
26			*REG = \%Message::Util::REG;
27			## Inherited: comment, quoted_string, domain_literal
28			## WSP, FWS, phrase, NON_atom
29			## msg_id
30			## M_quoted_string
31	wakaba	1.1
32	wakaba	1.4	=head1 CONSTRUCTORS
33	wakaba	1.1
34	wakaba	1.4	The following methods construct new objects:
35	wakaba	1.1
36	wakaba	1.4	=over 4
37	wakaba	1.1
38			=cut
39
40	wakaba	1.4	## Initialize of this class -- called by constructors
41			sub _init ($;%) {
42			my $self = shift;
43			my %options = @_;
44			my %DEFAULT = (
45			-encoding_after_encode => 'unknown-8bit',
46			-encoding_before_decode => 'unknown-8bit',
47			#field_param_name
48			#field_name
49			#format
50			-hash_name => '%none',
51			#hook_encode_string
52			#hook_decode_string
53			-software_name => 'MFMpm',
54			-software_name_hash => '%none',
55	wakaba	1.6	-validate => 0,
56	wakaba	1.4	);
57			$self->SUPER::_init (%DEFAULT, %options);
58	wakaba	1.1	}
59
60	wakaba	1.4	=item $m = Message::Field::MsgID->new ([%options])
61	wakaba	1.1
62	wakaba	1.4	Constructs a new object. You might pass some options as parameters
63			to the constructor.
64	wakaba	1.1
65			=cut
66
67	wakaba	1.4	sub new ($;%) {
68			my $self = shift->SUPER::new (@_);
69	wakaba	1.1	my %option = @_;
70	wakaba	1.4	if ($option{id_left} && $option{id_right}) {
71			$self->{id_left} = $option{id_left};
72			$self->{id_right} = $option{id_right};
73			} elsif ($option{addr_spec}
74			\|\| (($option{fqdn} \|\| $option{ip_address} \|\| $option{uucp})
75			&& ($option{login}))) {
76			$self->_newid (\%option);
77			}
78	wakaba	1.1	$self;
79			}
80
81	wakaba	1.4	sub parse ($;$%) {
82			my $class = shift;
83			my $self = bless {}, $class;
84	wakaba	1.6	my $body = shift; my @c;
85	wakaba	1.4	$self->_init (@_);
86	wakaba	1.6	($body, @c) = $self->Message::Util::delete_comment_to_array ($body);
87	wakaba	1.4
88			$body = Message::Util::remove_wsp ($body);
89			if ($body =~ /$REG{M_addr_spec}/) {
90			my %s = &{$self->{option}->{hook_decode_string}} ($self,
91			Message::Util::unquote_quoted_string ($1), type => 'quoted-string');
92			$self->{id_left} = $s{value};
93			#my %s = &{$self->{option}->{hook_decode_string}} ($self,
94			# Message::Util::unquote_if_domain_literal ($2), type => 'domain');
95			#$self->{id_right} = $s{value};
96			$self->{id_right} = $2;
97			}
98
99			$self;
100	wakaba	1.1	}
101
102	wakaba	1.4	sub _newid ($\%) {
103	wakaba	1.2	my $self = shift;
104	wakaba	1.4	my $o = shift;
105			$$o{addr_spec} = Message::Util::remove_wsp ($$o{addr_spec});
106			if ($$o{addr_spec} =~ /$REG{M_addr_spec}/) {
107			$$o{login} = $1; $$o{fqdn} = $2;
108			}
109			if ($self->{option}->{validate} && $$o{fqdn} =~
110	wakaba	1.5	/[.@](example\.(?:com\|org\|net)\|localdomain\|localhost\|example\|invalid\|arpa)$/) {
111	wakaba	1.4	Carp::croak "Msg-ID generation: invalid TLD of FQDN: .$1";
112			}
113			if (!$$o{fqdn} && $$o{ip_address}) {
114			if ($self->{option}->{validate}
115			&& $$o{ip_address}=~/([0-9]+)\.([0-9]+)\.([0-9]+)\.([0-9]+)/){
116			my ($c1, $c2, $c3, $c4) = ($1, $2, $3, $4);
117			Carp::croak "Msg-ID generation: invalid IPv4 address: $c1.$c2.$c3.$c4"
118			## See [IANAREG] and draft-iana-special-ipv4
119			if ($c1 == 0) ## "this" network
120			\|\| ($c1 == 10) ## private [RFC1918]
121			\|\| ($c1 == 127) ## loopback
122			\|\| ($c1 == 169 && $c2 == 254) ## "link local"
123			\|\| ($c1 == 172 && 16 <= $c2 && $c2 < 32) ## private [RFC1918]
124			\|\| ($c1 == 192 && (($c2 == 0 && $c3 == 2) ## "TEST-NET"
125			\|\| ($c2 == 88 && $c3 == 99) ## 6to4 anycast [RFC3068]
126			\|\| ($c2 == 168))) ## private [RFC1918]
127			\|\| ($c1 == 198 && ($c2 == 18 \|\| $c2 == 19)) ## benchmark [RFC2544]
128			\|\| ($c1 >= 224); ## class D,E [RFC3171]
129			}
130			$$o{fqdn} \|\|= '['.$$o{ip_address}.']';
131			}
132			if (!$$o{fqdn} && $$o{uucp}) {
133			$$o{uucp} .= '.uucp' if $self->{option}->{validate} && $$o{uucp} !~ /\.uucp/i;
134			$$o{fqdn} = $$o{uucp};
135			}
136			Carp::croak "Msg-ID generation: no FQDN"
137			if $self->{option}->{validate} && !$$o{fqdn};
138
139			$self->{id_right} = $$o{fqdn};
140
141			Carp::croak "Msg-ID generation: no 'login'"
142			if $self->{option}->{validate} && !$$o{login};
143			$$o{login} = $self->_hash ($$o{login}, $self->{option}->{hash_name});
144
145			my @s = ('0'..'9','a'..'z','-','=','_');
146	wakaba	1.5	my @t = ('0'..'9','a'..'z');
147			my $unique = $t[rand @t].$s[rand @s].$s[rand @s].$s[rand @s].'.';
148	wakaba	1.4	$unique .= join ('.', $self->_base39 (time), $self->_base39 ($$),
149			$self->_hash ($self->{option}->{software_name},
150			$self->{option}->{software_name_hash}));
151			$self->{id_left} = $unique
152			.'%'.($self->{option}->{hash_name} ne '%none'?
153			$self->_hash ($self->{option}->{hash_name}, '%none') .'%': '')
154			.$$o{login}
155			.($$o{subject_changed}? '-_-': '');
156
157			$self;
158	wakaba	1.2	}
159	wakaba	1.1
160	wakaba	1.4	sub _hash ($$;$$) {
161	wakaba	1.1	my $self = shift;
162	wakaba	1.4	my ($str, $hash_name, $add_unsafe) = (shift, lc shift, shift);
163			$add_unsafe \|\|= qr#[/.=\x09\x20]#;
164			undef $hash_name if $hash_name eq '%none';
165			if ($hash_name eq 'md5') {
166			eval {require Digest::MD5} or Carp::croak "Msg-ID generation: $@";
167			$str = Digest::MD5::md5_base64 ($str);
168			} elsif ($hash_name eq 'sha1') {
169			eval {require Digest::SHA1} or Carp::croak "Msg-ID generation: $@";
170			$str = Digest::SHA1::sha1_base64 ($str);
171			} elsif ($hash_name eq 'md2') {
172			eval {require Digest::MD2} or Carp::croak "Msg-ID generation: $@";
173			$str = Digest::MD2::md2_base64 ($str);
174			} elsif ($hash_name eq 'crypt') {
175			my @s = ('0'..'9','A'..'Z','a'..'z');
176			my $salt = crypt('foobar', '$1$ab$') eq '$1$ab$uAP8qWqcFs3q.Gfl5PkL2.'?
177			'$1$'.join('', map($s[rand @s], 1..8)).'$': $s[rand @s].$s[rand @s];
178			$str = crypt ($str, $salt);
179	wakaba	1.1	}
180	wakaba	1.4	$str =~ s#($add_unsafe)#sprintf('=%02X', ord($1))#ge;
181			$str =~ s/($REG{NON_atext_dot})/sprintf('=%02X', ord($1))/ge;
182			$str;
183	wakaba	1.1	}
184
185	wakaba	1.4	sub _base39 ($$) {
186	wakaba	1.1	my $self = shift;
187	wakaba	1.4	my $number = shift;
188			my @digit = ('0'..'9','a'..'z','-','=','_');
189			my $ret = '';
190
191			my ($rem);
192			while ($number > 0) {
193			$rem = $number % @digit;
194			$ret = $digit[ $rem ].$ret;
195			$number = ($number - $rem) / @digit;
196			}
197			$ret;
198	wakaba	1.1	}
199
200	wakaba	1.4	sub generate ($%) {
201	wakaba	1.1	my $self = shift;
202	wakaba	1.4	my %parameter = @_;
203			for (grep {/^-/} keys %parameter) {$parameter{substr ($_, 1)} = $parameter{$_}}
204			$self->_newid (\%parameter);
205	wakaba	1.1	}
206
207	wakaba	1.4	sub id_left ($) {
208	wakaba	1.1	my $self = shift;
209	wakaba	1.4	my %e = &{$self->{option}->{hook_encode_string}} ($self,
210			$self->{id_left}, type => 'local-part');
211			Message::Util::quote_unsafe_string ($e{value},
212			unsafe_regex => qr/$REG{NON_atext_dot}\|^\.\|\.$/);
213	wakaba	1.1	}
214	wakaba	1.4	sub id_right ($) {
215	wakaba	1.3	my $self = shift;
216	wakaba	1.4	#my %e = &{$self->{option}->{hook_encode_string}} ($self,
217			# $self->{id_right}, type => 'domain');
218			#Message::Util::quote_unsafe_domain ($e{value});
219			Message::Util::quote_unsafe_domain ($self->{id_right});
220	wakaba	1.3	}
221	wakaba	1.4	sub content ($) {
222	wakaba	1.1	my $self = shift;
223	wakaba	1.4	my ($l, $r) = ($self->id_left, $self->id_right);
224			sprintf '%s@%s', $l, $r if $l && $r;
225	wakaba	1.1	}
226
227	wakaba	1.4	sub stringify ($;%) {
228	wakaba	1.1	my $self = shift;
229	wakaba	1.4	my ($l, $r) = ($self->id_left, $self->id_right);
230			sprintf '<%s@%s>', $l, $r if $l && $r;
231	wakaba	1.1	}
232	wakaba	1.4	*as_string = \&stringify;
233	wakaba	1.1
234	wakaba	1.4	=head1 EXAMPLE
235	wakaba	1.1
236	wakaba	1.4	use Message::Field::MsgID;
237			my $from = 'foo@bar.example';
238			my $login = 'my-login-name';
239			my $domain = 'foo.bar.example';
240			my $ipv4 = '192.168.0.1';
241			my %mid;
242			$mid{no_crypt} = new Message::Field::MsgID
243			addr_spec => $from, -validate => 0;
244			$mid{md5} = new Message::Field::MsgID
245			login => $login, ip_address => $ipv4,
246			-hash_name => 'md5', -validate => 0;
247			$mid{sha1} = new Message::Field::MsgID
248			login => $login, fqdn => $domain, subject_changed => 1,
249			-hash_name => 'sha1', -validate => 0;
250			for (keys %mid) {
251			print $_, ":\t", $mid{$_}, "\n";
252			}
253			# sha1: <t-9.bbxkfu.xsem.MFMMpm%sha1%9pnH2R6iN8KSIMby+dPU0i3M8RU-_-@foo.bar.example>
254			# md5: <7fu.bbxkfu.xsem.MFMMpm%md5%eBpd+12mupwxZBc6kMWR9g@[192.168.0.1]>
255			# no_crypt: <3vy.bbxkfu.xsem.MFMMpm%foo@bar.example>
256
257			## IMPORTANT NOTE: This example uses -validate option with
258			## '0' (does not validate) value since it uses example (invalid)
259			## resource names, such as 'foo.bar.example'. Usually, this option
260			## shall not be used (and default value = '1' = does validate
261			## should be used).
262	wakaba	1.1
263	wakaba	1.4	=head1 SEE ALSO
264	wakaba	1.1
265	wakaba	1.4	RFC 822 E<lt>urn:ietf:rfc:822E<gt>, RFC 2822 E<lt>urn:ietf:rfc:2822E<gt>
266	wakaba	1.1
267	wakaba	1.4	RFC 850 E<lt>urn:ietf:rfc:850E<gt>, RFC 1036 E<lt>urn:ietf:rfc:1036E<gt>,
268			son-of-RFC1036, draft-ietf-usefor-article-06.txt
269			E<lt>urn:ietf:id:draft-ietf-usefor-article-06E<gt>
270	wakaba	1.1
271	wakaba	1.4	draft-ietf-usefor-message-id-01.txt
272			E<lt>urn:ietf:id:draft-ietf-usefor-message-id-01E<gt>
273	wakaba	1.1
274	wakaba	1.4	draft-ietf-usefor-msg-id-alt-00.txt
275			E<lt>urn:ietf:id:draft-ietf-usefor-msg-id-alt-00E<gt>
276	wakaba	1.1
277			=head1 LICENSE
278
279			Copyright 2002 wakaba E<lt>w@suika.fam.cxE<gt>.
280
281			This program is free software; you can redistribute it and/or modify
282			it under the terms of the GNU General Public License as published by
283			the Free Software Foundation; either version 2 of the License, or
284			(at your option) any later version.
285
286			This program is distributed in the hope that it will be useful,
287			but WITHOUT ANY WARRANTY; without even the implied warranty of
288			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
289			GNU General Public License for more details.
290
291			You should have received a copy of the GNU General Public License
292			along with this program; see the file COPYING. If not, write to
293			the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
294			Boston, MA 02111-1307, USA.
295
296			=head1 CHANGE
297
298			See F<ChangeLog>.
299	wakaba	1.6	$Date: 2002/05/14 13:42:40 $
300	wakaba	1.1
301			=cut
302
303			1;