imapfilter/samples/extend.lua
2012-05-23 20:44:31 +02:00

123 lines
3.8 KiB
Lua

--
-- This file contains examples on how IMAPFilter can be extended using
-- the Lua programming language.
--
-- IMAPFilter can be detached from the controlling terminal and run in
-- the background as a system daemon.
--
-- The auxiliary function become_daemon() is supplied for conveniency.
-- The following example puts imapfilter in the background and runs
-- endlessly, executing the commands in the forever() function and
-- sleeping for 600 seconds between intervals:
function forever()
results = myaccount.mymailbox:is_old()
results:move_messages(myaccount.myothermailbox)
end
become_daemon(600, forever)
-- IMAPFilter can take advantage of all those filtering utilities that
-- are available and use a wide range of heuristic tests, text analysis,
-- internet-based realtime blacklists, advanced learning algorithms,
-- etc. to classify mail. IMAPFilter can pipe a message to a program
-- and act on the message based on the program's exit status.
--
-- The auxiliary function pipe_to() is supplied for conveniency. For
-- example if there was a utility named "bayesian-spam-filter", which
-- returned 1 when it considered the message "spam" and 0 otherwise:
all = myaccount.mymailbox:select_all()
results = Set {}
for _, mesg in ipairs(all) do
mbox, uid = table.unpack(mesg)
text = mbox[uid]:fetch_message()
if (pipe_to('bayesian-spam-filter', text) == 1) then
table.insert(results, mesg)
end
end
results:delete_messages()
-- One might want to run the bayesian filter only in those parts (attachments)
-- of the message that are of type text/plain and smaller than 1024 bytes.
-- This is possible using the fetch_structure() and fetch_part() functions:
all = myaccount.mymailbox:select_all()
results = Set {}
for _, mesg in ipairs(all) do
mbox, uid = table.unpack(mesg)
structure = mbox[uid]:fetch_structure()
for partid, partinf in pairs(structure) do
if partinf.type:lower() == 'text/plain' and partinf.size < 1024 then
part = mbox[uid]:fetch_part(partid)
if (pipe_to('bayesian-spam-filter', part) == 1) then
table.insert(results, mesg)
break
end
end
end
end
results:delete_messages()
-- Messages can be appended to a mailbox. One can fetch a message from a
-- mailbox, optionally process it, and then upload it to the same or different
-- mailbox, at the same or different mail servers. In the following example a
-- header field is added to all messages, and the processed messages are then
-- appended to a different mailbox.
all = myaccount.mymailbox:select_all()
for _, mesg in ipairs(all) do
mbox, uid = table.unpack(mesg)
header = mbox[uid]:fetch_header()
body = mbox[uid]:fetch_body()
message = header:gsub('[\r\n]+$', '\r\n') ..
'My-Header: My-Content\r\n' .. '\r\n' .. body
myaccount.myothermaibox:append_message(message)
end
-- Passwords could be extracted during execution time from an encrypted
-- file.
--
-- The file is encrypted using the openssl(1) command line tool. For
-- example the "passwords.txt" file:
--
-- secret1
-- secret2
--
-- ... is encrypted and saved to a file named "passwords.enc" with the
-- command:
--
-- $ openssl bf -in passwords.txt -out passwords.enc
--
-- The auxiliary function pipe_from() is supplied for conveniency. The
-- user is prompted to enter the decryption password, the file is
-- decrypted and the account passwords are set accordingly:
status, output = pipe_from('openssl bf -d -in ~/passwords.enc')
_, _, password1, password2 = string.find(output, '([%w%p]+)\n([%w%p]+)')
account1 = IMAP {
server = 'imap1.mail.server',
username = 'user1',
password = password1
}
account2 = IMAP {
server = 'imap2.mail.server',
username = 'user2',
password = password2
}