Documentation/diff-config.txt

diff.autorefreshindex::
	When using 'git diff' to compare with work tree
	files, do not consider stat-only change as changed.
	Instead, silently run `git update-index --refresh` to
	update the cached stat information for paths whose
	contents in the work tree match the contents in the
	index.  This option defaults to true.  Note that this
	affects only 'git diff' Porcelain, and not lower level
	'diff' commands such as 'git diff-files'.

diff.external::
	If this config variable is set, diff generation is not
	performed using the internal diff machinery, but using the
	given command.  Can be overridden with the `GIT_EXTERNAL_DIFF'
	environment variable.  The command is called with parameters
	as described under "git Diffs" in linkgit:git[1].  Note: if
	you want to use an external diff program only on a subset of
	your files, you	might want to use linkgit:gitattributes[5] instead.

diff.ignoreSubmodules::
	Sets the default value of --ignore-submodules. Note that this
	affects only 'git diff' Porcelain, and not lower level 'diff'
	commands such as 'git diff-files'. 'git checkout' also honors
	this setting when reporting uncommitted changes.

diff.mnemonicprefix::
	If set, 'git diff' uses a prefix pair that is different from the
	standard "a/" and "b/" depending on what is being compared.  When
	this configuration is in effect, reverse diff output also swaps
	the order of the prefixes:
`git diff`;;
	compares the (i)ndex and the (w)ork tree;
`git diff HEAD`;;
	 compares a (c)ommit and the (w)ork tree;
`git diff --cached`;;
	compares a (c)ommit and the (i)ndex;
`git diff HEAD:file1 file2`;;
	compares an (o)bject and a (w)ork tree entity;
`git diff --no-index a b`;;
	compares two non-git things (1) and (2).

diff.noprefix::
	If set, 'git diff' does not show any source or destination prefix.

diff.renameLimit::
	The number of files to consider when performing the copy/rename
	detection; equivalent to the 'git diff' option '-l'.

diff.renames::
	Tells git to detect renames.  If set to any boolean value, it
	will enable basic rename detection.  If set to "copies" or
	"copy", it will detect copies, as well.

diff.suppressBlankEmpty::
	A boolean to inhibit the standard behavior of printing a space
	before each empty output line. Defaults to false.

diff.<driver>.command::
	The custom diff driver command.  See linkgit:gitattributes[5]
	for details.

diff.<driver>.xfuncname::
	The regular expression that the diff driver should use to
	recognize the hunk header.  A built-in pattern may also be used.
	See linkgit:gitattributes[5] for details.

diff.<driver>.binary::
	Set this option to true to make the diff driver treat files as
	binary.  See linkgit:gitattributes[5] for details.

diff.<driver>.textconv::
	The command that the diff driver should call to generate the
	text-converted version of a file.  The result of the
	conversion is used to generate a human-readable diff.  See
	linkgit:gitattributes[5] for details.

diff.<driver>.wordregex::
	The regular expression that the diff driver should use to
	split words in a line.  See linkgit:gitattributes[5] for
	details.

diff.<driver>.cachetextconv::
	Set this option to true to make the diff driver cache the text
	conversion outputs.  See linkgit:gitattributes[5] for details.

diff.tool::
	The diff tool to be used by linkgit:git-difftool[1].  This
	option overrides `merge.tool`, and has the same valid built-in
	values as `merge.tool` minus "tortoisemerge" and plus
	"kompare".  Any other value is treated as a custom diff tool,
	and there must be a corresponding `difftool.<tool>.cmd`
	option.