SYNOPSIS

        mhthread [options] +folder
        mhthread [options] /path/to/folder

options accepted: [-debug] [-no-write] [-fast] [-lock]

DESCRIPTION

This will thread an MH folder. It re-orders the messages (as sortm(1) would do), and annotates each one with a new header, ``X-MH-Thread-Markup'', which can be displayed by scan(1).

Together, this results in the messages being displayed in ``threaded'' order, as in trn(1) or mutt(1).

Sequences will be rewritten appropriately. The folder will also be ``packed'', as if 'folder -pack' had been run; see folder(1).

RESULTS

Here's some sample output from scan(1), after threading the folder:

  430  03/23 mathew              3  [Asrg] Re: [OffTopic - NNTP]
  431  03/23 Kee Hinckley        5  |- [Asrg] Re: [OffTopic - NNTP]
  432 -03/23 Chuq Von Rospach   11  | |- Parameters for success? (was Re: [A
  433  03/23 To:Chuq Von Rospa   4  | | \- Re: Parameters for success? (was 
  434  03/23 Matt Sergeant       3  | \- Re: [Asrg] Re: [OffTopic - NNTP]
  435  03/23 Chuq Von Rospach    7  \- Re: [Asrg] Re: [OffTopic - NNTP]

OPTIONS

-fast
Use an on-disk cache to speed up operation.

-lock
Use a folder-wide lock-file to synchronize access to folders, so that multiple processes will not stomp on each other's changes or cause folder corruption. If you use this, you should ensure that you also use a locking version of other tools, such as the lockedrcvstore script that comes with ExMH (typical location: /usr/lib/exmh*/misc/lockedrcvstore).

-no-write
Do not rewrite the messages; instead, output a line for each message noting the actions that would be taken.

-debug
Output debugging info to stderr.

Note that options will also be read from the mhthread entry in your .mh_profile file, in traditional MH style.

INSTALLATION FOR SCAN

To display the results in scan(1) output, use something like the following for the subject-display part of the scan.form file:

  %(decode{x-mh-thread-markup})%(decode{subject})

If you do not have a ``scan.form'' file of your own, you will need to set it up. This functionality is accessed using the -form or -format switches to the scan(1) command. To use this, copy the /etc/nmh/scan.default file to your ~/Mail dir and modify it with the above line, then add

  scan: -form scan.form

to your ~/.mh_profile.

INSTALLATION FOR EXMH

Add the following function to your ~/.tk/exmh/user.tcl file:

  proc Folder_Thread {} {
    global exmh
    Background_Wait
    Exmh_Status "Threading folder..." blue
    if {[Ftoc_Changes "Thread"] == 0} then {
      if {[catch {MhExec mhthread +$exmh(folder)} err]} {
          Exmh_Status $err error
      } else {
        # finish off by using the ExMH packing logic to redisplay folder
        Folder_Pack
        # then show the first unseen message
        Msg_ShowUnseen
      }
    }
  }

Next, you need to rebuild the tclIndex file. Run tclsh and type:

  auto_mkindex ~/.tk/exmh *.tcl

Now add a button to run this function. To do this, you must exit ExMH first, then edit the ~/.exmh/exmh-defaults file and add these files at the top of the file:

  *Fops.ubuttonlist: thread
  *Fops.thread.text: Thread
  *Fops.thread.command: Folder_Thread

Restart ExMH, and there should be a new button marked Thread on the folder button-bar. Press this to re-thread the current folder.

NOTES

The threading algorithm uses the In-Reply-To, Message-Id and References headers. Thanks to JWZ for guidance, in the form of his page on threading at http://www.jwz.org/doc/threading.html.

The 'X-MH-Thread-Markup' headers are encoded using RFC-2047 encoding, using 'no-break space' characters for whitespace, as otherwise MH's scan(1) format code will strip them. Here's an example of the results:

  X-MH-Thread-Markup: =?US-ASCII?Q?=a0=a0=a0=a0=5c=2d=a0?=

TODO

dealing with private sequences (stored in .mh_profile); limiting displayed thread-depth to keep UI readable (so far has not been a problem).

BUGS

duplicate messages will always be shuffled in order each time mhthread is run, due to handling of identical Message-Ids.

DOWNLOAD

Latest version can be found at http://jmason.org/software/mhthread/ .

AUTHOR

Justin Mason, jm dash mhthread dash nospam at jmason dot org

VERSION

version = 1.5, Apr 25 2003 jm