You can use git add --patch <filename> (or -p for short), and git will begin to break down your file into what it thinks are sensible "hunks" (portions of the file). It will then prompt you with this question:
Stage this hunk [y,n,q,a,d,/,j,J,g,s,e,?]?
Here is a description of each option:
- y stage this hunk for the next commit
- n do not stage this hunk for the next commit
- q quit; do not stage this hunk or any of the remaining hunks
- a stage this hunk and all later hunks in the file
- d do not stage this hunk or any of the later hunks in the file
- g select a hunk to go to
- / search for a hunk matching the given regex
- j leave this hunk undecided, see next undecided hunk
- J leave this hunk undecided, see next hunk
- k leave this hunk undecided, see previous undecided hunk
- K leave this hunk undecided, see previous hunk
- s split the current hunk into smaller hunks
- e manually edit the current hunk
- ? print hunk help
If the file is not in the repository yet, you can first do git add -N <filename>. Afterwards you can go on with git add -p <filename>.
Afterwards, you can use:
- git diff --staged to check that you staged the correct changes
- git reset -p to unstage mistakenly added hunks
- git commit -v to view your commit while you edit the commit message.
Note this is far different than the git format-patch command, whose purpose is to parse commit data into a .patch files.
