MIME::Tools | MIME::Body | MIME::Decoder | MIME::Entity |
MIME::Head | MIME::IO | MIME::Latin1 | MIME::Parser |
MIME::ParserBase | MIME::ToolUtils | MIME::Tools | MIME::Words |
MIME:: |
MIME-tools - modules for parsing (and creating!) MIME entities
Here's some pretty basic code for parsing a MIME message, and outputting its decoded components to a given directory:
use MIME::Parser;
# Create parser, and set the output directory: my $parser = new MIME::Parser; $parser->output_dir("$ENV{HOME}/mimemail");
# Parse input: $entity = $parser->read(\*STDIN) or die "couldn't parse MIME stream";
# Take a look at the top-level entity (and any parts it has): $entity->dump_skeleton;
Here's some code which composes and sends a MIME message containing three parts: a text file, an attached GIF, and some more text:
use MIME::Entity;
# Create the top-level, and set up the mail headers: $top = build MIME::Entity Type =>"multipart/mixed", From => "me\@myhost.com", To => "you\@yourhost.com", Subject => "Hello, nurse!";
# Part #1: a simple text document: attach $top Path=>"./testin/short.txt";
# Part #2: a GIF file: attach $top Path => "./docs/mime-sm.gif", Type => "image/gif", Encoding => "base64";
# Part #3: some literal text: attach $top Data=>$message;
# Send it: open MAIL, "| /usr/lib/sendmail -t -i" or die "open: $!"; $top->print(\*MAIL); close MAIL;
MIME-tools is a collection of Perl5 MIME:: modules for parsing, decoding, and generating single- or multipart (even nested multipart) MIME messages. (Yes, kids, that means you can send messages with attached GIF files).
Here are the classes you'll generally be dealing with directly:
.------------. .------------. | MIME:: |------>| MIME:: | | Parser | isa | ParserBase | `------------' `------------' | parse() | returns a... | | | | head() .--------. | returns... | MIME:: | get() V .-------->| Head | etc... .--------./ `--------' .---> | MIME:: | `-----| Entity | .--------. parts() `--------'\ | MIME:: | returns `-------->| Body | sub-entities bodyhandle() `--------' (if any) returns... | open() | returns... | V .--------. read() | IO:: | getline() | Handle | print() `--------' etc...
To illustrate, parsing works this way:
A typical multipart message containing two parts -- a textual greeting and an "attached" GIF file -- would be a tree of MIME::Entity objects, each of which would have its own MIME::Head. Like this:
.--------. | MIME:: | Content-type: multipart/mixed | Entity | Subject: Happy Samhaine! `--------' | `----. parts | | .--------. |---| MIME:: | Content-type: text/plain; charset=us-ascii | | Entity | Content-transfer-encoding: 7bit | `--------' | .--------. |---| MIME:: | Content-type: image/gif | Entity | Content-transfer-encoding: base64 `--------' Content-disposition: inline; filename="hs.gif"
You usually start by creating an instance of MIME::Parser (a subclass of the abstract MIME::ParserBase), and setting up certain parsing parameters: what directory to save extracted files to, how to name the files, etc.
You then give that instance a readable filehandle on which waits a MIME message. If all goes well, you will get back a MIME::Entity object (a subclass of Mail::Internet), which consists of...
If the original message was a multipart document, the MIME::Entity object will have a non-empty list of "parts", each of which is in turn a MIME::Entity (which might also be a multipart entity, etc, etc...).
Internally, the parser (in MIME::ParserBase) asks for instances of MIME::Decoder whenever it needs to decode an encoded file. MIME::Decoder has a mapping from supported encodings (e.g., 'base64') to classes whose instances can decode them. You can add to this mapping to try out new/experiment encodings. You can also use MIME::Decoder by itself.
All message composition is done via the MIME::Entity class. For single-part messages, you can use the MIME::Entity/build constructor to create MIME entities very easily.
For multipart messages, you can start by creating a top-level
multipart
entity with MIME::Entity/build, and then use
the similar MIME::Entity/attach method to attach parts to
that message. Please note: what most people think of as
"a text message with an attached GIF file" is really a multipart
message with 2 parts: the first being the text message, and the
second being the GIF file.
When building MIME a entity, you'll have to provide two very important
pieces of information: the content type and the
content transfer encoding. The type is usually easy, as it is directly
determined by the file format; e.g., an HTML file is text/html
.
The encoding, however, is trickier... for example, some HTML files are
7bit
-compliant, but others might have very long lines and would need to be
sent quoted-printable
for reliability.
See the section on encoding/decoding for more details, as well as "A MIME PRIMER".
The MIME::Decoder class can be used to encode as well; this is done when printing MIME entities. All the standard encodings are supported (see "A MIME PRIMER" for details):
Encoding... Normally used when message contents are... ------------------------------------------------------------------- 7bit 7-bit data with under 1000 chars/line, or multipart. 8bit 8-bit data with under 1000 chars/line. binary 8-bit data with possibly long lines (or no line breaks). quoted-printable Text files with some 8-bit chars (e.g., Latin-1 text). base64 Binary files.
Which encoding you choose for a given document depends largely on (1) what you know about the document's contents (text vs binary), and (2) whether you need the resulting message to have a reliable encoding for 7-bit Internet email transport.
In general, only quoted-printable
and base64
guarantee reliable
transport of all data; the other three "no-encoding" encodings simply
pass the data through, and are only reliable if that data is 7bit ASCII
with under 1000 characters per line, and has no conflicts with the
multipart boundaries.
I've considered making it so that the content-type and encoding can be automatically inferred from the file's path, but that seems to be asking for trouble... or at least, for Mail::Cap...
If you want to tweak the way this toolkit works (for example, to turn on debugging), use the routines in the MIME::ToolUtils module.
$entity = eval { $parser->parse(\*INPUT) };
Parsing is a complex process, and some components may throw exceptions
if seriously-bad things happen. Since "seriously-bad" is in the
eye of the beholder, you're better off catching possible exceptions
instead of asking me to propagate undef
up the stack. Use of exceptions in
reusable modules is one of those religious issues we're never all
going to agree upon; thankfully, that's what eval{}
is good for.
Here are some excerpts from RFC-1521 explaining the terminology we use; each is accompanied by the equivalent in MIME:: module terms...
The term "message", when not further qualified, means either the (complete or "top-level") message being transferred on a network, or a message encapsulated in a body of type "message".
There currently is no explicit package for messages; under MIME::, messages are streams of data which may be read in from files or filehandles.
The term "body part", in this document, means one of the parts of the body of a multipart entity. A body part has a header and a body, so it makes sense to speak about the body of a body part.
Since a body part is just a kind of entity (see below), a body part is represented by an instance of MIME::Entity.
The term "entity", in this document, means either a message or a body part. All kinds of entities share the property that they have a header and a body.
An entity is represented by an instance of MIME::Entity. There are instance methods for recovering the header (a MIME::Head) and the body (a MIME::Body).
The term "body", when not further qualified, means the body of an entity, that is the body of either a message or of a body part.
A body is represented by an instance of MIME::Body. You get the body of an entity by sending it a bodyhandle() message.
As of 4.x, MIME-tools can no longer emulate the old MIME-parser distribution. If you're installing this as a replacement for the MIME-parser 1.x release, you'll have to do a little tinkering with your code.
There is also IMHO no requirement [for] MIME::Heads to look like [email] headers; so to speak, the MIME::Head [simply stores] the attributes of a complex object, e.g.:
new MIME::Head type => "text/plain", charset => ..., disposition => ..., ... ;
I agree in principle, but (alas and dammit) RFC-1521 says otherwise. RFC-1521 [MIME] headers are a syntactic subset of RFC-822 [email] headers. Perhaps a better name for these modules would be RFC1521:: instead of MIME::, but we're a little beyond that stage now. (Note: RFC-1521 has recently been obsoleted by RFCs 2045-2049, so it's just as well we didn't go that route...)
However, in my mind's eye, I see a mythical abstract class which does what Achim suggests... so you could say:
my $attrs = new MIME::Attrs type => "text/plain", charset => ..., disposition => ..., ... ;
We could even make it a superclass or companion class of MIME::Head, such that MIME::Head would allow itself to be initiallized from a MIME::Attrs object.
In the meanwhile, look at the build() and attach() methods of MIME::Entity: they follow the spirit of this mythical class.
"\r\n"
). However, it is extremely likely that folks will want to
parse MIME streams where each line ends in the local newline
character "\n"
instead.
An attempt has been made to allow the parser to handle both CRLF and newline-terminated input.
See MIME::ParserBase for further details.
"7bit"
and "8bit"
decoders will decode both
a "\n"
and a "\r\n"
end-of-line sequence into a "\n"
.
The "binary"
decoder (default if no encoding specified)
still outputs stuff verbatim... so a MIME message with CRLFs
and no explicit encoding will be output as a text file
that, on many systems, will have an annoying ^M at the end of
each line... but this is as it should be.
See MIME::ParserBase for further details.
"\n"
,
with the assumption that the local mail agent will perform
the conversion from newline to CRLF when sending the mail.
However, there probably should be an option to output CRLF as per RFC-1521. I'm currently working on a good mechanism for this.
See MIME::ParserBase for further details.
See MIME::ParserBase for further details.
So you need to parse (or create) MIME, but you're not quite up on the specifics? No problem...
This indicates what kind of data is in the MIME message, usually as majortype/minortype. The standard major types are shown below. A more-comprehensive listing may be found in RFC-2046.
application/octet-stream
, application/gzip
, application/postscript
...
audio/basic
...
image/gif
, image/jpeg
...
message/rfc822
...
multipart/mixed
, multipart/alternative
...
text/plain
, text/html
...
video/mpeg
...
This is how the message body is packaged up for safe transit. There are the 5 major MIME encodings. A more-comprehensive listing may be found in RFC-2045.
Copyright (c) 1996, 1997 by Eryq. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See the COPYING file in the distribution for details.
Please email me directly with questions/problems (see AUTHOR below).
If you want to be placed on an email distribution list (not a mailing list!) for MIME-tools, and receive bug reports, patches, and updates as to when new MIME-tools releases are planned, just email me and say so. If your project is using MIME-tools, it might not be a bad idea to find out about those bugs before they become problems...
Improved handling/saving of preamble/epilogue.
MIME::IO deprecated. You'll see IO::Scalar, IO::ScalarArray, and IO::Wrap to make this toolkit work.
MIME::Entity deep code. You can now deep-copy MIME entities (except for on-disk data files).
7bit and 8bit "encoders" no longer encode. As per RFC-2045, these just do a pass-through of the data, but they'll warn you if you send bad data through.
MIME::Entity suggests encoding. Now you can ask MIME::Entity's build() method to "suggest" a legal encoding based on the body and the content-type. No more guesswork! See the "mimesend" example.
New module structure for MIME::Decoder classes. It should be easier for you to see what's happening.
New MIME decoders!
Support added for decoding x-uuencode
, and for
decoding/encoding x-gzip64
. You'll need "gzip" to make
the latter work.
Quoted-printable back on track... and then some. The 'quoted-printable' decoder now uses the newest MIME::QuotedPrint, and amends its output with guideline #8 from RFC2049 (From/.). Thanks to Denis N. Antonioli for suggesting this.
The "multipart/digest" semantics are now preserved. Parts of digest messages have their mime_type() defaulted to "message/rfc822" instead of "text/plain", as per the RFC. Thanks to Carsten Heyl for suggesting this.
You can prevent recommended filenames from being output. This possible security hole has been plugged; when building MIME entities, you can specify a body path but suppress the filename in the header. Thanks to Jason L. Tibbitts for suggesting this.
MIME::Head::add() now no longer downcases its argument. Thanks to Brandon Browning & Jason L. Tibbitts for finding this bug.
MIME::ParserBase no longer defaults to RFC-1522-decoding headers. The documentation correctly stated that the default setting was to not RFC-1522-decode the headers. The code, on the other hand, was init'ing this parser option in the "on" position. This has been fixed.
MIME::ParserBase::parse_nested_messages reexamined. If you use this feature, please re-read the documentation. It explains a little more precisely what the ramifications are.
MIME::Entity tries harder to ensure MIME compliance. It is now a fatal error to use certain bad combinations of content type and encoding when "building", or to attempt to "attach" to anything that is not a multipart document. My apologies if this inconveniences anyone, but it was just too darn easy before for folks to create bad MIME, and gosh darn it, good libraries should at least try to protect you from mistakes.
The "make" now halts if you don't have the right stuff, provided your MakeMaker supports PREREQ_PM. See the "REQUIREMENTS" section for what you need to install this package. I still provide old courtesy copies of the MIME:: decoding modules. Thanks to Hugo van der Sanden for suggesting this.
The "make test" is far less chatty.
Okay, okay, STDERR is evil. Now a "make test"
will just give you
the important stuff: do a "make test TEST_VERBOSE=1"
if you want
the gory details (advisable if sending me a bug report).
Thanks to Andreas Koenig for suggesting this.
You can now parse a MIME message from a scalar, an array-of-scalars, or any MIME::IO-compliant object (including IO:: objects.) Take a look at parse_data() in MIME::ParserBase. The parser code has been modified to support the MIME::IO interface. Thanks to fellow Chicagoan Tim Pierce (and countless others) for asking.
More sensible toolkit configuration. A new config() method in MIME::ToolUtils makes a lot of toolkit-wide configuration cleaner. Your old calls will still work, but with deprecation warnings.
You can now sign messages just like in Mail::Internet. See MIME::Entity for the interface.
You can now remove signatures from messages just like in Mail::Internet. See MIME::Entity for the interface.
You can now compute/strip content lengths and other non-standard MIME fields. See sync_headers() in MIME::Entity. Thanks to Tim Pierce for bringing the basic problem to my attention.
Many warnings are now silent unless $^W is true.
That means unless you run your Perl with -w, you won't see deprecation
warnings, non-fatal-error messages, etc. But of course you run with
-w, so this doesn't affect you. :-)
Completed the 7-bit encodings in MIME::Latin1. We hadn't had complete coverage in the conversion from 8- to 7-bit; now we do. Thanks to Rolf Nelson for bringing this to my attention.
Fixed broken parse_two() in MIME::ParserBase. BTW, if your code worked with the "broken" code, it should still work. Thanks again to Tim Pierce for bringing this to my attention.
decode()
method in MIME::Head... just tell your parser
object that you want to decode_headers()
.
Thanks to Kent Boortz for providing the idea, and the baseline
RFC-1522-decoding code!
Building MIME messages is even easier.
Now, when you use MIME::Entity's build()
or attach()
,
you can also supply individual
mail headers to set (e.g., -Subject
, -From
, -To
).
Added Disposition
to MIME::Entity's build()
method.
Thanks to Kurt Freytag for suggesting this feature.
An X-Mailer
header is now output
by default in all MIME-Entity-prepared messages,
so any bad MIME we generate can be traced back to this toolkit.
Added purge()
method to MIME::Entity for deleteing leftover files.
Thanks to Jason L. Tibbitts III for suggesting this feature.
Added seek()
and tell()
methods to built-in MIME::IO classes.
Only guaranteed to work when reading!
Thanks to Jason L. Tibbitts III for suggesting this feature.
When parsing a multipart message with apparently no boundaries, the error message you get has been improved. Thanks to Andreas Koenig for suggesting this.
MIME::Entity's build()
method now warns you if you give it an illegal
boundary string, and substitutes one of its own.
MIME::Entity's build()
method now generates safer, fully-RFC-1521-compliant
boundary strings.
Bug in MIME::Decoder's install()
method was fixed.
Thanks to Rolf Nelson and Nickolay Saukh for finding this.
Changed FileHandle::new_tmpfile to FileHandle->new_tmpfile, so some Perl installations will be happier. Thanks to Larry W. Virden for finding this bug.
Gave =over
an arg of 4 in all PODs.
Thanks to Larry W. Virden for pointing out the problems of bare =over's
Fixed bug in MIME::Entity::body() where it was using the bodyhandle completely incorrectly. Thanks to Joel Noble for bringing this to my attention.
Fixed MIME::Head::VERSION so CPAN:: is happier. Thanks to Larry Virden for bringing this to my attention.
Fixed undefined-variable warnings when dumping skeleton (happened when there was no Subject: line) Thanks to Joel Noble for bringing this to my attention.
MIME::Parser can now store message data in-core. There were a lot of requests for this feature.
MIME::Entity can now compose messages. There were a lot of requests for this feature.
Added option to parse "message/rfc822"
as a pseduo-multipart document.
Thanks to Andreas Koenig for suggesting this.
Fixed idiotic is_multipart() bug. Thanks to Andreas Koenig for noticing it.
Added untested binmode() calls to parser for DOS, etc. systems. No idea if this will work...
Reorganized the output_path() methods to allow easy use of inheritance, as per Achim Bohnet's suggestion.
Changed MIME::Head to report mime_type more accurately.
POSIX module no longer loaded by Parser if perl >= 5.002. Hey, 5.001'ers: let me know if this breaks stuff, okay?
Added unsupported ./examples directory.
Added t/*.t files for testing. Eeeeeeeeeeeh...it's a start.
Fixed bug in default parsing routine for generating output paths; it was warning about evil filenames if there simply were no recommended filenames. D'oh!
Fixed redefined parts() method in Entity.
Fixed bugs in Head where field name wasn't being case folded.
A bad regexp for parameter names was causing some parameters to be parsed incorrectly; this has also been fixed. Thanks again to Igor Starovoitov for reporting this bug.
It is now possible to get full control of the filenaming algorithm before output files are generated, and the default algorithm is safer. Thanks to Laurent Amon for pointing out the problems, and suggesting some solutions.
Fixed illegal "simple" multipart test file. D'OH!
MIME-tools was created by:
___ _ _ _ _ ___ _ / _ \| '_| | | |/ _ ' / Eryq (President, Zero G Inc.) | __/| | | |_| | |_| | http://www.zeegee.com/ \___||_| \__, |\__, |__ eryq@zeegee.com |___/ |___/
Release as MIME-parser (1.0): 28 April 1996. Release as MIME-tools (2.0): Halloween 1996. Release of 4.0: Christmas 1997.
$Revision: 4.116 $
This kit would not have been possible but for the direct contributions of the following:
Gisle Aas The MIME encoding/decoding modules. Laurent Amon Bug reports and suggestions. Graham Barr The new MailTools. Achim Bohnet Numerous good suggestions, including the I/O model. Kent Boortz Initial code for RFC-1522-decoding of MIME headers. Andreas Koenig Numerous good ideas, tons of beta testing, and help with CPAN-friendly packaging. Igor Starovoitov Bug reports and suggestions. Jason L Tibbitts III Bug reports, suggestions, patches.
Not to mention the Accidental Beta Test Team, whose bug reports (and comments) have been invaluable in improving the whole:
Phil Abercrombie Brandon Browning Kurt Freytag Steve Kilbane Jake Morrison Rolf Nelson Joel Noble Michael W. Normandin Tim Pierce Andrew Pimlott Dragomir R. Radev Nickolay Saukh Russell Sutherland Larry Virden Zyx
Please forgive me if I've accidentally left you out. Better yet, email me, and I'll put you in.
Users of this toolkit may wish to read the documentation of Mail::Header and Mail::Internet.
The MIME format is documented in RFCs 1521-1522, and more recently in RFCs 2045-2049.
The MIME header format is an outgrowth of the mail header format documented in RFC 822.