Committing Partial Changes in a Changed File

(credit: https://stackoverflow.com/a/1085191)

$ git add --patch <file>
# you'll be presented with a patch and asked:
# Stage this hunk [y,n,q,a,d,j,J,g,/,e,?]?

The options are:

• y: add this change to staged
• n: do not stage this change
• s: automatically split this change into smaller changes
• q: do not stage this or any remaining changes
• ?: print help

Afterwords:

• git diff --staged <file> will show you the staged changes for the file
• git reset -p will undo the staged changes