difftool.<tool>.path:: Override the path for the given tool. This is useful in case your tool is not in the PATH. difftool.<tool>.cmd:: Specify the command to invoke the specified diff tool. The specified command is evaluated in shell with the following variables available: 'LOCAL' is set to the name of the temporary file containing the contents of the diff pre-image and 'REMOTE' is set to the name of the temporary file containing the contents of the diff post-image. difftool.prompt:: Prompt before each invocation of the diff tool.