paths(4)                                                    paths(4)


       NAME
             paths - pathrouter routing database

       DESCRIPTION
             The paths file is the routing database for the pathrouter
             command.  Each line of the file provides routing information
             to either a host or to a domain.  Each line should have either
             two or three tab characters (ascii 0x9) as separated fields.
             The format of each line in the paths file is:

                         key  route   [cost]

             The key field is the key  on  which  searches  are  performed.
             Typically, either a UUCP host name or a domain name is used as
             the value for key.  pathrouter uses a binary search  algorithm
             when  searching  the  database,  so the keys must be sorted in
             ascending order.  Case is ignored when searching, so the  keys
             should be converted to lower case before sorting.

             The route field is a printf string that details the route that
             mail should take on the path to key.

             The cost field is not referenced by pathrouter in this release
             and a value for cost is optional.

       EXAMPLES
             Here is a sample paths file for a small host, where complete
             routing information does not need to be maintained.  It
             illustrates many of the characteristics of the paths file.
             Assume that the host's name is mypc, and that it is in domain
             Also, assume that it has a dedicated link to two smart hosts
             named bighub and gateway, and that the administrators for
             bighub and gateway have given mypc permission to use each of
             the smart hosts as a mail relay.  Further, assume that bighub
             is connected to the European network and that gateway is
             connected directly to the USA.  Lastly, assume that mypc has a
             dialed-on-demand link to another computer named friend and
             that through this link another computer named japan can be
             reached.

             Here is a typical paths file based on the example described
             above.:

                          .com gateway!%s  300
                          .edu gateway!%s  300
                          .mypc.mydomain   %s    0


                           Copyright 1994 Novell, Inc.               Page 1

      paths(4)                                                    paths(4)


                         .org gateway!%s  0
                         friend     friend!%s   300
                         japan      friend!japan!%s   300
                         mypc %s    0
                         smart-host bighub!%s   95

            In this example, domain .com, .edu, and  .org  are  routed  to
            gateway  which  has  a  US  connection.  Other domains will be
            routed to the smart-host which is bighub.  Mail  to  the  host
            japan will be routed via friend.

            The following shows example  output  for  pathrouter  for  the
            above paths file.

                        $ pathrouter -p john@usl.com arnold@friend.mypc.domain
                        arnold@friend.mypc.domain arnold
                        john@usl.com gateway!usl.com!john

                        $ pathrouter -d john@uknet.ac.uk
                        resolve: parse address 'john@uknet.ac.uk'
                              = 'john' @ 'uknet.ac.uk' (DOMAIN)
                        getpath: looking for '.uknet.ac.uk'
                        getpath: looking for 'uknet.ac.uk'
                        getpath: looking for '.ac.uk'
                        getpath: looking for 'ac.uk'
                        getpath: looking for '.uk'
                        getpath: looking for 'uk'
                        getpath: looking for 'smart-host'
                        route:  'uknet.ac.uk' (NULL) = 'bighub!%s' (0)
                        resolve: parse route 'bighub!uknet.ac.uk!john'
                              = 'uknet.ac.uk!john' @ 'bighub' (UUCP)
                        resolve 'john@uknet.ac.uk' = 'uknet.ac.uk!john'
                              @ 'bighub' (UUCP)
                        bighub!uknet.ac.uk!john

            $ pathrouter fred@japan help@usl.com
            gateway!usl.com!help friend!japan!fred

      REFERENCES
            pathrouter(1M)








                          Copyright 1994 Novell, Inc.               Page 2