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            Subtract Two Window Panes in DirectoryOpus 4.x

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>> About
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This script can be added to DirectoryOpus 4 either as a button or a hotkey
and will deselect all the selected items that can be found in the current
window pane that can also be found amongst the items selected in the other
window pane.

Although simple enough, DirectoryOpus 4 only has the ability to "Select"
and "Toggle" contents but none of those functions work relatively to the
other window pane.

This lets you perform some neat operations: for example, when updating
files, it may happen that you want to copy over the files that exist in one
window pane but not in the other window pane - as in add files that do not
exist in order to not overwrite existing files. You can select the new files
by hand or let this script do it for you.

The script is pure ARexx and Dopus - it would have been much faster if it
had a shell-command that could perform some of the operations that it's
doing but the idea was to create a pure ARexx script with no external
dependencies. This included implementing a lot of auxiliary functions.

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>> How to install
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  1.) Extract the archive
  2.) Place DOpus4-Subtract.rexx wherever you see fit. (It is tidy, for
      example, to create an ARexx directory in DOPUS4: and then place your
      scripts there.)
  3.) Open DirectoryOpus4 and right-click and go to  Project->Configure
  4.) On the screen that pops-up, go to Buttons and create a new button
      somewhere where you see fit.
      4a.) Give the button a name ("Subtract", for example) and create a
           new entry.
      4b.) Set the cycler to ARexx and click the magnifying glass to enter
           the path to the DOpus4-Subtract.rexx script.
  5.) You do not need to set any flags.
  6.) Save and exit and you are done.


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>> How to use
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In DirectoryOpus 4, open up two directories in the two window panes, select
some files in one window, select some files in the other window and hit the
"Subtract" button that you just created. All operations will be mentioned
in the DirectoryOpus 4 top text.

When the subtract process is done you should have only the files selected
that are not amongst the selected files in the other window pane.

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>> Caveats
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  * If your files contain either the asterisk (*) character or the
forward-slash character (/), which are reserved AmigaDOS characters, the
script will fail.

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>> Project Website
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http://grimore.org/amiga/directoryopus/4/subtract

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>> Feedback
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You can reach us at:

   Wizardry and Steamworks
   e-mail: officegrimore.org

PERMISSION  UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP     NAME
---------- ----------- ------- ------- ------ ---------- ------------ ----------
[unknown]                  598    1233  48.5% -lh5- 6553 Jul  5 00:25 DOpus4-Subtract10.info
[unknown]                 1319    3218  41.0% -lh5- fe9c Jul  5 00:23 DOpus4-Subtract10/DOpus4-Subtract.readme
[unknown]                  455     886  51.4% -lh5- c149 Jul  5 00:25 DOpus4-Subtract10/DOpus4-Subtract.readme.info
[unknown]                 1655    5949  27.8% -lh5- f1d0 Jul  4 23:58 DOpus4-Subtract10/DOpus4-Subtract.rexx
[unknown]                  587     859  68.3% -lh5- 00e5 Jul  5 00:25 DOpus4-Subtract10/DOpus4-Subtract.rexx.info
---------- ----------- ------- ------- ------ ---------- ------------ ----------
 Total         5 files    4614   12145  38.0%            Jul  4 20:00