WARNING: This code is in an evaluation phase until 1 August 1996. Depending on any comments/complaints received before this cutoff date, the interface may change in a non-backwards-compatible manner.
use MIME::Parser;
# Create a new parser object:
my $parser = new MIME::Parser;
# Optional: set up parameters that will affect how it extracts
# documents from the input stream:
$parser->output_dir("$ENV{HOME}/mimemail");
# Parse an input stream:
$entity = $parser->read(\*STDIN) or die "couldn't parse MIME stream";
# Congratulations: you now have a (possibly multipart) MIME entity!
$entity->dump_skeleton; # for debugging
my $parser = new MIME::Parser;
$parser->output_dir("/tmp");
$parser->output_prefix("msg1");
my $entity = $parser->read(\*STDIN);
".".
If OPTVALUE is not
given, the current output directory is returned. If OPTVALUE is
given, the output directory is set to the new value, and the previous value
is returned.
Normally, the ``directory'' portion will be the output_dir(), and the ``filename'' portion will be the recommended filename extracted
from the MIME header (or some simple temporary file name, starting with the
output_prefix(), if the header does not specify a filename).
If there is a recommended filename, but it is judged to be evil (if it is empty, or if it contains ``/''s or ``..''s or non-ASCII characters), then a warning is issued and the temporary file name is used in its place. This may be overly restrictive, so...
NOTE:
If you don't like the behavior of this function, you can change it by
installing your own routine. See output_path_hook()
for details.
Thanks to Laurent Amon for pointing out problems with the original implementation, and for making some good suggestions.
sub my_output_path_hook {
my $parser = shift; # this MIME::Parser
my $head = shift; # the MIME::Head for the current message
# Your code here: it must return a path that can be
# open()ed for writing. Remember that you can ask the
# $parser about the output_dir, and you can ask the
# $head about the recommended_filename!
}
And install it immediately before parsing the input stream, like this:
# Create a new parser object, and install my own output_path hook:
my $parser = new MIME::Parser;
$parser->output_path_hook(\&my_output_path_hook);
# NOW we can parse an input stream:
$entity = $parser->read(\*STDIN);
Get/set the output directory for the parsing operation. This is a short string that all filenames for extracted and decoded body parts will begin with. The default is "msg" .
If OPTVALUE is not
given, the current output prefix is returned. If OPTVALUE is
given, the output directory is set to the new value, and the previous value
is returned.
read(), intended for programs running under mail-handlers like deliver
, which splits the incoming mail message into a header file and a body
file.
Simply give this method the paths to the respective files. These must be pathnames: Perl ``open-able'' expressions won't work, since the pathnames are shell-quoted for safety.
WARNING: it is assumed that, once the files are cat'ed together, there will be a blank line separating the head part and the body part.
output_dir().
The stream should be given as a glob ref to a readable FILEHANDLE; e.g., \*STDIN.
Returns a MIME::Entity, which may be a single entity, or an arbitrarily-nested multipart entity. Returns undef on failure.
multipart-body := preamble 1*encapsulation close-delimiter epilogue
encapsulation := delimiter body-part CRLF
delimiter := "--" boundary CRLF
; taken from Content-Type field.
; There must be no space between "--"
; and boundary.
close-delimiter := "--" boundary "--" CRLF
; Again, no space by "--"
preamble := discard-text
; to be ignored upon receipt.
epilogue := discard-text
; to be ignored upon receipt.
discard-text := *(*text CRLF)
body-part := <"message" as defined in RFC 822, with all
header fields optional, and with the specified
delimiter not occurring anywhere in the message
body, either on a line by itself or as a substring
anywhere. Note that the semantics of a part
differ from the semantics of a message, as
described in the text.>
From this we glean the following algorithm for parsing a MIME stream:
PROCEDURE parse
INPUT
A FILEHANDLE for the stream.
An optional end-of-stream OUTER_BOUND (for a nested multipart message).
RETURNS
The (possibly-multipart) ENTITY that was parsed.
A STATE indicating how we left things: "END" or "ERROR".
BEGIN
LET OUTER_DELIM = "--OUTER_BOUND".
LET OUTER_CLOSE = "--OUTER_BOUND--".
LET ENTITY = a new MIME entity object.
LET STATE = "OK".
Parse the (possibly empty) header, up to and including the
blank line that terminates it. Store it in the ENTITY.
IF the MIME type is "multipart":
LET INNER_BOUND = get multipart "boundary" from header.
LET INNER_DELIM = "--INNER_BOUND".
LET INNER_CLOSE = "--INNER_BOUND--".
Parse preamble:
REPEAT:
Read (and discard) next line
UNTIL (line is INNER_DELIM) OR we hit EOF (error).
Parse parts:
REPEAT:
LET (PART, STATE) = parse(FILEHANDLE, INNER_BOUND).
Add PART to ENTITY.
UNTIL (STATE != "DELIM").
Parse epilogue:
REPEAT (to parse epilogue):
Read (and discard) next line
UNTIL (line is OUTER_DELIM or OUTER_CLOSE) OR we hit EOF
LET STATE = "EOF", "DELIM", or "CLOSE" accordingly.
ELSE (if the MIME type is not "multipart"):
Open output destination (e.g., a file)
DO:
Read, decode, and output data from FILEHANDLE
UNTIL (line is OUTER_DELIM or OUTER_CLOSE) OR we hit EOF.
LET STATE = "EOF", "DELIM", or "CLOSE" accordingly.
ENDIF
RETURN (ENTITY, STATE).
END
For reasons discussed in MIME::Entity, we can't just discard the ``discard text'': some mailers actually put data in the preamble.
A better solution for this case would be to set up some form of state machine for input processing. This will be left for future versions.
The revised implementation uses temporary files (a la tmpfile()) to hold the encoded portions of MIME documents. Such files are deleted
automatically after decoding is done, and no more than one such file is
opened at a time, so you should never need to worry about them.
"\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.
"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
.
All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.