Automatic Comparison Functions
DiffDog provides options that automatically start a comparison when files are loaded or edited. In addition, you can display the comparison options each time before a comparison is actually started. Note that all of these options are toggle commands.
Autostart Comparison
If the Autostart Comparison option is toggled on, then a comparison is automatically made when files or directories are loaded into a comparison window. If this option is toggled off, then a comparison (file or directory) must be explicitly started.
To autostart comparisons:
•Activate the menu option Diff and Merge | Autostart Comparison or activate the corresponding toolbar icon 
in the Diff and Merge toolbar.
Compare while Editing
A toggle to compare or not compare documents in File Comparison windows while editing. If toggled on, differences are highlighted as you edit. If toggled off, highlighting of differences is turned off in both documents as soon as you start typing in either document; to highlight differences after editing, you must run a comparison.
To compare files while editing:
•Activate the menu option Diff and Merge | Compare while Editing or activate the corresponding toolbar icon 
in the Diff and Merge toolbar.
Show Options Before Comparison
This command is toggled either on or off for individual comparison windows. When toggled on for a comparison window, the Comparison Options dialog box is displayed each time a comparison is made in that window. Note that the Comparison Options dialog box is not displayed before comparisons made dynamically by DiffDog while you edit a document.
To show the options before comparison:
•Activate the menu option Diff and Merge | Show Options Before Comparison or activate the corresponding toolbar icon 
in the Diff and Merge toolbar.