1DateTime::Format::Mail(U3s)er Contributed Perl DocumentatDiaotneTime::Format::Mail(3)
2
3
4
6 DateTime::Format::Mail - Convert between DateTime and RFC2822/822
7 formats
8
10 use DateTime::Format::Mail;
11
12 # From RFC2822 via class method:
13
14 my $datetime = DateTime::Format::Mail->parse_datetime(
15 "Sat, 29 Mar 2003 22:11:18 -0800"
16 );
17 print $datetime->ymd('.'); # "2003.03.29"
18
19 # or via an object
20
21 my $pf = DateTime::Format::Mail->new();
22 print $pf->parse_datetime(
23 "Fri, 23 Nov 2001 21:57:24 -0600"
24 )->ymd; # "2001-11-23"
25
26 # Back to RFC2822 date
27
28 use DateTime;
29 my $dt = DateTime->new(
30 year => 1979, month => 7, day => 16,
31 hour => 16, minute => 45, second => 20,
32 time_zone => "Australia/Sydney"
33 );
34 my $str = DateTime::Format::Mail->format_datetime( $dt );
35 print $str; # "Mon, 16 Jul 1979 16:45:20 +1000"
36
37 # or via an object
38 $str = $pf->format_datetime( $dt );
39 print $str; # "Mon, 16 Jul 1979 16:45:20 +1000"
40
42 RFCs 2822 and 822 specify date formats to be used by email. This module
43 parses and emits such dates.
44
45 RFC2822 (April 2001) introduces a slightly different format of date
46 than that used by RFC822 (August 1982). The main correction is that the
47 preferred format is more limited, and thus easier to parse
48 programmatically.
49
50 Despite the ease of generating and parsing perfectly valid RFC822 and
51 RFC2822 people still get it wrong. So this module provides four things
52 for those handling mail dates:
53
54 1. A strict parser that will only accept RFC2822 dates, so you can see
55 where you're right.
56
57 2. A strict formatter, so you can generate the right stuff to begin
58 with.
59
60 3. A loose parser, so you can take the misbegotten output from other
61 programs and turn it into something useful. This includes various
62 minor errors as well as some somewhat more bizarre mistakes. The
63 file t/sample_dates in this module's distribution should give you
64 an idea of what's valid, while t/invalid.t should do the same for
65 what's not. Those regarded as invalid are just a bit too strange to
66 allow.
67
68 4. Interoperation with the rest of the DateTime suite. These are a
69 collection of modules to handle dates in a modern and accurate
70 fashion. In particular, they make it trivial to parse, manipulate
71 and then format dates. Shifting timezones is a doddle, and
72 converting between formats is a cinch.
73
74 As a future direction, I'm contemplating an even stricter parser that
75 will only accept dates with no obsolete elements.
76
78 new
79 Creates a new "DateTime::Format::Mail" instance. This is generally not
80 required for simple operations. If you wish to use a different parsing
81 style from the default, strict, parser then you'll need to create an
82 object.
83
84 my $parser = DateTime::Format::Mail->new()
85 my $copy = $parser->new();
86
87 If called on an existing object then it clones the object.
88
89 It has two optional named parameters.
90
91 • "loose" should be a true value if you want a loose parser, else
92 either don't specify it or give it a false value.
93
94 • "year_cutoff" should be an integer greater than or equal to zero
95 specifying the cutoff year. See "set_year_cutoff" for details.
96
97 my $loose = DateTime::Format::Mail->new( loose => 1 );
98
99 my $post_2049 = DateTime::Format::Mail->new(
100 year_cutoff => 60
101 );
102
103 clone
104 For those who prefer to explicitly clone via a method called "clone()".
105 If called as a class method it will die.
106
107 my $clone = $original->clone();
108
110 These methods work on either our objects or as class methods.
111
112 loose, strict
113 These methods set the parsing strictness.
114
115 my $parser = DateTime::Format::Mail->new;
116 $parser->loose;
117 $parser->strict; # (the default)
118
119 my $p = DateTime::Format::Mail->new->loose;
120
121 parse_datetime
122 Given an RFC2822 or 822 datetime string, return a "DateTime" object
123 representing that date and time. Unparseable strings will cause the
124 method to die.
125
126 See the synopsis for examples.
127
128 set_year_cutoff
129 Two digit years are treated as valid in the loose translation and are
130 translated up to a 19xx or 20xx figure. By default, following the
131 specification of RFC2822, if the year is greater than '49', it's
132 treated as being in the 20th century (19xx). If lower, or equal, then
133 the 21st (20xx). That is, 50 becomes 1950 while 49 is 2049.
134
135 "set_year_cutoff()" allows you to modify this behaviour by specifying a
136 different cutoff.
137
138 The return value is the object itself.
139
140 $parser->set_year_cutoff( 60 );
141
142 year_cutoff
143 Returns the current cutoff. Can be used as either a class or object
144 method.
145
146 my $cutoff = $parser->set_year_cutoff;
147
148 default_cutoff
149 Returns the default cutoff. A useful method to override for subclasses.
150
151 my $default = $parser->default_cutoff;
152
153 fix_year
154 Takes a year and returns it normalized.
155
156 my $fixed = $parser->fix_year( 3 );
157
159 format_datetime
160 Given a "DateTime" object, return it as an RFC2822 compliant string.
161
162 use DateTime;
163 use DateTime::Format::Mail;
164 my $dt = DateTime->new(
165 year => 1979, month => 7, day => 16, time_zone => 'UTC'
166 );
167 my $mail = DateTime::Format::Mail->format_datetime( $dt );
168 print $mail, "\n";
169
170 # or via an object
171 my $formatter = DateTime::Format::Mail->new();
172 my $rfcdate = $formatter->format_datetime( $dt );
173 print $rfcdate, "\n";
174
176 Dave Rolsky (DROLSKY) for kickstarting the DateTime project.
177
178 Roderick A. Anderson for noting where the documentation was incomplete
179 in places.
180
181 Joshua Hoblitt (JHOBLITT) for inspiring me to check what the standard
182 said about interpreting two digit years.
183
185 Support for this module is provided via the datetime@perl.org email
186 list. See <http://datetime.perl.org/mailing_list.html> for more
187 details.
188
189 Alternatively, log them via the CPAN RT system via the web or email:
190
191 http://rt.cpan.org/NoAuth/ReportBug.html?Queue=DateTime-Format-Mail
192 bug-datetime-format-mail@rt.cpan.org
193
194 This makes it much easier for me to track things and thus means your
195 problem is less likely to be neglected.
196
198 Copyright © Iain Truskett, 2003. All rights reserved.
199
200 This library is free software; you can redistribute it and/or modify it
201 under the same terms as Perl itself.
202
203 The full text of the licences can be found in the LICENSE file included
204 with this module, or in perlartistic and perlgpl in Perl 5.8.1 or
205 later.
206
208 Originally written by Iain Truskett <spoon@cpan.org>, who died on
209 December 29, 2003.
210
211 Maintained by Dave Rolsky <autarch@urth.org> from 2003 to 2013.
212
213 Maintained by Philippe Bruhat (BooK) <book@cpan.org> since 2014.
214
216 "datetime@perl.org" mailing list.
217
218 <http://datetime.perl.org/>
219
220 perl, DateTime
221
222 RFCs 2822 and 822.
223
224
225
226perl v5.34.0 2022-01-21 DateTime::Format::Mail(3)