imap4 - imap client

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# imap4(n) 0.5.3 tcllib "imap client"

## Name

imap4 - imap client-side tcl implementation of imap protocol

## Synopsis

- package require Tcl 8.5
- package require imap4 ?0.5.3?

- ::imap4::open hostname ?port?
- ::imap4::starttls chan
- ::imap4::login chan user pass
- ::imap4::folders chan ?-inline? ?mboxref? ?mboxname?
- ::imap4::select chan ?mailbox?
- ::imap4::examine chan ?mailbox?
- ::imap4::fetch chan range ?-inline? ?attr ...?
- ::imap4::noop chan
- ::imap4::check chan
- ::imap4::folderinfo chan ?info?
- ::imap4::msginfo chan msgid ?info? ?defval?
- ::imap4::mboxinfo chan ?info?
- ::imap4::isableto chan ?capability?
- ::imap4::create chan mailbox
- ::imap4::delete chan mailbox
- ::imap4::rename chan oldname newname
- ::imap4::subscribe chan mailbox
- ::imap4::unsubscribe chan mailbox
- ::imap4::search chan expr ?...?
- ::imap4::close chan
- ::imap4::cleanup chan
- ::imap4::debugmode chan ?errormsg?
- ::imap4::store chan range data flaglist
- ::imap4::expunge chan
- ::imap4::copy chan msgid mailbox
- ::imap4::logout chan

## Description

The imap4 library package provides the client side of the Internet Message Access Protocol (IMAP) using standard sockets or secure connection via TLS/SSL. The package is fully implemented in Tcl.

This document describes the procedures and explains their usage.

## PROCEDURES

This package defines the following public procedures:

::imap4::open hostname ?port?

  Open a new IMAP connection and initalize the handler, the imap communication channel (handler) is returned.

  hostname - mail server

  port - connection port, defaults to 143

  The namespace variable ::imap4::use_ssl can be used to establish to a secure connection via TSL/SSL if set to true. In this case default connection port defaults to 993.

  Note: For connecting via SSL the Tcl module tls must be already loaded otherwise an error is raised.

          package require tls              ; # must be loaded for TLS/SSL
          set ::imap4::use_ssl 1           ; # request a secure connection
          set chan [::imap4::open $server] ; # default port is now 993

::imap4::starttls chan

  Use this when tasked with connecting to an unsecure port which must be changed to a secure port prior to user login. This feature is known as STARTTLS.

::imap4::login chan user pass

  Login using the IMAP LOGIN command, 0 is returned on successful login.

  chan - imap channel

  user - username

  pass - password

::imap4::folders chan ?-inline? ?mboxref? ?mboxname?

  Get list of matching folders, 0 is returned on success.

  Wildcards '*' as '%' are allowed for mboxref and mboxname, command ::imap4::folderinfo can be used to retrieve folder information.

  chan - imap channel

  mboxref - mailbox reference, defaults to ""

  mboxname - mailbox name, defaults to "*"

  If -inline is specified a compact folderlist is returned instead of the result code. All flags are converted to lowercase and leading special characters are removed.

      {{Arc08 noselect} {Arc08/Private {noinferiors unmarked}} {INBOX noinferiors}}

::imap4::select chan ?mailbox?

  Select a mailbox, 0 is returned on success.

  chan - imap channel

  mailbox - Path of the mailbox, defaults to INBOX

  Prior to examine/select an open mailbox must be closed - see: ::imap4::close.

::imap4::examine chan ?mailbox?

  "Examines" a mailbox, read-only equivalent of ::imap4::select.

  chan - imap channel

  mailbox - mailbox name or path to mailbox, defaults to INBOX

  Prior to examine/select an open mailbox must be closed - see: ::imap4::close.

::imap4::fetch chan range ?-inline? ?attr ...?

  Fetch attributes from messages.

  The attributes are fetched and stored in the internal state which can be retrieved with command ::imap4::msginfo, 0 is returned on success. If -inline is specified, alle records are returned as list in order as defined in the attr argument.

  chan - imap channel

  range - message index in format FROM:TO

  attr - imap attributes to fetch

  Note: If FROM is omitted, the 1st message is assumed, if TO is ommitted the last message is assumed. All message index ranges are 1-based.

::imap4::noop chan

  Send NOOP command to server. May get information as untagged data.

  chan - imap channel

::imap4::check chan

  Send CHECK command to server. Flush to disk.

  chan - imap channel

::imap4::folderinfo chan ?info?

  Get information on the recently selected folderlist. If the info argument is omitted or a null string, the full list of information available for the mailbox is returned.

  If the required information name is suffixed with a ? character, the command returns true if the information is available, or false if it is not.

  chan - imap channel

  info - folderlist options to retrieve

  Currently supported options: delim - hierarchy delimiter only, match - ref and mbox search patterns (see ::imap4::folders), names - list of folder names only, flags - list of folder names with flags in format { {name {flags}} ... } (see also compact format in function ::imap4::folders).

      {{Arc08 {{\NoSelect}}} {Arc08/Private {{\NoInferiors} {\UnMarked}}} {INBOX {\NoInferiors}}}

::imap4::msginfo chan msgid ?info? ?defval?

  Get information (from previously collected using fetch) from a given msgid. If the 'info' argument is omitted or a null string, the list of available information options for the given message is returned.

  If the required information name is suffixed with a ? character, the command returns true if the information is available, or false if it is not.

  chan - imap channel

  msgid - message number

  info - imap keyword to retrieve

  defval - default value, returned if info is empty

  Note: All message index ranges are 1-based.

::imap4::mboxinfo chan ?info?

  Get information on the currently selected mailbox. If the info argument is omitted or a null string, the list of available information options for the mailbox is returned.

  If the required information name is suffixed with a ? character, the command returns true if the information is available, or false if it is not.

  chan - imap channel

  opt - mailbox option to retrieve

  Currently supported options: EXISTS (noof msgs), RECENT (noof 'recent' flagged msgs), FLAGS

  In conjunction with OK: PERMFLAGS, UIDNEXT, UIDVAL, UNSEEN

  Div. states: CURRENT, FOUND, PERM.

          ::imap4::select $chan INBOX
          puts "[::imap4::mboxinfo $chan exists] mails in INBOX"

::imap4::isableto chan ?capability?

  Test for capability. It returns 1 if requested capability is supported, 0 otherwise. If capability is omitted all capability imap codes are retured as list.

  chan - imap channel

  info - imap keyword to retrieve

  Note: Use the capability command to ask the server if not already done by the user.

::imap4::create chan mailbox

  Create a new mailbox.

  chan - imap channel

  mailbox - mailbox name

::imap4::delete chan mailbox

  Delete a new mailbox.

  chan - imap channel

  mailbox - mailbox name

::imap4::rename chan oldname newname

  Rename a new mailbox.

  chan - imap channel

  mailbox - old mailbox name

  mailbox - new mailbox name

::imap4::subscribe chan mailbox

  Subscribe a new mailbox.

  chan - imap channel

  mailbox - mailbox name

::imap4::unsubscribe chan mailbox

  Unsubscribe a new mailbox.

  chan - imap channel

  mailbox - mailbox name

::imap4::search chan expr ?...?

  Search for mails matching search criterions, 0 is returned on success.

  chan - imap channel

  expr - imap search expression

  Notes: Currently the following search expressions are handled:

  Mail header flags: all mail header entries (ending with a colon ":"), like "From:", "Bcc:", ...

  Imap message search flags: ANSWERED, DELETED, DRAFT, FLAGGED, RECENT, SEEN, NEW, OLD, UNANSWERED, UNDELETED, UNDRAFT, UNFLAGGED, UNSEEN, ALL

  Imap header search flags: BODY, CC, FROM, SUBJECT, TEXT, KEYWORD, BCC

  Imap conditional search flags: SMALLER, LARGER, ON, SENTBEFORE, SENTON, SENTSINCE, SINCE, BEFORE (not implemented), UID (not implemented)

  Logical search conditions: OR, NOT

      ::imap4::search $chan larger 4000 seen
      puts "Found messages: [::imap4::mboxinfo $chan found]"
      Found messages: 1 3 6 7 8 9 13 14 15 19 20

::imap4::close chan

  Close the mailbox. Permanently removes \Deleted messages and return to the AUTH state.

  chan - imap channel

::imap4::cleanup chan

  Destroy an IMAP connection and free the used space. Close the mailbox. Permanently removes \Deleted messages and return to the AUTH state.

  chan - imap channel

::imap4::debugmode chan ?errormsg?

  Switch client into command line debug mode.

  This is a developers mode only that pass the control to the programmer. Every line entered is sent verbatim to the server (after the addition of the request identifier). The ::imap4::debug variable is automatically set to '1' on enter.

  It's possible to execute Tcl commands starting the line with a slash.

  chan - imap channel

  errormsg - optional error message to display

::imap4::store chan range data flaglist

  Alters data associated with a message in the selected mailbox.

  chan - imap channel

  range - message index in format FROM:TO

  flaglist - Flags the data operates on.

  data - The currently defined data items that can be stored are shown below. Note that all of these data types may also be suffixed with ".SILENT" to suppress the untagged FETCH response.

  FLAGS

    Replace the flags for the message (other than \Recent) with the flaglist.

  +FLAGS

    Add the flags in flaglist to the existing flags for the message.

  -FLAGS

    Remove the flags in flaglist to the existing flags for the message.

  For example:

      	::imap4::store $chan $start_msgid:$end_msgid +FLAGS "Deleted"

::imap4::expunge chan

  Permanently removes all messages that have the \Deleted flag set from the currently selected mailbox, without the need to close the connection.

  chan - imap channel

::imap4::copy chan msgid mailbox

  Copies the specified message (identified by its message number) to the named mailbox, i.e. imap folder.

  chan - imap channel

  msgid - message number

  mailbox - mailbox name

::imap4::logout chan

  Informs the server that the client is done with the connection and closes the network connection. Permanently removes \Deleted messages.

  A new connection will need to be established to login once more.

  chan - imap channel

## EXAMPLES

        set user myusername
        set pass xtremescrt
        set server imap.test.tld
        set FOLDER INBOX
        # Connect to server
        set imap [::imap4::open $server]
        ::imap4::login $imap $user $pass
        ::imap4::select $imap $FOLDER
        # Output all the information about that mailbox
        foreach info [::imap4::mboxinfo $imap] {
            puts "$info -> [::imap4::mboxinfo $imap $info]"
        }
        # fetch 3 records inline
        set fields {from: to: subject: size}
        foreach rec [::imap4::fetch $imap :3 -inline {*}$fields] {
            puts -nonewline "#[incr idx])"
            for {set j 0} {$j<[llength $fields]} {incr j} {
                puts "\t[lindex $fields $j] [lindex $rec $j]"
            }
        }
        # Show all the information available about the message ID 1
        puts "Available info about message 1: [::imap4::msginfo $imap 1]"
        # Use the capability stuff
        puts "Capabilities: [::imap4::isableto $imap]"
        puts "Is able to imap4rev1? [::imap4::isableto $imap imap4rev1]"
        # Cleanup
        ::imap4::cleanup $imap

## TLS Security Considerations

This package uses the TLS package to handle the security for https urls and other socket connections.

Policy decisions like the set of protocols to support and what ciphers to use are not the responsibility of TLS, nor of this package itself however. Such decisions are the responsibility of whichever application is using the package, and are likely influenced by the set of servers the application will talk to as well.

For example, in light of the recent POODLE attack discovered by Google many servers will disable support for the SSLv3 protocol. To handle this change the applications using TLS must be patched, and not this package, nor TLS itself. Such a patch may be as simple as generally activating tls1 support, as shown in the example below.

        package require tls
        tls::init -tls1 1 ;# forcibly activate support for the TLS1 protocol
        ... your own application code ...

## REFERENCES

Mark R. Crispin, "INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1", RFC 3501, March 2003, http://www.rfc-editor.org/rfc/rfc3501.txt

OpenSSL, http://www.openssl.org/

## Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category imap4 of the Tcllib Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.

When proposing code changes, please provide unified diffs, i.e the output of diff -u.

Note further that attachments are strongly preferred over inlined patches. Attachments can be made by going to the Edit form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar. Only a small part of rfc3501 implemented.

## See Also

ftp, http, imap, mime, pop3, tls

## Keywords

email, imap, internet, mail, net, rfc3501, ssl, tls

## Category

Networking