Arbortext Editor has a compare_files() function that takes two files as input and 
generates a third file that shows the differences between the two input files. 
The generated file shows the changes by placing the differences in <Insert> and <Delete> XML tags.

You can repeatedly use this function in a file that you call from Arbortext Editor to
quickly create comparison files. This feature can be quite time-saving when going through
edits from your editor and comparing the changes.

To create such a file and call it from Arbortext editor:

1. Place the edited XML files in a directory named edited.

2. Create two directories at the same level as the edited directory.
   Name these directories originals and diffs.

3. Copy the original files into the originals directory.

4. Copy and paste the following perl code into a file that you name tmp.pl:

      #!/usr/bin/perl

      open(F1, "ls |") || die "Could not get list of files: $!\n";
      open(F2, ">SOURCE_THIS_FILE.txt") || die "Could not open output file: $!\n";

      while(<F1>){
          if($_ =~ /(.*).dita/) {
            print F2 "compare_files(\"$1.dita\", \"../edited/$1.dita\", \"../diffs/$1.dita\");\n";
          }
      }

      close(F1);
      close(F2);

5. Place tmp.pl in your originals directory.

6. Run tmp.pl to create a input file for Arbortext editor.

   On UNIX, run the script using this command:
      ./tmp.pl

   On Windows, run the script in a command window:
      perl tmp.pl

   The perl script creates a new file called SOURCE_THIS_FILE.txt.

7. Using Windows Explorer, navigate to the originals directory and
   double-click any .dita file to open the file in Arbortext Editor.

   This step ensures that Arbortext Editor can open the files as listed
   with their relative paths in the SOURCE_THIS_FILE.txt file.

8. Close the .dita file you just opened but leave Arbortext Editor open.

9. Run the SOURCE_THIS_FILE.txt file by entering "source SOURCE_THIS_FILE.txt" 
   in the Arbortext Editor command pane at the bottom of the Arbortext Editor window.

   If the command pane is not visible, select Tools > Preferences, select
   the "Command Line" box, and click OK.

   Arbortext Editor generates the comparison files in the ../diffs directory. These comparison
   files use the names of the original files so that after you approve or reject the changes 
   in the comparison file, you can copy it over the original file in source control without
   renaming it.