[Divingduck]

Hi Kovid,
I just do some translations and I check the diff tool from command line.

The translation string gives an example:
calibre-debug --diff file2 fiel1
Instead of:
calibre-debug --diff -- "file 2.epub" "file 1.epub"

The User Guide for Command Line Interface has sometimes problems with --. There is shown sometimes a – instead of --.

Example for calibre-debug:
In general description and for commands like this (and for some other):
--diff
Run the calibre diff tool. For example: calibre-debug –diff – file1 file2

An additional point: I often recognize that users came in trouble because they don't know how to use an option correctly. Most commonly are missing quotation marks because of a file name with spaces or/and missing file extensions like "book 1" -> "book 1.epub". Path names are also a point. Maybe it is a good idea to put this as an explanation in the first place of chapter Command Line Interface

Finally, I recognize a different behavior at the bottom of the window for the information line (pls. see picture, first part is via command line and below part is via editor).You show the information about which files are part of the comparison if I open the diff tool from the editor. This is missing if I open the tool via command line.