How to stage part of a file in Git

Mixed edits in one file often need to become separate commits, such as a bug fix and a wording cleanup made during the same session. Staging only selected hunks keeps the next commit focused while the rest of the file remains modified in the working tree.

Git keeps the next commit in the index, also called the staging area, separately from the working tree copy on disk. git add –patch compares those two states and asks about each diff hunk, so answering y stages that hunk and answering n leaves it unstaged.

Patch mode works best when the wanted and unwanted edits are separated enough to appear as different hunks. If Git shows both edits in one hunk, split the hunk when offered or edit the patch carefully; otherwise leave the hunk unstaged and separate the source edits before staging.

1. Check that the file has unstaged changes.

   $ git status --short
    M notes.txt

2. Start patch mode for the file.

   $ git add --patch notes.txt
   diff --git a/notes.txt b/notes.txt
   index 7efee23..a4e0668 100644
   --- a/notes.txt
   +++ b/notes.txt
   @@ -1,4 +1,4 @@
   -Release notes
   +Release notes for v2
    
    Install the package.
    Open the app.
   (1/2) Stage this hunk [y,n,q,a,d,k,K,j,J,g,/,e,p,P,?]? y
   @@ -11,4 +11,4 @@ Notify the team.
    Close the ticket.
    Archive the notes.
    
   -Cleanup notes
   +Cleanup notes updated
   (2/2) Stage this hunk [y,n,q,a,d,K,J,g,/,e,p,P,?]? n

   Use y to stage the displayed hunk, n to leave it unstaged, q to quit, s to split a large hunk when Git offers it, and e to edit the patch before applying it to the index.

3. Confirm that the file now has both staged and unstaged edits.

   $ git status --short
   MM notes.txt

   In short status, the first column reports the index and the second column reports the working tree. MM means notes.txt has staged content and remaining unstaged content.

4. Review only the staged hunk.

   $ git diff --cached -- notes.txt
   diff --git a/notes.txt b/notes.txt
   index 7efee23..055dd9d 100644
   --- a/notes.txt
   +++ b/notes.txt
   @@ -1,4 +1,4 @@
   -Release notes
   +Release notes for v2
    
    Install the package.
    Open the app.

5. Review the hunk that remains unstaged.

   $ git diff -- notes.txt
   diff --git a/notes.txt b/notes.txt
   index 055dd9d..a4e0668 100644
   --- a/notes.txt
   +++ b/notes.txt
   @@ -11,4 +11,4 @@ Notify the team.
    Close the ticket.
    Archive the notes.
    
   -Cleanup notes
   +Cleanup notes updated

   The remaining hunk will not be included in the next commit unless it is staged later.