[Pan-users] Re: 'hundreds' of strange extracted file when downloadingmultipart messages

[Duncan]

Travis <address@hidden> posted
address@hidden, excerpted below, on  Thu, 24
Apr 2008 06:57:44 -0700:

> ----- Original Message -----

>> I run pan version 0.132.
>>
>> When I download a multipart message from news.usenetserver.com I get a
>> lot of files with names like :
>>
>> M8WPj.14920$HY2.13951-epkf52SaZeZP2roSf1MJ43itZ/
>> address@hidden
>>
>> I got other extension too (so not only with usenetserver.com.msg).

> You have Pan set to save "text" as well as the attachments.

Travis is correct, depending on where you are looking, but here's a 
somewhat more detailed explanation.

Pan saves messages using the (sanitized to filesystem safe) Message-ID, 
which according to the RFCs should be globally unique -- there should 
never be two different messages anywhere in the world at any time with 
the same Message-ID.

Different news clients (and original posting servers, if the news client 
doesn't supply its own) use different algorithms to come up with the 
Message-ID, however.  Many use some form of a combination of from address 
(either the poster's, or the posting server's) to hopefully keep 
collisions in "space" from occurring, timestamp, to keep collisions in 
time from occurring, and random number, just in case, but it's up to the 
implementation exactly what they use, as long as it's unique.

That's why the message files appear to have such strange names -- they 
are based on the Message-ID, which isn't standardized except in the 
characters it may contain and that it must be unique, and isn't really 
designed for file-naming, the use to which pan puts it.  Pan uses the 
Message-ID as a filename, however, in ordered to help keep things 
straight, since it's unique to the message and pan is designed to be able 
to track and know when it has already downloaded the same message across 
multiple servers.  (The other form of message numbering, normally 
sequential by group, is server-specific, and therefore won't help 
tracking messages between servers.)

All that said, normally, the only place these filenames appear is in 
pan's cache, which by default is pretty small, 10 MB. (The cache can be 
set larger manually, by editing preferences.xml in pan's settings dir 
directly. I run a multi-gigabyte cache, save to cache, and then sort and 
save off messages from there after they are all stored in local cache.)  
Since pan handles its cache automatically, you'll not normally see these 
files unless you go manually trawling thru the cache.

However, if as Travis suggested, if you tell pan to save the text message 
itself, not just attachments, it'll save this more or less raw text 
message.  This is nice if you want to save a text message, tho you may 
want to rename it to something more appropriate (say the subject) 
afterward.  I do this from time to time.  It's also useful on "broken" 
attachments that pan can't properly save on its own, however, as it may 
be possible to recover the attachment using other tools designed to deal 
for the purpose.  I do this too, occasionally.

So basically, if you are telling pan to save the text message not just 
the attachments, you'll get these wherever you have pan saving its 
messages.  Tell it to save attachments only, and you'll not have to worry 
about them.  Or, if you are examining pan's cache, don't worry about it, 
as pan should manage them on its own unless you've deliberately set it up 
to handle manually, as I have.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman