问题
Using git add -p, one can select changes to a file for staging.
One can manually change the hunk size (Can I modify git-add's hunk size?), but I would like to know how to change the default hunk size (for example to a single line).
回答1:
You can use the GIT_DIFF_OPTS environment variable to tell Git how many lines of context it should include in a hunk every time it has to generate a patch.
In your case, you would say:
export GIT_DIFF_OPTS=-u0
where the -u0 option (the short version of --unified) puts 0 lines of context in each hunk, which effectively reduces it to only contain the lines that have changed.
Update (2018-11-01)
If you're just interested in changing the default hunk size in the output of git diff, you can set it in your .gitconfig file by using the diff.context setting:
git config --global diff.context 0
Interestingly, you can also configure the number of lines to include between hunks with the diff.interHunkContext setting:
git config --global diff.interHunkContext 0
Setting it to 0 will effectively concatenate the hunks one after the other.
来源：https://stackoverflow.com/questions/33891010/can-i-modify-git-adds-default-hunk-size