[REBOL] Re: POP-3 command TOP not supported, what to do?
From: kevin:sunshinecable at: 5-Feb-2001 17:02
On Sun, 4 Feb 2001, Martin Rommel wrote:
> Hello list,
> the implementation of the POP-3 protocol in Rebol seems not to support the
> command TOP which is used to retrieve only the header of an email from the
> server (and possibly a specified number of lines of the message, see RFC
> 1939). <clip>
> Why doesn't the import-email function just have a modifier to allow only
> downloading the header without the content of the message.
<clip>
> How to do that in rebol? Has anybody ever tried that?
> Any help is appreciated!
Hi Martin,
This was discussed ages ago (summer of '99) between Allen K, Bo, and
myself. When it was brought up again last year, I summarized the earlier
conclusions and tossed the challenge to Jeff at REBOL who had a couple of
free minutes that afternoon and whipped up a solution. This change has
not yet been included into REBOL's stock POP3 protocol, but IMHO it should
be.
I originally suggested a refinement for 'read.
Here's what Jeff came up with... It works very well.
Hope it helps you.
Cheers,
Kev
[insert original message...]
Jeff ([jeff--rebol--com]) wrote:
Well, that's pretty simple. It would be a little more difficult to
have a different refinement for read with pop-- but pop can pretty
easily be modified to return the top info, or store the info
similarly to the way we had the LIST command do it. Perhaps the URL
could be a little different:
x: open pop://user:[pass--server]/summary
Will cause x/locals to get a field that contains the TOP
info. Of course, its up to you to parse the TOP info afterwards.
So... change the number in top-check block to how ever many lines
of context you want. Here you go:
-------------------------------------------------------
REBOL [
Title: "A slightly modified version of pop"
]
make Root-Protocol [
{Communicate with POP. This protocol is block oriented not
string oriented.}
port-flags: system/standard/port-flags/pass-thru
open-check: [ ; port is bound to confirm frame
none "+OK"
["USER" port/user] "+OK"
["PASS" port/pass] "+OK"
]
close-check: ["QUIT" "+OK"]
write-check: [none "+OK"]
stat-check: ["STAT" "+OK"]
list-check: ["LIST" "+OK"]
top-check: [reform ["TOP" num 10] "+OK"]
open: func [port /total/tblock/summary][
open-proto port
port/state/tail: second total: load net-utils/confirm port/sub-port stat-check
port/locals: make object! [
total-size: third total
net-utils/confirm port/sub-port list-check
sizes: load read-til-dot port make string! 100
summary: either port/target = "summary" [
tblock: system/words/copy []
repeat num port/state/tail [
net-utils/confirm port/sub-port reduce bind top-check 'num
append tblock read-til-dot port make string! 100
]
tblock
][none]
msg-nums: make block! port/state/tail
repeat n port/state/tail [append msg-nums n] ; lookaside index
]
port/state/index: 0 ; a zero based index
]
read-til-dot: func [port buf][
while [(line: system/words/pick port/sub-port 1) <> "."] [
insert tail buf line
insert tail buf newline
]
buf
]
read-message: func [
"Read a message from the POP server"
port
n [integer!]
/local buf line
][
insert port/sub-port reform [
"RETR" system/words/pick port/locals/msg-nums port/state/index + n]
net-utils/confirm port/sub-port write-check
read-til-dot port buf: make string! 1024 ; guess at size
]
pick: func [
"Read the Nth message from the POP port"
port
][
read-message port 1
]
copy: func [
"Copy a set of messages into a block"
port
/local msgs n
][
msgs: make block! port/state/num
repeat n port/state/num [
append msgs read-message port n
]
msgs
]
remove: func [
"Remove the current message"
port
][
while [ port/state/num > 0 ][
insert port/sub-port reform [
"DELE" system/words/pick port/locals/msg-nums port/state/index + 1]
net-utils/confirm port/sub-port write-check
system/words/remove at port/locals/msg-nums port/state/index + 1
port/state/tail: port/state/tail - 1
port/state/num: port/state/num - 1
]
port
]
net-utils/net-install POP self 110
]
