collection of interrelated snapshots (versions) of the project's
contents.
- A single git repository may contain multiple branches. Each branch
- is a bookmark referencing a particular point in the project history.
- The gitlink:git-branch[1] command shows you the list of branches:
+ A single git repository may contain multiple branches. It keeps track
+ of them by keeping a list of <<def_head,heads>> which reference the
+ latest version on each branch; the gitlink:git-branch[1] command shows
+ you the list of branch heads:
------------------------------------------------
$ git branch
* master
------------------------------------------------
- A freshly cloned repository contains a single branch, named "master",
- and the working directory contains the version of the project
- referred to by the master branch.
+ A freshly cloned repository contains a single branch head, named
+ "master", and working directory is initialized to the state of
+ the project referred to by "master".
- Most projects also use tags. Tags, like branches, are references
- into the project's history, and can be listed using the
+ Most projects also use <<def_tag,tags>>. Tags, like heads, are
+ references into the project's history, and can be listed using the
gitlink:git-tag[1] command:
------------------------------------------------
------------------------------------------------
Tags are expected to always point at the same version of a project,
- while branches are expected to advance as development progresses.
+ while heads are expected to advance as development progresses.
- Create a new branch pointing to one of these versions and check it
+ Create a new branch head pointing to one of these versions and check it
out using gitlink:git-checkout[1]:
------------------------------------------------
$ git reset --hard v2.6.17
------------------------------------------------
- Note that if the current branch was your only reference to a
+ Note that if the current branch head was your only reference to a
particular point in history, then resetting that branch may leave you
- with no way to find the history it used to point to; so use this
- command carefully.
+ with no way to find the history it used to point to; so use this command
+ carefully.
Understanding History: Commits
------------------------------
Understanding history: What is a branch?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- Though we've been using the word "branch" to mean a kind of reference
- to a particular commit, the word branch is also commonly used to
- refer to the line of commits leading up to that point. In the
- example above, git may think of the branch named "A" as just a
- pointer to one particular commit, but we may refer informally to the
- line of three commits leading up to that point as all being part of
+ When we need to be precise, we will use the word "branch" to mean a line
+ of development, and "branch head" (or just "head") to mean a reference
+ to the most recent commit on a branch. In the example above, the branch
+ head named "A" is a pointer to one particular commit, but we refer to
+ the line of three commits leading up to that point as all being part of
"branch A".
- If we need to make it clear that we're just talking about the most
- recent commit on the branch, we may refer to that commit as the
- "head" of the branch.
+ However, when no confusion will result, we often just use the term
+ "branch" both for branches and for branch heads.
Manipulating branches
---------------------
then you can just pull changes from each other's repositories
directly; note that all of the commands (gitlink:git-clone[1],
git-fetch[1], git-pull[1], etc.) that accept a URL as an argument
- will also accept a local file patch; so, for example, you can
+ will also accept a local directory name; so, for example, you can
use
-------------------------------------------------
$ git-merge-index git-merge-one-file hello.c
-------------------------------------------------
-and that is what higher level `git resolve` is implemented with.
+and that is what higher level `git merge -s resolve` is implemented with.
How git stores objects efficiently: pack files
----------------------------------------------
contrast, running "git prune" while somebody is actively changing the
repository is a *BAD* idea).
- Glossary of git terms
- =====================
-
include::glossary.txt[]
Notes and todo list for this manual