Provided by: imapfilter_2.2.3-1build1_i386 bug

NAME

     imapfilter_config -- imapfilter configuration file

SYNOPSIS

     $HOME/.imapfilter/config.lua

DESCRIPTION

     imapfilter(1) uses the Lua programming language as a configuration and
     extension language, therefore the configuration file is a Lua script.

     Although knowledge of Lua is not required to use imapfilter(1), it is
     nonetheless recommended, especially if one wants to extend it.

CONVENTIONS

     A brief description of the Lua values and types mentioned hereafter in
     the manual page follows:

         The nil is the type of the value ``nil'' , whose main property is to
         be different from any other value; usually it represents the absence
         of a useful value.

         The boolean is the type of the values ``true'' and ``false''.  Both
         ``nil'' and ``false'' make a condition false; any other value makes
         it true.

         The type number represents real numbers.

         The type string represents a sequence of characters and can be
         defined using single quotes, double quotes or double square brackets.

         The type table implements associative arrays, that is, arrays that
         can be indexed not only with numbers, but with any value.

         A function is a first-class value; it can be stored in variables,
         passed as argument to other functions, and returned as a result.

OPTIONS

     Program's options are set using an already initialised table named
     ``options'' , in the following manner:

         options.timeout = 120
         options.namespace = false
         options.charset = 'ISO-8859-1'

     Available options are:

     cache   When this option is enabled, parts of messages are cached locally
             in memory to avoid being downloaded more than once.  The cache is
             preserved for the current session only. This variable takes a
             boolean as a value. Default is ``true''.

     certificates
             When this option is enabled, the server certificate can be
             accepted and stored, in order to validate the authenticity of the
             server in future connections. This variable takes a boolean as a
             value. Default is ``true''.

     charset
             Indicates to the server the character set of the strings for the
             searching methods.  This variable takes a string as a value.  By
             default no character set is set, and thus plain ASCII should be
             assumed by the server.

     create  According to the IMAP specification, when trying to write a
             message to a non-existent mailbox, the server must send a hint to
             the client, whether it should create the mailbox and try again or
             not. However some IMAP servers don't follow the specification and
             don't send the correct response code to the client. By enabling
             this option the client tries to create the mailbox, despite of
             the server's response. This variable takes a boolean as a value.
             Default is ``false''.

     close   This option controls whether the currently selected mailbox is
             implicitly closed at the end of each performed operation, thus
             removing all messages that are marked deleted. This variable
             takes a boolean as a value.  Default is ``false''.

     crammd5
             When this option is enabled and the server supports the
             Challenge-Response Authentication Mechanism (specifically CRAM-
             MD5), this method will be used for user authentication instead of
             a plaintext password LOGIN.  This variable takes a boolean as a
             value.  Default is ``true''.

     expunge
             Normally, messages are marked for deletion and are actually
             deleted when the mailbox is closed.  When this option is enabled,
             messages are expunged immediately after being marked deleted.
             This variable takes a boolean as a value.  Default is ``true''.

     info    When this options is enabled, a summary of the program's actions
             is printed, while processing mailboxes.  This variable takes a
             boolean as a value.  Default is ``true''.

     keepalive
             The time in minutes before terminating and re-issuing the IDLE
             command, in order to keep alive the connection, by resetting the
             inactivity timeout of the server.  A standards compliant server
             must have an inactivity timeout of at least 30 minutes.  But it
             may happen that some IMAP servers don't respect that, or some
             intermediary network device has a shorter timeout.  By setting
             this option the above problem can be worked around. This variable
             takes a number as a value. Default is ``29'' minutes.

     namespace
             When enabled, the program gets the namespace of the user's
             personal mailboxes, and applies automatically the prefix and
             hierarchy delimiter to any mailboxes residing on the mail server;
             the user must use the `/' character as the delimiter and ``''
             (ie.  nothing) as the prefix, regardless of the folder format of
             the mail server.  This must be disabled, if the user wants to
             manually specify mailbox names (eg. because they are not part of
             the user's personal namespace mailboxes).  This variable takes
             boolean as a value.  Default is ``true''.

     starttls
             When this option is enabled and the server supports the IMAP
             STARTTLS extension, a TLS connection will be negotiated with the
             mail server in the beginning of the session.  This variable takes
             a boolean as value.  Default is ``true''.

     subscribe
             By enabling this option new mailboxes that were automatically
             created, get also subscribed; they are set active in order for
             IMAP clients to recognize them.  This variable takes a boolean as
             a value.  Default is ``false''.

     timeout
             The time in seconds for the program to wait for a mail server's
             response.  If not set, the client will block indefinitely.  This
             variable takes a number as a value.  By default no value is set.

ACCOUNTS

     Accounts are initialized using the IMAP() function, and the details of
     the connection are defined using an account table:

         myaccount = IMAP {
             server = 'imap.mail.server',
             username = 'me',
             password = 'secret',
             ssl = 'ssl3'
         }

     An account table must have the following elements:

     server  The hostname of the IMAP server to connect to.  It takes a string
             as a value.

     username
             User's name.  It takes a string as a value.

     An account table can also have the following optional elements:

     password
             User's secret keyword.  If a password wasn't supplied the user
             will be asked to enter one interactively the first time it will
             be needed.  It takes a string as a value.

     port    The port to connect to.  It takes a number as a value.  Default
             is ``143'' for imap and ``993'' for imaps.

     ssl     Forces an imaps connection and specifies the SSL/TLS protocol to
             be used.  It takes a string as a value, specifically one of:
             ``ssl2'' , ``ssl3'' , ``tls1''.

   LISTING
     The following methods can be used on an account to list mailboxes in a
     folder of an account:

     list_all(folder)
             Lists all the available mailboxes in the folder (string), and
             returns a table that contains strings, the available mailboxes,
             and a table that contains strings, the available folders.

     list_subscribed(folder)
             Lists all the subscribed mailboxes in the folder (string), and
             returns a table that contains strings, the subscribed mailboxes,
             and a table that contains strings, the subscribed folders.

     The following methods can be used on an account to list mailboxes, using
     wildcards, in a folder of an account.  The `*' wildcard, matches any
     character and the `%' matches any character except the folder delimiter,
     ie.  non-recursively:

     list_all(folder, mailbox)
             Lists all the available mailboxes in the folder (string) with the
             name mailbox (string), and returns a table that contains strings,
             the available mailboxes, and a table that contains strings, the
             available folders.  Wildcards may only be used in the mailbox
             argument.

     list_subscribed(folder, mailbox)
             Lists all the subscribed mailboxes in the folder (string) with
             the name mailbox (string), and returns a table that contains
             strings, the subscribed mailboxes, and a table that contains
             strings, the subscribed folders.  Wildcards may only be used in
             the mailbox argument.

     Examples:

         mailboxes, folders = myaccount:list_subscribed('myfolder')
         mailboxes, folders = myaccount:list_all('myfolder/mysubfolder', '*')

   MANIPULATING
     The following methods can be used to manipulate mailboxes in an account:

     create_mailbox(name)
             Creates the name (string) mailbox.

     delete_mailbox(name)
             Deletes the name (string) mailbox.

     rename_mailbox(oldname, newname)
             Renames the oldname (string) mailbox to newname (string).

     subscribe_mailbox(name)
             Subscribes the name (string) mailbox.

     unsubscribe_mailbox(name)
             Unsubscribes the name (string) mailbox.

     Examples:

         myaccount:create_mailbox('mymailbox')
         myaccount:subscribe_mailbox('mymailbox')
         myaccount:unsubscribe_mailbox('myfolder/mymailbox')
         myaccount:delete_mailbox('myfolder/mymailbox')

MAILBOXES

     After an IMAP account has been initialized, mailboxes residing in that
     account can be accessed simply as elements of the account table:

         myaccount.mymailbox

     If mailbox names don't only include letters, digits and underscores, or
     begin with a digit, an alternative form must be used:

         myaccount['mymailbox']

     A mailbox inside a folder can be only accessed by using the alternative
     form:

         myaccount['myfolder/mymailbox']

     The methods that are available for an account (eg.  list_all(),
     create_mailbox(), etc.) , are considered keywords and must not be used as
     mailbox names, and the same also applies for any string starting with an
     underscore, as they are considered reserved.

   CHECKING
     The following methods can be used to check the status of a mailbox:

     check_status()

             The check_status() method gets the current status of a mailbox,
             and returns four values of number type: the total number of
             messages, the number of recent messages, the number of unseen
             messages in the mailbox, and the next UID to be assigned to a new
             message in the mailbox.

     enter_idle()
             The enter_idle() method implements the IMAP IDLE (RFC 2177)
             extension.  By using this extension it's not necessary to poll
             the server for changes to the selected mailbox (ie.  using the
             check_status() method), but instead the server sends an update
             when there is a change in the mailbox (eg. in case of new mail).
             When the enter_idle() method has been called no more commands in
             the configuration file are executed until an update is received,
             at which point the enter_idle() method returns.  For the
             enter_idle() to work, the IDLE extension has to be supported by
             the IMAP server.  The enter_idle() method returns one value of
             type boolean: ``true'' if the IDLE extension is supported and
             there was a update in the mailbox, and ``false'' if the IDLE
             extension is not supported, in which case the method returns
             immediately.

     Examples:

         exist, unread, unseen, uidnext = myaccount.mymailbox:check_status()
         update = myaccount.mymailbox:enter_idle()

   SEARCHING
     The searching methods in this subsection can be applied to any mailbox.
     They return a special form of table, that contains the messages that
     match the searching method.  This table can be combined with other tables
     using logic theory. There are three available operations, that implement
     logical ``or'', logical ``and'' and logical ``not''.

     The logical ``or'' is implemented using the `+' operator:

         results = myaccount.mymailbox:is_unseen() +
                   myaccount.mymailbox:is_larger(100000)

     The logical ``and'' is implemented using the `*' operator:

         results = myaccount.mymailbox:is_unseen() *
                   myaccount.mymailbox:is_larger(100000)

     The logical ``not'' is implemented using the `-' operator:

         results = myaccount.mymailbox:is_unseen() -
                   myaccount.mymailbox:is_larger(100000)

     The three logical operators can be combined in the same expression. The
     logical ``and'' has higher precedence than the logical ``or'' and the
     logical ``not'', with the latter two having the same precedence, and
     parentheses may be used to change this behaviour:

         results = myaccount.mymailbox:is_unseen() +
                   myaccount.mymailbox:is_larger(100000) *
                   myaccount.mymailbox:contain_subject('test')

         results = ( myaccount.mymailbox:is_unseen() +
                     myaccount.mymailbox:is_larger(100000) ) *
                     myaccount.mymailbox:contain_subject('test')

     The returned tables of the searching methods can also be stored in
     variables and then further processed:

         unseen = myaccount.myaccount:is_unseen()
         larger = myaccount.mymailbox:is_larger(100000)
         subject = myaccount.mymailbox:contain_subject('test')
         results = unseen + larger * subject

     A composite filter that includes one or more simple rules can be defined:

         myfilter = function ()
                        return myaccount.mymailbox:is_unseen() +
                               myaccount.mymailbox:is_larger(100000) *
                               myaccount.mymailbox:contain_subject('test')
                    end

         results = myfilter()

     Composite filters can may be more dynamic by adding arguments:

         myfilter = function (mailbox, size, subject)
                        return mailbox:is_unseen() +
                               mailbox:is_larger(size) *
                               mailbox:contain_subject(subject)
                    end

         results = myfilter(myaccount.mailbox, 100000, 'test')

     It is also possible to combine the searching methods in different
     mailboxes, either at the same or different accounts, for example when the
     same actions will be executed on messages residing in different mailboxes
     or accounts.

         results = myaccount.mymailbox:is_unseen() +
                   myaccount.othermailbox:is_larger(100000) +
                   otheraccount.othermailbox:contain_subject('test')

     The following method can be used to get all messages in a mailbox:

     select_all()
             All messages.

     The following methods can be used to search for messages that are in a
     specific state:

     is_answered()
             Messages that have been answered.

     is_deleted()
             Messages that are marked for later removal.

     is_draft()
             Messages that have not completed composition.

     is_flagged()
             Messages that are flagged for urgent/special attention.

     is_new()
             Messages that are recently arrived (this session is the first to
             have been notified about these messages) and have not been read.

     is_old()
             Messages that are not recently arrived (this session is not the
             first to have been notified about these messages) and have not
             been read.

     is_recent()
             Messages that are recently arrived (this session is the first to
             have been notified about these messages).

     is_seen()
             Messages that have been read.

     is_unanswered()
             Messages that have not been answered.

     is_undeleted()
             Messages that are not marked for later removal.

     is_undraft()
             Messages that have completed composition.

     is_unflagged()
             Messages that are not flagged for urgent/special attention.

     is_unseen()
             Messages that have not been read.

     The following method can be used to search for messages that have a
     specific flag set:

     has_flag(keyword)
             Messages with the specified keyword flag (string) set.

     The following methods can be used to search for messages based on their
     size:

     is_larger(size)
             Messages that are larger than the size (number) in octets
             (bytes).

     is_smaller(size)
             Messages that are smaller than the size (number) in octets
             (bytes).

     The following methods can be used to search for messages based on their
     age:

     is_newer(age)
             Messages that are newer than the age (number) in days.

     is_older(age)
             Messages that are older than the age (number) in days.

     The following methods can be used to search for messages based on their
     arrival or sent date, in the ``day-month-year'' form, where day is the
     day of the month as a decimal number (01-31), month is the abbreviated
     month (``Jan'', ``Feb'', ``Mar'', ``Apr'', ``May'', ``Jun'', ``Jul'',
     ``Aug'', ``Sep'', ``Oct'', ``Nov'', ``Dec'') and year is the year as
     decimal number including the century (eg. 2007):

     arrived_before(date)
             messages that have arrived before the date (string), where date
             is in the ``day-month-year'' form.

     arrived_on(date)
             Messages that have arrived on the date (string), where date is in
             the ``day-month-year'' form.

     arrived_since(date)
             Messages that have arrived after the date (string), where date is
             in the ``day-month-year'' form.

     sent_before(date)
             Messages that have been sent before the date (string), where date
             is in the ``day-month-year'' form.

     sent_on(date)
             Messages that have been sent on the date (string), where date is
             in the ``day-month-year'' form.

     sent_since(date)
             Messages that have been sent after the date (string), where date
             is in the ``day-month-year'' form.

     The following methods can be used to search for messages that contain a
     specific word or phrase:

     contain_bcc(string)
             Messages that contain the string (string) in the ``Bcc'' header
             field.

     contain_cc(string)
             Messages that contain the string (string) in the ``Cc'' header
             field.

     contain_from(string)
             Messages that contain the string (string) in the ``From'' header
             field.

     contain_subject(string)
             Messages that contain the string (string) in the ``Subject''
             header field.

     contain_to(string)
             Messages that contain the string (string) in the ``To'' header
             field.

     contain_field(field, string)
             Messages that contain the string (string) in the field (string)
             header field.

     contain_body(string)
             Messages that contain the string (string) in the message body.

     contain_message(string)
             Messages that contain the string (string) in the message.

     The following methods can be used to search for messages that match a
     specific regular expression pattern.

     This way of searching is not supported by the IMAP protocol, and this
     means that what actually happens under the hood, is that the relevant
     parts of all the messages are downloaded and matched locally.  It is
     therefore recommended to use these methods with meta-searching (see
     following section), in order to narrow down the set of messages that
     should be searched, and thus minimize what will be downloaded.

     Note that due to Lua using backslash `\' as an escape character for its
     strings, one has to double backslashes in order to insert a single
     backslash inside a regular expression pattern:

     match_bcc(pattern)
             Messages that match the regular expression pattern (string) in
             the ``Bcc'' header field.

     match_cc(pattern)
             Messages that match the regular expression pattern (string) in
             the ``Cc'' header field.

     match_from(pattern)
             Messages that match the regular expression pattern (string) in
             the ``From'' header field.

     match_subject(pattern)
             Messages that match the regular expression pattern (string) in
             the ``Subject'' header field.

     match_to(pattern)
             Messages that match the regular expression pattern (string) in
             the ``To'' header field.

     match_field(field, pattern)
             Messages that match the regular expression pattern (string) in
             the field (string) header field.

     match_header(pattern)
             Messages that match the regular expression pattern (string) in
             the message header.

     match_body(pattern)
             Messages that match the regular expression pattern (string) in
             the message body.

     match_message(pattern)
             Messages that match the regular expression pattern (string) in
             the message.

     The following method can be used to search for messages using user
     queries based on the IMAP specification (RFC 3501 Section 6.4.4):

     send_query(criteria)
             Searches messages by sending an IMAP search query as described in
             the search criteria (string).

     Examples:

         results = myaccount.mymailbox:select_all()
         results = myaccount.mymailbox:is_new()
         results = myaccount.mymailbox:is_recent()
         results = myaccount.mymailbox:is_larger(100000)
         results = myaccount.mymailbox:is_older(10)
         results = myaccount.mymailbox:has_flag('MyFlag')
         results = myaccount.mymailbox:arrived_before('01-Jan-2007')
         results = myaccount.mymailbox:sent_since('01-Jan-2007')
         results = myaccount.mymailbox:contain_subject('test')
         results = myaccount.mymailbox:contain_field('Sender', 'user@host')
         results = myaccount.mymailbox:contain_body('hello world')
         results = myaccount.mymailbox:match_from('.*(user1|user2)@host')
         results = myaccount.mymailbox:send_query('ALL')

         results = myaccount['mymailbox']:is_new()
         results = myaccount['myfolder/mymailbox']:is_recent()

RESULTS

     After one of more searching methods have been applied to one or more
     mailboxes, the result contains all the necessary information, such as
     which messages matched in which mailboxes.  Using this result these
     messages can be either searched further or processed in various way.

   META-SEARCHING
     The results of the searching methods can be searched further on in the
     same way as searching is done in mailboxes.  The difference is that
     instead of doing the search in the whole mailbox, ie. in all the
     messages, it is instead done only to those messages that were returned in
     a previous search.

     Examples:

         results:match_message('^[Hh]ello world!?$')
         myaccount.mymailbox:is_new():match_body('^[Ww]orld, hello!?$')

   PROCESSING
     The processing methods are applied to the results that searching
     returned.

     The following method can be used to delete messages in a mailbox:

     delete_messages()
             Deletes the messages that matched.

     The following methods can be used to copy and move messages in a mailbox
     at the same or different accounts.  If the destination mailbox is in a
     different account than the source mailbox, then the messages are
     downloaded and then uploaded to the destination:

     copy_messages(destination)
             Copies the messages to the destination, which is a mailbox at an
             account.

     move_messages(destination)
             Moves the messages to the destination, which is a mailbox at an
             account.

     The following methods can be used to mark messages in a mailbox:

     mark_answered()
             Marks the messages as answered.

     mark_deleted()
             Marks the messages for later removal.

     mark_draft()
             Marks the messages as draft.

     mark_flagged()
             Marks the messages for urgent/special attention.

     mark_seen()
             Marks the messages as read.

     unmark_answered()
             Unmarks the messages that have been marked as answered.

     unmark_deleted()
             Unmarks the messages that have been marked for later removal.

     unmark_draft()
             Unmarks the messages that have been marked as draft.

     unmark_flagged()
             Unmarks the messages that have been marked for urgent/special
             attention.

     unmark_seen()
             Unmarks the messages that have been marked as read.

     The following methods can be used to flag messages in a mailbox. The
     standard system flags are ``\Answered'', ``\Deleted'', ``\Draft'',
     ``\Flagged'', ``\Seen'', while if the server supports it, new user
     keywords may be defined:

     add_flags(flags)
             Adds the flags (table that contains strings) to the messages.

     remove_flags(flags)
             Removes the flags (table that contains strings) from the
             messages.

     replace_flags(flags)
             Replaces the flags (table that contains strings) of the messages.

     Examples:

         results:delete_messages()
         results:copy_messages(myaccount.othermailbox)
         results:move_messages(otheraccount.mymailbox)
         results:mark_seen()
         results:unmark_flagged()
         results:add_flags({ 'MyFlag', '\\Seen' })
         results:remove_flags({ '\\Seen' })

         results:move_messages(otheraccount['myfolder/mymailbox'])

MESSAGES

     The messages that are residing in any mailbox can be also accessed, as a
     whole or in parts.  Messages can be accessed using their unique
     identifier (UID):

         myaccount.mymailbox[22]

     The UIDs of messages the user is interested in, are gained from the
     results of searching:

         results = account.INBOX:is_unread()
         for _, message in ipairs(results) do
             mailbox, uid = unpack(message)
             header = mailbox[uid]:fetch_header()
         end

   FETCHING
     The following methods can be used to fetch parts of messages.  The
     methods return a string.  The downloaded message parts are cached
     locally, so they can be reused inside the same program session:

     fetch_message()
             Fetches the header and body of the message.

     fetch_header()
             Fetches the header of the message.

     fetch_body()
             Fetches the body of the messages.

     fetch_field(field)
             Fetches the specified header field (string) of the message.

     fetch_part(part)
             Fetches the specified part (string) of the message.

     The following methods can be used to fetch details about the state of a
     message:

     fetch_flags()
             Fetches the flags of the message.  Returns a table, of strings.

     fetch_date()
             Fetches the internal date of the message.  Returns a string.

     fetch_size()
             Fetches the size of the message.  Returns a number.

     fetch_structure()
             Fetches the body structure of the message. Returns a table that
             has as keys the parts of the message, and as values a table that
             has one mandatory element, the type (string) of the part, and two
             optional elements, the size (number) and name (string) of the
             part.

     Examples:

         myaccount.mymailbox[2]:fetch_message()
         myaccount.mymailbox[3]:fetch_field('subject')
         myaccount.mymailbox[5]:fetch_part('1.1')

         myaccount['mymailbox'][7]:fetch_message()
         myaccount['myfolder/mymailbox'][11]:fetch_message()

FUNCTIONS

     The following auxiliary functions are also available for convenience:

     form_date(days)
             Forms a date in ``day-month-year'' format that the system had
             before the number of days (number), and returns it as a string.

     get_password(prompt)
             Displays the specified prompt (string), and reads a password,
             while character echoing is turned off.  Returns that password as
             a string.

     become_daemon(interval, commands)
             Detaches the program from the controlling terminal and runs it in
             the background as system daemon. The program will then repeatedly
             poll at the specified interval (number) in seconds. Each time the
             program wakes up, the commands (function) are executed.

     pipe_to(command, data)
             Executes the system's command (string) and sends the data
             (string) to the standard input channel of the subprocess. Returns
             a number, the exit status of the child process.

     pipe_from(command)
             Executes the system's command (string) and retrieves the data
             from the standard output channel of the subprocess.  Returns a
             number, the exit status of the child process, and a string, the
             output of the child process.

     regex_search(pattern, string)
             Implements Perl-compatible regular expressions (PCRE). The
             pattern (string) is a PCRE pattern. The string (string) is the
             subject string in which the pattern is matched against. Returns
             at least a boolean, that denotes if the match was successful, and
             any captures which are of string type.  Note that due to Lua
             using backslash `\' as an escape character for its strings, one
             has to double backslashes in order to insert a single backslash
             inside a regular expression pattern:

     Examples:

         date = form_date(14)
         password = get_password('Enter password: ')
         become_daemon(600, myfunction)
         status = pipe_to('mycommandline', 'mydata')
         status, data = pipe_from('mycommandline')
         success, capture = regex_search('^[PpCcRrEe]: (\\w)$', 'mystring')

EXAMPLES

     See samples/config.lua and samples/extend.lua in the source code
     distribution.

ENVIRONMENT

     HOME    User's home directory.

SEE ALSO

     imapfilter(1)

BUGS

     Since version 2.2, a different format is used for the returned structures
     of the searching methods, due to the introduction of multiple mailbox
     searching and meta-searching, and thus any configuration files that rely
     on them should be updated.  Consequently, the processing and fetching
     methods have been also enhanced and the relevant documentation modified,
     and while these changes are backwards compatible, an update of the
     configuration file is still recommended.

     Since version 2.0, the configuration file format has changed.  The new
     format is not backwards compatible, and thus it should not be mixed with
     the old format. Nevertheless, configuration files that employ the old,
     and now deprecated, format can still be read and executed as before.