git - viewing changes - diff and log
Diff and log between two branches (all changes on both branches)
To see all changes between two branches, use diff with two or three dots and log with three dots between branch names.
Note: the confusing part is that log with two dots only shows changes on one branch, while diff with two dots includes changes on both branches (showing changes from one branch as removed and from another branch - as added).
See the section below on how to see only new changes on the branch.
For example, we have a history like this:
... A ---- B ---- C ---- D master
\
E ---- F branch
List of new commits on both branches (log with three dots):
git log master...branch
commit F
commit D
commit E
commit C
# With --left-right it shows additional markers for commits
git log --left-right master...branch
commit > F
commit < D
commit > E
commit < C
Diff with two dots, master commits shown as removed changes, branch commits - as added:
git diff master..branch
-changes from C,D
+changes from E,F
# Same is without dots
git diff master branch
-changes from C,D
+changes from E,F
Diff with two dots, branch commits are shown as removed changes, master commits as added:
git diff branch..master
+changes from C,D
-changes from E,F
# Same is without dots
git diff branch master
+changes from C,D
-changes from E,F
Diff and log between two branches (only branch changes)
Often, we want to only see changes on the branch, without seeing what has changed on master (or on another base branch).
In this case, we can use git log with two dots to get the list of changes and git log -p to see the diff (while git diff with two dots will still show changes from the base branch, so is not suitable for this task).
For example, we have a history like this:
... A ---- B ---- C ---- D master
\
E ---- F branch
List of new commits on branch (log with two dots):
git log master..branch
F
E
List of new commits on branch (cherry):
git cherry master
+ F
+ E
git cherry -v master
+ F commit message
+ E commit message
The git cherry command provides a more compact output with the list of new commits on the branch comparing to master.
List of new commits on master (log with two dots):
git log branch..master
D
C
Diff, only new commits on branch (log with two dots and -p or diff with three dots):
git log -p master..branch
+changes from F
+changes from E
git diff master...branch
+changes from E
+changes from F
Diff, only new commits on master (log with two dots and -p or diff with tree dots):
git log -p branch..master
+changes from D
+changes from C
git diff branch...master
+changes from C
+changes from D
Git diff and log inconsistency
In the sections above we can see that git diff and git log with three and two dots seem to behave inconsistently:
git log master..branch- only new commits onbranchgit diff master..branch- changes on bothmasterandbranchgit log master...branch- new commits on bothmasterandbranchgit diff master...branch- only changes onbranch
The definition of two and three dots:
- Double Dot - range of commits that are reachable from one commit but aren’t reachable from another (in other words, new commits on branch that are not present on master)
- Triple-dot - all the commits that are reachable by either of two references but not by both of them (changes on both branches, but not common changes before that).
And git log does exactly that - new commits on the branch with two dots and all new commits on both branches with tree dots.
While git diff works differently, here is a summary from the man page:
Comparing branches
$ git diff topic master (1)
$ git diff topic..master (2)
$ git diff topic...master (3)
1. Changes between the tips of the topic and the master branches.
2. Same as above.
3. Changes that occurred on the master branch since when the topic branch was started off it.
This is why I like git log -p to show diffs instead of git diff.
It is more consistent and easier to remember - less dots (two) - less changes (only new changes on the branch), more dots (three) - more changes (changes on both branches):
git log master..branch- only new commits onbranchgit log -p master..branch- only changes onbranchgit log master...branch- new commits on bothmasterandbranchgit log -p master...branch- changes on bothmasterandbranch
Diff staged changes
Show staged changes - added to index, but not commited yet:
git diff --cached
# or
git diff --staged
Diff pulled changes
Show diff of changes pulled from upstream:
git pull origin
git diff @{1}..
Here @ means HEAD and @{1} means “prior value of the HEAD”, the list of prior values can be seen with git reflog.
Log without merge commits
To show the log without merge commits use --no-merges flag:
git log --no-merges
Log without another branch commits
To exclude commits on master (or another) branch, use --not flag:
git log contrib --not master # or git log contrib ^master
To exclude both commits on master commits and merge commits:
git log contrib ^master --no-merges
What was added in remote branch, but not in local:
git log origin/featureA ^featureA
Note: these three commands are equivalent:
git log refA..refB
git log ^refA refB
git log refB --not refA
Show all commits that are reachable from refA or refB but not from the refC:
git log refA refB ^refC
git log refA refB --not refC
Git log formatting
Log with diff (p), only last two entries:
git log -p -2
One line log:
git log --pretty=oneline
Log with graph:
git log --pretty=format:"%h %s" --graph
Format log:
git log --pretty=format:"%h - %an, %ar : %s"
Log formatting options:
%H Commit hash
%h Abbreviated commit hash
%T Tree hash
%t Abbreviated tree hash
%P Parent hashes
%p Abbreviated parent hashes
%an Author name
%ae Author e-mail
%ad Author date (format respects the –date= option)
%ar Author date, relative
%cn Committer name
%ce Committer email
%cd Committer date
%cr Committer date, relative
%s Subject
Links
Stackoverflow: How can I generate a git diff of what’s changed since the last time I pulled?
ProGit: Git Tools - Revision Selectio
ProGit: Viewing Your Staged and Unstaged Changes
