filter - filter incoming messages before adding to mailbox

     filter [-q] [-v] [-l] [-o output] [-f rules-file]
     filter [-n] [-f rules-file]
     filter [-r] [-o output] [-f rules-file]
     filter [-c] [-s] [-o output] [-f rules-file]
     filter [-c] [-S] [-o output] [-f rules-file]

     Filter uses a set of selection  rules  to  process  incoming
     mail  messages.   The  format  for  the  rules,  located  in
     $HOME/.elm/filter-rules, is;

             rule  ::=  if  (expression)  then  action

     where expression is:

             expression  ::=  {  not  }  condition  expr2

             expr2  ::=  NULL  |  and  condition  expr2

             condition  ::=  field  relationship  value
                        ::=  lines  relop  numvalue
     or                 ::=  always

     These further break down as:

             field  ::=  from  |  subject  |  to  |  lines | sender

             relationship  ::=  =  |  !=

             relop  ::=  =  |  !=  |  <  |  >  |  <=  |  >=

             value  ::=  any  quoted  string

             numvalue  ::=  any  integer  value

     Action can be any of:

             save  foldername
             savecopy foldername
             execute  command
             executec  command
             forward  address

     For further information about the rules language, please see
     The Elm Filter Guide.

     The flags the filter program understands are;

     -c        Clear logs.  If this flag is used, the  log  files
               will  be  removed after being summarized by either
               "-s" or "-S" (see below).

     -f rules-file
               Get rules from specified file instead  of  default

     -l        Log actions only.  Do not  log  information  about
               mailed messages.

     -n        Not really.  Output what  would  happen  if  given
               message from standard input, but don't actually do
               anything with it.

     -o file   Redirect stdout messages to the specified file  or
               device.    Logging   of   filter  actions  is  not
               affected.  (This is added to more gracefully  deal
               with changes in the file system (since sendmail is
               quite picky about modes of files being  redirected

     -q        Quiet.  Do not log filtering actions.

     -r        Rules.  List the rules currently being used.

     -s        Summarize.  List a summary of the message  filter-
               ing log.

     -S        This is the same as `-s' but includes  message-by-
               message information additionally.

     -v        Verbose.  Give output on  standard  out  for  each
               message  filtered.   Useful  to have redirected to
               ``/dev/console'' and such.  (see -o too).

     Elm Development Group

     $HOME/.elm/filter-rules     Default rules file
     $HOME/.elm/filterlog        A log of what has been done
     $HOME/.elm/filtersum        A summary of what has been done
     /etc/passwd             Used to get users home directory

     The Elm Filter Guide
     readmsg(1L), elm(1L), mail(1), mailx(1), sendmail(1,8)

     Not really smart about pattern matching.

     Syd Weinstein  elm@DSI.COM    (dsinc!elm)

     Copyright 1988-1992 by The USENET Community Trust
     Derived from Elm 2.0,  Copyright 1986, 1987 by Dave Taylor