I’ve recently been seeing and increase in spam emails for my fourthwoods.com accounts. I started playing with a perl script to process the spam messages to feed to SpamAssassin. When I finish it I’ll post an article on here describing what I did and why. Hopefully it will be helpful to somebody.
Anyway, this was the first I used the
MIME::Parser and related perl classes so I muddled my way through following some examples and reading the perl documentation. I did run across an error that wasn’t immediately obvious what was causing it. According to the examples, I was doing everything correctly. However, I ran into the following:
Can't call method "bodyhandle" on an undefined value at foo.pl line XX.
Ok, so I’m parsing a multipart message following along with this example and every time I try to access the
bodyhandle I get the error. WTF?? My code isn’t that much different from the example. If I iterate through all the
parts the data is there, so why no
Digging through the documentation for
bodyhandle “An entity will have either a body or parts: not both.” Aha! Ok, so when will there be
parts and when will there be a
bodyhandle? Well, it depends on the mime-type and whether or not the parser is set up to extract nested messages. In my case I’m concerned with mime-type “message/rfc822” which according to the table, if the parser is configured to extract nested messages the nested messages are parsed and put into an array of
MIME::Entity objects returned by the
parts method. If the parser is not to extract nested messages, they are placed into a
MIME::Body object returned by
MIME::Parser, according to the documentation for the
extract_nested_messages option it defaults to
true which causes my issue. To prevent extraction of nested messages and instead get a valid
extract_nested_messages must be set to
false or 0.
In the example that I was following they do not ever set this option to
false however, they also do not seem to be particularly interested in my specific case. I did see that sal-wrapper.pl does in fact set this option so I know I’m not nuts!