[Pan-users] Re: Re: download multiple binaries

[Duncan]

riccardo ferraro posted
<address@hidden>, excerpted below,  on
Sun, 06 Feb 2005 09:41:35 +0100:

> I've tried the manual/decode/save, but it saves only the first file, i.e.
> the first part of the multipart message. After the operation is completed,
> a little icon resembling a disk appear near the names of ALL files which 
> are part of the multipart,  as if I should have all files saved on my hd.
> The point is that only tha first file is present, and the other parts are 
> missing.

OK, I think I see where the confusion is now...

Take a look in preferences > header pane > other settings > show complete
multipart posts as a single article.

That's probably checked, so complete multipart posts appear as one post,
not as many, while incomplete multipart posts will show all available
parts, typically many, but it's still defined as incomplete because one
or more parts are missing so it's showing all the parts that are there
instead of just the single "folded" entry that hides each individual part.

Uncheck that option and OK (or apply), then go look at your group.  You'll
see that the formerly folded many parts of the complete posts now show.
However, when you save the attachment, you normally only get one (with
some exceptions I'll ignore for now). That's because each part of the
multipart holds a part of the (single) file.  Each one does NOT contain
its own file.

Now back to the incomplete posts.  Again, each part only contains a piece
of the single attached file.  If you do a manual save, PAN will decode
what it has into a single file, but pieces presumably from the center of
it will be missing.  If it's an mpeg, which can recover when parts are
missing or garbage, it'll play the first part, you may see some pixelation
and a scene jerk as it skips over a missing part, and the movie will
continue with the next part that was there to save, all in the same file. 
If it's a fully compressed format, the missing section won't allow the
decompression to occur without error, so the file will be useless.  Still,
it's only a single file, from one single (incomplete) multipart post, just
as the complete multipart post only formed a single file even tho there
were many parts.

There are, of course, occasions where a very large file, say a CD or DVD
ISO on the order of hundreds of megabytes or even multiple gigabytes, may
be pre-split before posting, perhaps into parts of 10MB each.  These parts
will usually have a filename with the extension consisting of a number,
say Mandrake-10.1-CD3.iso.030, for the thirtieth part of that presplit ISO
file.  These parts will need to be recombined outside of PAN, perhaps
using a redirected cat command under bash:

cat Mandrake-10.1-CD3.iso.* > Mandrake-10.1-CD3.iso

However, this isn't what we mean by a multipart post in Internet news
terms.  What we mean by a multipart post would be if the poster had
configured his news poster to post parts no larger than 4MB, in which case
those 10MB *.iso.### files will be further split for posting into a
multipart post, with each file being posted as a minimum of three
individual post parts, likely each with the filename displayed in the
subject as "Mandrake-10.1-CD3.iso.030 [01/03]".

If all parts of those three are available and PAN is configured to display
complete multiparts as a single entry, it will simply show the first part,
(01/03) but will have the green "complete" icon next to it.  If PAN is
configured to show complete multiparts as the individual parts, it will
display part 01/03 with parts 02 and 03 shown below it as if they were
subthread replies.  If say part 02 is missing, PAN will display it as an
incomplete post, which always shows all available parts, and will
therefore show part 01 with part 03 below it (part 02 being missing) as if
it were subthreaded.  That does /not/ mean they contain two separate
attachments, but rather that at least one part is missing.  Thus, if you
force a manual save, it will save as just a single file,
Mandrake-10.1-CD3.iso.030, as if all parts had been there, but the file
will be smaller because the middle of it is missing.

As I briefly mentioned above, however, while few news veterans post more
than a single file attached to a post, multipart or not, and will
generally put the attached filename in the subject line, often newbies
will post multiple attachments, particularly jpeg images, in the same post
(which will therefore not generally have the filenames in the title, tho
it may have the series name).  In this case, saving the attachments,
complete or not, may produce several files.  Similarly, on occasion PAN
parses the subject line wrong and believes a series of posts are actually
a single multipart post.  Again, saving the attachments, whether PAN
thinks that multipart post is complete or not, will result in multiple
files.

Make a bit more sense now or did I just make the confusion worse? <g>

-- 
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 in
http://www.linuxdevcenter.com/pub/a/linux/2004/12/22/rms_interview.html