a summary of the commands:
`git branch`::
- list all branches
+ list all branches.
`git branch <branch>`::
create a new branch named `<branch>`, referencing the same
- point in history as the current branch
+ point in history as the current branch.
`git branch <branch> <start-point>`::
create a new branch named `<branch>`, referencing
`<start-point>`, which may be specified any way you like,
- including using a branch name or a tag name
+ including using a branch name or a tag name.
`git branch -d <branch>`::
- delete the branch `<branch>`; if the branch you are deleting
- points to a commit which is not reachable from the current
- branch, this command will fail with a warning.
+ delete the branch `<branch>`; if the branch is not fully
+ merged in its upstream branch or contained in the current branch,
+ this command will fail with a warning.
`git branch -D <branch>`::
- even if the branch points to a commit not reachable
- from the current branch, you may know that that commit
- is still reachable from some other branch or tag. In that
- case it is safe to use this command to force Git to delete
- the branch.
+ delete the branch `<branch>` irrespective of its merged status.
`git checkout <branch>`::
make the current branch `<branch>`, updating the working
- directory to reflect the version referenced by `<branch>`
+ directory to reflect the version referenced by `<branch>`.
`git checkout -b <new> <start-point>`::
create a new branch `<new>` referencing `<start-point>`, and
check it out.
Modifying the index is easy:
-To update the index with the new contents of a modified file, use
+To update the index with the contents of a new or modified file, use
-------------------------------------------------
$ git add path/to/file
-------------------------------------------------
-To add the contents of a new file to the index, use
-
--------------------------------------------------
-$ git add path/to/file
--------------------------------------------------
-
-To remove a file from the index and from the working tree,
+To remove a file from the index and from the working tree, use
-------------------------------------------------
$ git rm path/to/file
Merging multiple trees
----------------------
-Git helps you do a three-way merge, which you can expand to n-way by
-repeating the merge procedure arbitrary times until you finally
-"commit" the state. The normal situation is that you'd only do one
-three-way merge (two parents), and commit it, but if you like to, you
-can do multiple parents in one go.
+Git can help you perform a three-way merge, which can in turn be
+used for a many-way merge by repeating the merge procedure several
+times. The usual situation is that you only do one three-way merge
+(reconciling two lines of history) and commit the result, but if
+you like to, you can merge several branches in one go.
-To do a three-way merge, you need the two sets of "commit" objects
-that you want to merge, use those to find the closest common parent (a
-third "commit" object), and then use those commit objects to find the
-state of the directory ("tree" object) at these points.
+To perform a three-way merge, you start with the two commits you
+want to merge, find their closest common parent (a third commit),
+and compare the trees corresponding to these three commits.
-To get the "base" for the merge, you first look up the common parent
-of two commits with
+To get the "base" for the merge, look up the common parent of two
+commits:
-------------------------------------------------
$ git merge-base <commit1> <commit2>
-------------------------------------------------
-which will return you the commit they are both based on. You should
-now look up the "tree" objects of those commits, which you can easily
-do with (for example)
+This prints the name of a commit they are both based on. You should
+now look up the tree objects of those commits, which you can easily
+do with
-------------------------------------------------
$ git cat-file commit <commitname> | head -1