git whatchanged <option>...:
Shows commit logs and diff output each commit introduces.
New users are encouraged to use git-log(1) instead. The whatchanged command is essentially the same as git-log(1) but defaults to show the raw format diff output and to skip merges.
The command is kept primarily for historical reasons; fingers of many people who learned Git long before git log was invented by reading Linux kernel mailing list are trained to type it.
git whatchanged -p v2.6.12.. include/scsi drivers/scsi
git whatchanged --since="2 weeks ago" -- gitk
Part of the git(1) suite