Git add --interactive, or how to make amazing commits

#scm

#add

#staging

#best practices

#git

In git you can, for a commit, add only parts of a file. for that you'll need to use the –interactive option :

git add --interactive

git add -i

once you've typed this command, you'll get :

> git add -i
           staged     unstaged path
  1:    unchanged        +2/-0 README
  2:    unchanged        +4/-0 index.html

*** Commands ***
  1: [s]tatus     2: [u]pdate     3: [r]evert     4: [a]dd untracked
  5: [p]atch      6: [d]iff   7: [q]uit   8: [h]elp
What now>

there, you'll have many options, but two really matter for you : to patch (add parts of the files for the commit) and to quit (to leave the interactive add).

So, let's patch :

What now> p
           staged     unstaged path
  1:    unchanged        +2/-0 [R]EADME
  2:    unchanged        +4/-0 [i]ndex.html
Patch update>>

Now we have to choose the files we need to add :

Patch update>> 2
           staged     unstaged path
  1:    unchanged        +2/-0 [R]EADME
* 2:    unchanged        +4/-0 [i]ndex.html
Patch update>>

All the files with a star (*) at the left of the number will be processed.

To select the files, you have many possibilities:

#: Select the file number #</li>
-#: Unselect the file number #</li>
*: Select all files</li>
#-#: Select an interval of files</li>
#-: Select the files from the # to the last</li>

Of course, all those notations can be mixed, for example, if you have 10 files changed, you can select this :

Patch update>> 1 3-6 8-

Which will select the 1, 3, 4, 5, 6, 8, 9 and 10

When you've selected the files you want, press enter.

if you want to do pick diffs in all the files, you can do:
git add -p

which is the same as doing:

git add --interactive
p (for patch)
* (choose all the files)

From now, you will be asked for each diff of each file if you want to add it, with many possible answers :

diff --git a/index.html b/index.html
index e574d0d..057bf2d 100644
--- a/index.html
+++ b/index.html
@@ -1,6 +1,10 @@
 <html>
     <head>
+        <script type="text/javascript">
+            alert('Hello world');
+        </script>
     </head>
     <body>
+        <h1>title</h1>
     </body>
 </html>
Stage this hunk [y,n,q,a,d,/,s,e,?]?

The more important are :

y : yes</li>
n : no</li>
s : split, if the current diff can be splited in few smaller diffs</li>
e : edit, to edit yourself the diff</li>
q : to quit</li>

When you're done, in a git status, you will see your files, both in added files and in modified files :

> git status
# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#   modified:   index.html
#
# Changes not staged for commit:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#   modified:   README
#   modified:   index.html
#

And if it's ok for you, you can commit what you've added.