The File Compare (Compare menu)
command identifies
the differences between the active open file and another open file. The
comparison can either be a straight text comparison or the comparison
of specific words by value.
Once this is selected, you must choose the other open text window. When you move the cursor over an appropriate file, the cursor shape changes to a crosshair.
The comparison is then carried out, beginning at the current text cursor position in each window.
When a whole line appears to be different, the comparison function attempts to automatically resynchronise the comparison.
The result of the comparison is stored in a file called output.log, which is displayed in a new window from the beginning of the comparison process.