Example page features

This page applies to Harlequin v13.1r0 and later; and to Harlequin MultiRIP but not Harlequin Core.
It is possible to write all the necessary code for pagebuffer redirection as a page feature. This is a simple example, and should be made more robust for production use.
TEXT
            %!
            % Page feature to send pagebuffers to a different directory
            % Notes:
            % The directory is fixed, and here within the SW directory, but
            % you can edit this page feature to use a directory elsewhere.
            % Non-existent directories are created when device is first used.
            % If setting up other redirections, copy this feature then
            % 1. change name and /Prefix directory for the device,
            % 2. create a new device of DeviceType 30 and set the /IODevice to
            % be the name of the device in step (a) and
            % 3. use the new device name as /RasterRedirectRDWR of the
            % pagebuffer% device
            % 1: Set up a target directory and mount a device on it.
            % This is a persistent change within this ScriptWorks session.
            % Use of devstatus detects already mounted device
            % but does not check if /Prefix is the same or different, so
            % any change to this page feature is effective only when
            % ScriptWorks is restarted
            statusdict begin
            (%pgb-redir1%) dup devstatus
            {
              9 { pop } repeat
            }
            {
              dup devmount pop
              <<
                /Password 0
                /DeviceType 0
                /SearchOrder -1
                /Prefix (redir1/)
                /Enable false
              >> setdevparams
            } ifelse end
            % 2: setup a device of DeviceType 30 and make the above device
            % the IODevice. This is a persistent change within this SW
            % session.
            mark (%pgbrdwr1%) devstatus not
            {
              {
                (%pgbrdwr1%) dup devmount pop
              <<
                /Password 0
                /DeviceType 30
                /IODevice (pgb-redir1)
                /SearchOrder -1
                /Enable false
              >> setdevparams
              } stopped
            } if cleartomark
            % 3: Make the target directory the RasterRedirectRDWR for the
            % device
            % set up in step 2. This change holds for this job only.
            (%pagebuffer%)
            <<
            /Password 0
            /RasterRedirectRDWR (pgbrdwr1)
            % /RedirectFileNamedWithJobname false
            >> setdevparams
            % 4. Tell the page device to use the redirection device
            % This change holds for this job only.
            <<
            /OutputRedirect true
            >> setpagedevice
            % 4: Pagebuffer files are named <jobname>-<pagenumber>.PGB
            % Duplicated pages have +1, +2 added
            % For example: <jobname>-<pagenumber>+1.PGB
            % Uncomment RedirectFileNamedWithJobname line in step 3 above
            % to get a name like <jobnumber>-<pagenumber>-<separationnumber>
            % .PGB
            % OR
            % Uncomment next (setuserparams) line to set up a fixed
            % jobname for use in the filename
            % OR
            % Add suitable code if you wish to vary the name, based on
            % resolution or other parameters s appropriate.
            % NOTE: Redirection does not escape any special characters in
            % the pagebuffer name, however created.
            << /Jobname (rdjob) >> setuserparams
            % end of example redirect page feature