+++ /dev/null
-Jon Steinhart's (jon@fourwinds.com) External Program Hooks
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-This blurb describes a changes to nmh that implement an interface
-to external programs. This interface is different than the limited
-interface provided by things like the rmmproc context entry.
-
-
-Why Did I Do This?
-~~~~~~~~~~~~~~~~~~
-
-I'm working on a project (grokmail) that will get released via GPL sometime
-soon. This project keeps a database synchronized with the messages in the
-mail system. New functionality is built on top of this database. This
-functionality allows fast searching, and searching based on interest
-criteria. The latter can be used for spam filtering.
-
-The changes to nmh allow external programs to be run whenever a message is
-added to a folder, removed from a folder, or refiled. The changes are
-implemented in a general way so that it can be used for other purposes than
-mine.
-
-What Are The Changes?
-~~~~~~~~~~~~~~~~~~~~~
-
-The changes add four new profile components:
-
-add-hook: This is the full pathname of a program that is invoked
- whenever a message is added to a folder. The program
- is passed one argument which is the full pathname of the
- message file. The program is executed after the message
- is written so that it can act upon that message.
-
-del-hook: This is the full pathname of a program that is invoked
- whenever a message is deleted from a folder. The program
- is passed one argument which is the full pathname of the
- message file. The program is executed before the message
- is written so that it can act upon that message.
-
-ref-hook: This is the full pathname of a program that is invoked
- whenever a message is refiled. The program is passed two
- arguments: the first is the full pathname of the original
- message file, the second is the full pathname of the final
- message file. The program is executed after the message
- is written.
-
-msg-hook: This is a text message that is output if the execution of
- one of the external hook programs fails. There is a built-in
- default message if none is specified.
-
-The definition of refiling is a bit tricky. The refile hook is executed if a
-message is moved from one place to another. So, for example, the command
-
- refile -link
-
-causes the add hook to be executed, not the refile hook, because a new message
-is created, the old one isn't moved.
-
-These changes affect the following commands:
-
-burst: The add hook is executed for messages burst from a digest, and
- for the table of contents if -inplace is specified. The delete
- hook is executed for the original message if -inplace is
- specified. The refile hook is executed for messages that are
- moved.
-
-folder: The refile hook is executed for -pack.
-
-inc: The add hook is executed when messages are incorporated.
-
-refile: Either the add or refile hooks are executed.
-
-rmf: The delete hook is executed when messages are deleted.
-
-rmm: The delete hook is executed when messages are deleted.
-
-sortm: The refile hook is executed for each message moved. Note that
- a magic temporary message number of 2147483647 is used to hold
- messages as they are being shuffled.
-
-rcvstore: The add hook is executed when messages are stored.
-
-mhstore: The add hook is executed when messages are stored.
-
-Did I Do This Correctly?
-~~~~~~~~~~~~~~~~~~~~~~~~
-
-Well, sort of. This all works, but I'm not really happy with it. The issue
-is that an examination of the nmh code shows that message handling is scattered
-all over the place. Although there are library routines such as folder_addmsg
-and folder_delmsgs, they are not used consistently. Long term, I think that it
-would be better to make all message handling go through the same choke points.
-
-Also, I added a function to run the external programs. This sort of stuff is
-also scattered around the nmh code, for example in the code to run the rmmproc.
-Again, I'd like to make this more consistent in the long term.
-
-What Files Did I Change?
-~~~~~~~~~~~~~~~~~~~~~~~~
-uip/
- burst.c
- inc.c
- refile.c
- rmf.c
- sortm.c
-
-sbr/
- folder_addmsg.c
- folder_delmsgs.c
- folder_pack.c
- ext_hook.c (new file)
projects / mmh / blobdiff