diff

View diff between working tree and index (changes will disappear after git add):

git diff

View staged differences (git added) and HEAD:

git diff --cached

View differences between two revisions:

git diff eebb22 06637b

For a single file:

f=
git diff -- "$f"

Ignore whitespace only changes (e.g. indent changes):

git diff -w

Ignore changes when a file is moved to another name:

git diff -M

This can be auto detected even before staging with git mv when files are exactly the same. It is also possible to consider moves up to a percentage of similarity via -M90.

Show only how many lines were added / removed from each file, and the order of addition/removal:

git diff --stat

Sample output:

app/assets/javascripts/extensions/array.js                  |  2 +-
app/assets/javascripts/groups.js.coffee                     |  2 +-
app/assets/javascripts/markup_preview.js.coffee             | 39 +++++++++++++++++++++++++++++++++++++++
app/assets/javascripts/notes.js.coffee                      | 74 +++++---------------------------------------------------------------------
app/assets/javascripts/profile.js.coffee                    |  2 +-
app/assets/stylesheets/g
spec/seed_project.tar.gz                                    | Bin 9833961 -> 9789938 bytes

Show only how many file changed, and how many additions deletions were there:

git diff --shortstat

Sample output:

40 files changed, 244 insertions(+), 203 deletions(-)

View only changed words:

git diff -M

Show only the names of changed files

http://stackoverflow.com/questions/1552340/show-all-changed-files-between-two-git-commits:

git diff-tree --no-commit-id --name-only -r HEAD

Sample output:

file1.md
file2.md

color-words

word-diff

git diff --word-diff

Sample output:

The [-gud-]{+good+} word.

colored if you have --color.

Show only color, very neat:

git diff --word-diff=color

Same as:

git diff --color-words

Sample output:

The gudgood word.

where gud is red and good is green.

diff-highlight is a related contrib script.

Diff format

Sample output:

@@ 3,2 3,3 @@
 before
+error
 after

Meaning:

• before, line 3 was before, line 4 after.

  There were 2 lines total in what we see.

• after, error was added after before, becoming line 4

  There will be 3 lines total in what we see.

  + indicates that a line was added.

  Not surprisingly, if we remove something, a - will show instead

After a git merge, in case of merge conflicts, git diff shows a special mode that shows diffs to both parents:

+     Added in theirs
+     Added in theirs2
 -    Removed in ours
++    Added in both
 +    Added in ours

Newline at the end of file

If the file does not end in a newline, you will see things like:-

Add a without newline at end of file:

+a
\ No newline at end of file

Add \n at end of file that had no ending newline:

-a
\ No newline at end of file
+a

This way, every line that starts with + is assumed to have a newline at the end, unless stated otherwise.

Beware of editors that do magic things with ending newlines: someday it may bite you.

For example, Vim 7.3 hides trailing newlines by default.

tail file | hd and truncate -s -1 will never lie to you.

Side-by-side diff

Not possible natively: you must use git difftool.

With difftool, one option seems to be: https://github.com/ymattw/cdiff