git - Shorthand for getting the diff from the last N commits? -

i know can do:

git diff head^..head 

but there shorthand that's easier remember, like:

git diff foo n 

where n can number of commits cumulative diff of?

from specifying revisions of git rev-parse man page:

a suffix ~<n> revision parameter means commit object <n>th generation grand-parent of named commit object, following first parent.
i.e. rev~3 equivalent rev^^^ equivalent rev^1^1^1.

consider examples in git diff man page:

git diff head^..head git diff head^.. git diff head^ head 

are equivalent forms (thanks chrisk head^.. form, mentioned in comments).
(they not equivalent git diff head^, mark longair comments, since diff working directory, not last commit)

so:

git diff head~15       # diff working tree 15th previous commit git diff head~15 head  # diff last commit  15th previous commit 

should need (as khmarbaise mentions in comment).