NAME

       setforward - create a forwarding database

SYNOPSIS

       setforward cdb tmp

DESCRIPTION

       setforward  reads a table of forwarding instructions from its standard input.  It converts the table into
       a forwarding database.  The forwarding database can be used by fastforward.

       setforward writes the forwarding database to tmp; it then moves tmp to cdb.  tmp and cdb must be  on  the
       same filesystem.

       If there is a problem creating tmp, setforward complains and leaves cdb alone.

       The forwarding database format is portable across machines.

INSTRUCTION FORMAT

       A forwarding instruction contains a target, a colon, a series of commands, and a semicolon.  Each command
       is a recipient address, owner address, external mailing list, or  program.   Commands  are  separated  by
       commas.

       For example,

          root@yp.to: god@heaven.af.mil, staff@af.mil;

       says  that  mail  for  root@yp.to  should  be  forwarded to the recipient addresses god@heaven.af.mil and
       staff@af.mil.

       When setforward sees # it ignores all text from # to the end of the line:

          # this is a comment

       setforward ignores all other line endings, so you can split a forwarding instruction  across  lines.   It
       also ignores spaces and tabs.  Exception: you can put a space (or tab or comma or whatever) into a target
       or command by putting a backslash in front of it.  (However, NUL bytes are not permitted anywhere.)

TARGETS

       When fastforward sees  the  incoming  address  user@host.dom,  it  tries  three  targets:  user@host.dom,
       @host.dom,  and  user@.   It  obeys  the  commands  for the first target that it finds.  Target names are
       interpreted without regard to case.

       All the commands for a single target must be listed in a single instruction.  Exception: an owner address
       can be listed in a separate instruction.

RECIPIENT ADDRESSES

       If a command begins with an ampersand, setforward takes the remaining bytes in the command as a recipient
       address:

          boss@yp.to: &god@heaven.af.mil;

       fastforward sends each incoming mail message to  the  recipient  address.   The  recipient  address  must
       include a fully qualified domain name.  It cannot be longer than 800 bytes.

       If  a  recipient  address is itself a target in the forwarding table, fastforward will recursively handle
       the instructions for that target.  Note that @host.dom and user@ wildcards do not apply here; they  apply
       only to the incoming address.

       If a command begins with a letter or number, setforward takes the entire command as a recipient address:

          boss@yp.to: god@heaven.af.mil;

OWNER ADDRESSES

       If a command begins with a question mark, setforward takes the remaining bytes in the command as an owner
       address:

          sos@heaven.af.mil: ?owner-sos@heaven.af.mil;

       fastforward uses that address as the envelope sender for forwarded mail, so bounces will go back to  that
       address.   (Normally,  if  a  message  is forwarded to a bad address, it will bounce back to the original
       envelope sender.)

EXTERNAL MAILING LISTS

       If a command begins with a dot or slash, setforward takes the entire command as  the  name  of  a  binary
       mailing list file created by setmaillist:

          sos@heaven.af.mil: /etc/lists/sos.bin;

       fastforward will read and obey the commands in that file.  The file must be world-readable and accessible
       to fastforward.

PROGRAMS

       If a command begins with a vertical bar or exclamation point, setforward takes the rest of the command as
       the name of a program to run:

          dew@: |dew-monitor;

       For  a  vertical bar, fastforward feeds the message to that program.  An exclamation point works the same
       way except that fastforward inserts $UFLINE, $RPLINE, and $DTLINE in front of the message.

DUPLICATES

       When fastforward is building the recipient list for a message, it keeps track of the recipient  addresses
       and external mailing lists it has used.  If the same command shows up again, it skips it.  For example:

          everybody@yp.to: programmers@yp.to, testers@yp.to;
          programmers@yp.to: joe@yp.to, bob@yp.to;
          testers@yp.to: joe@yp.to, fred@yp.to;

       A  message to everybody@yp.to will be sent to joe@yp.to only once.  (This also means that addresses in an
       internal forwarding loop are discarded.)

       Exception: If a target has an owner address, commands for  that  target  are  considered  different  from
       commands for ``outside'' targets.

SEE ALSO

       newaliases(1), preline(1), printforward(1), setmaillist(1)

                                                                                                   setforward(1)