MIME-tools - modules for parsing (and creating!) MIME entities
MIME-tools is a collection of Perl5 MIME:: modules for parsing and decoding single- or multipart (even nested multipart) MIME messages.
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...
A MIME::Head (a subclass of Mail::Header) which holds the MIME header data.
A MIME::Body, which is a object that knows where the body data is. You ask this object to "open" itself for reading, and it will hand you back an "I/O handle" for reading the data: this is a FileHandle-like object, and could be of any class, so long as it conforms to a subset of the IO::Handle interface. Most of the MIME:: modules will automatically wrap raw (unblessed) filehandles inside MIME::IO objects, so that they conform to this interface.
Here's a simple example, which reads a MIME stream from STDIN and outputs all extracted parts to files in the given directory (and yes, you no longer have to output to files!):
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;
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.
If you want to tweak the way this toolkit works (for example, to turn on debugging), use the routines in the MIME::ToolUtils module.
On a small scale, the MIME::Decoder can be used to encode as well. When encoding an 8-bit document as a 7-bit mail message (a no-no, but allowed), the 8-bit characters are escaped for you into reasonable ASCII sequences, by the MIME::Latin1 module.
Here's an example, which composes and sends a MIME message containing two parts: a text file, and an attached GIF:
use MIME::Entity; # Create the top-level, and set up the mail headers: $top = build MIME::Entity Type=>"multipart/mixed"; $top->head->add('from', "me\@myhost.com"); $top->head->add('to', "you\@yourhost.com"); $top->head->add('subject', "Hello, nurse!"); # Attachment #1: a simple text document: attach $top Path=>"./testin/short.txt"; # Attachment #2: a GIF file: attach $top Path => "./docs/mime-sm.gif", Type => "image/gif", Encoding => "base64"; # Send it: open MAIL, "| /usr/lib/sendmail -t -i" or die "open: $!"; $top->print(\*MAIL); close MAIL;
I'm working on making this even easier (in particular, to make it easier for you to set up the data for each attachment, and to test the interface with Mail::Send). I'd also like to make it so that the content-type and encoding can be automatically inferred from the file's path.
Module DSLI Description Info ---------- ---- ---------------------------------------- ---- MIME:: ::Decoder adpO OO interface for decoding MIME messages ERYQ ::Entity adpO An extracted and decoded MIME entity ERYQ ::Head adpO A parsed MIME header ERYQ ::IO adpO Simple I/O handles for filehandles/scalars ERYQ ::Latin1 adpO Encoding 8-bit Latin-1 as 7-bit ASCII ERYQ ::Parser adpO Parses streams to create MIME entities ERYQ ::ParserBase adpO For building your own MIME parser ERYQ
./MIME/*.pm the MIME-tools classes ./Makefile.PL the input to MakeMaker ./COPYING terms and conditions for copying/using the software ./README this file ./docs/ HTMLized documentation ./etc/ convenient copies of other modules you may need ./testin/ files you can use for testing (as in "make test") ./testout/ the output of "make test"
You'll need Perl5.002 or better.
It might work with 5.001m+, but you'll need to get ahold of the "vars" module. For this reason, I don't yet "require 5.002" in my modules.
Obtain and install the following kits from the CPAN:
MIME::QuotedPrint MIME::Base64 MailTools: (1.06 or higher) Mail::Header Mail::Internet etc...
For your convenience, possibly-old copies are provided in the ./etc directory, of the distribution, but they are NOT installed for you during the installation procedure.
Pretty simple:
1. Gunzip and de-tar the distribution, and cd to the top level. 2. Type: perl Makefile.PL 3. Type: make # this step is optional 4. Type: make test # this step is optional 5. Type: make install
Other interesting targets in the Makefile are:
make config # to check if the Makefile is up-to-date make clean # delete local temp files (Makefile gets renamed) make realclean # delete derived files (including ./blib)
If you're installing this as a replacement for the MIME-parser 1.x release, and you really don't want to break existing code, you should do this at any point before the code is invoked:
use MIME::ToolUtils; MIME::ToolUtils->emulate_version(1.0);
Try not to get too attached to this, though. Instead, plan on upgrading your code ASAP to the 2.0 style.
I quote from Achim Bohnet, who gave feedback on v.1.9 (I think he's using the word header where I would use field; e.g., to refer to "Subject:", "Content-type:", etc.):
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.
However, in my mind's eye, I see an abstract class, call it MIME::Attrs, 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 of MIME::Head: that way, MIME::Head would have to implement its interface, and allow itself to be initiallized from a MIME::Attrs object.
When I originally wrote this module for the CPAN, I agonized for a long time about whether or not it really should just be a subclass of Mail::Internet (then at version 1.17). There were plusses:
Software reuse.
Inheritance of the mail-sending utilities.
And, unfortunately, minuses:
The Mail::Internet 1.17 model of messages as being short enough to fit into in-core arrays is excellent for most email applications; however, it seemed ill-suited for generic MIME applications, where MIME streams could be megabytes long.
The implementation of Mail::Internet 1.17 was excellent for certain kinds of header manipulation, but the implementation of get() was less-efficient than I would have liked for MIME applications.
get()
In my heart of hearts, I honestly felt that the head should be encapsulated as a first-class object, and in Mail::Internet 1.17 it was not.
So I chose to make MIME::Head and MIME::Entity their own standalone modules.
Since that time, I worked with Graham Barr (author of most of the MailTools package, and a darn nice guy to "work" with over email), and he has graciously evolved the MailTools modules into a direction that addressed a lot of these issues.
With MailTools now its 1.06 release, it was finally time to finish what I started, and release MIME-tools 2.0.
RFC-1521 dictates that MIME streams have lines terminated by CRLF ("\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.
"\r\n"
"\n"
An attempt has been made to allow the parser to handle both CRLF and newline-terminated input.
The "7bit" and "8bit" decoders will decode both a "\n" and a "\r\n" end-of-line sequence into a "\n".
"7bit"
"8bit"
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.
"binary"
All encoders currently output the end-of-line sequence as a "\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.
A bug in MIME::Entity's output method was corrected. MIME::Entity::print now outputs everything to the desired filehandle explicitly. Thanks to Jake Morrison for pointing out the incompatibility with Mail::Header.
Fixed transposed "if" statement, removing spurious printing of header from MIME::Parser, and fixing bug in autogenerated filenames. (Annoyingly, this bug is invisible if debugging is turned on!) Thanks to Andreas Koenig for bringing this to my attention.
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.
Stupid, stupid bugs in both BASE64 encoding and decoding. Thanks to Phil Abercrombie for locating them.
Modules now inherit from the new Mail:: modules! This means big changes in behavior.
Added option to parse "message/rfc822" as a pseduo-multipart document. Thanks to Andreas Koenig for suggesting this.
"message/rfc822"
MIME::Parser can now store message data in-core. There were a lot of requestes for this feature.
MIME::Entity can now compose messages. There were a lot of requestes for this feature.
MIME::Head now no longer requires space after ":", although either a space or a tab after the ":" will be swallowed if there. Thanks to Igor Starovoitov for pointing out this shortcoming.
Fixed bugs in parser where CRLF-terminated lines were blowing out the handling of preambles/epilogues. Thanks to Russell Sutherland for reporting this bug.
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.
Converted over to using Makefile.PL. Thanks to Andreas Koenig for the much-needed kick in the pants...
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 typo was causing the epilogue of an inner multipart message to be swallowed to the end of the OUTER multipart message; this has now been fixed. Thanks to Igor Starovoitov for reporting this bug.
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!
No changes: 1.8 failed CPAN registration
Fixed incompatibility with 5.001 and FileHandle::new_tmpfile Added COPYING file, and improved README.
Dress up mimedump and mimeexplode utilities to take cmd line options for directory, environment vars (MIMEDUMP_OUTPUT, etc.).
Make it even easier to compose and send MIME messages.
Make VERSION a bit more sensible (2.8, 2.9, 2.10 effective goes backwards...).
Copyright (c) 1996 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.
The MIME format is documented in RFC 1521.
The MIME header format is documented in RFC 822.
MIME-tools was created by:
Eryq, eryq@rhine.gsfc.nasa.gov
Initial release (1.0): 28 April 1996. Re-release (2.0): Halloween 1996.
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 Andreas Koenig Numerous good ideas, tons of beta testing, and help with CPAN-friendly packaging Igor Starovoitov Bug reports and suggestions
Not to mention the Accidental Beta Test Team, whose bug reports have been invaluable in improving the whole:
Phil Abercrombie Jake Morrison Joel Noble Andrew Pimlott Russell Sutherland Larry Virden
Please forgive me if I've left you out. Or email me.
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cpanm
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