filter

     NAME
          filter - filter incoming messages before adding to mailbox

     SYNOPSIS
          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]

     DESCRIPTION
          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:

                  delete
                  save  foldername
                  savecopy foldername
                  execute  command
                  executec  command
                  forward  address
                  leave

          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
                    $HOME/.elm/filter-rules

          -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
                    into.))

          -q        Quiet.  Do not log filtering actions.

          -r        Rules.  List the rules currently being used.

          -s        Summarize.  List a summary of the message
                    filtering 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).

     AUTHOR
          Elm Development Group

     FILES
          $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

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

     COMMENTS
          Not really smart about pattern matching.

     BUG REPORTS TO
          Syd Weinstein  elm@DSI.COM    (dsinc!elm)

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