Git is a fast distributed revision control system.
-This manual is designed to be readable by someone with basic unix
+This manual is designed to be readable by someone with basic UNIX
command-line skills, but no previous knowledge of git.
<<repositories-and-branches>> and <<exploring-git-history>> explain how
It will be useful to have a git repository to experiment with as you
read this manual.
-The best way to get one is by using the gitlink:git-clone[1] command
-to download a copy of an existing repository for a project that you
-are interested in. If you don't already have a project in mind, here
-are some interesting examples:
+The best way to get one is by using the gitlink:git-clone[1] command to
+download a copy of an existing repository. If you don't already have a
+project in mind, here are some interesting examples:
------------------------------------------------
# git itself (approx. 10MB download):
together with a special top-level directory named ".git", which
contains all the information about the history of the project.
-In most of the following, examples will be taken from one of the two
-repositories above.
-
[[how-to-check-out]]
How to check out a different version of a project
-------------------------------------------------
-Git is best thought of as a tool for storing the history of a
-collection of files. It stores the history as a compressed
-collection of interrelated snapshots (versions) of the project's
-contents.
+Git is best thought of as a tool for storing the history of a collection
+of files. It stores the history as a compressed collection of
+interrelated snapshots of the project's contents. In git each such
+version is called a <<def_commit,commit>>.
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
+latest commit on each branch; the gitlink:git-branch[1] command shows
you the list of branch heads:
------------------------------------------------
------------------------------------------------
$ git show
-commit 2b5f6dcce5bf94b9b119e9ed8d537098ec61c3d2
-Author: Jamal Hadi Salim <hadi@cyberus.ca>
-Date: Sat Dec 2 22:22:25 2006 -0800
-
- [XFRM]: Fix aevent structuring to be more complete.
-
- aevents can not uniquely identify an SA. We break the ABI with this
- patch, but consensus is that since it is not yet utilized by any
- (known) application then it is fine (better do it now than later).
-
- Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
- Signed-off-by: David S. Miller <davem@davemloft.net>
-
-diff --git a/Documentation/networking/xfrm_sync.txt b/Documentation/networking/xfrm_sync.txt
-index 8be626f..d7aac9d 100644
---- a/Documentation/networking/xfrm_sync.txt
-+++ b/Documentation/networking/xfrm_sync.txt
-@@ -47,10 +47,13 @@ aevent_id structure looks like:
-
- struct xfrm_aevent_id {
- struct xfrm_usersa_id sa_id;
-+ xfrm_address_t saddr;
- __u32 flags;
-+ __u32 reqid;
- };
-...
+commit 17cf781661e6d38f737f15f53ab552f1e95960d7
+Author: Linus Torvalds <torvalds@ppc970.osdl.org.(none)>
+Date: Tue Apr 19 14:11:06 2005 -0700
+
+ Remove duplicate getenv(DB_ENVIRONMENT) call
+
+ Noted by Tony Luck.
+
+diff --git a/init-db.c b/init-db.c
+index 65898fa..b002dc6 100644
+--- a/init-db.c
++++ b/init-db.c
+@@ -7,7 +7,7 @@
+
+ int main(int argc, char **argv)
+ {
+- char *sha1_dir = getenv(DB_ENVIRONMENT), *path;
++ char *sha1_dir, *path;
+ int len, i;
+
+ if (mkdir(".git", 0755) < 0) {
------------------------------------------------
As you can see, a commit shows who made the latest change, what they
In the following, we say that commit X is "reachable" from commit Y
if commit X is an ancestor of commit Y. Equivalently, you could say
-that Y is a descendent of X, or that there is a chain of parents
+that Y is a descendant of X, or that there is a chain of parents
leading from commit Y to commit X.
[[history-diagrams]]
[[Finding-comments-with-given-content]]
Finding commits referencing a file with given content
------------------------------------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Somebody hands you a copy of a file, and asks which commits modified a
file such that it contained the given content either before or after the
commit. You can find out with this:
-------------------------------------------------
-$ git log --raw -r --abbrev=40 --pretty=oneline -- filename |
+$ git log --raw --abbrev=40 --pretty=oneline -- filename |
grep -B 1 `git hash-object filename`
-------------------------------------------------
$ git status # a brief per-file summary of the above.
-------------------------------------------------
+You can also use gitlink:git-gui[1] to create commits, view changes in
+the index and the working tree files, and individually select diff hunks
+for inclusion in the index (by right-clicking on the diff hunk and
+choosing "Stage Hunk For Commit").
+
[[creating-good-commit-messages]]
Creating good commit messages
-----------------------------
is just a matter of 'not' calling "`git add`" on them. But it quickly becomes
annoying to have these untracked files lying around; e.g. they make
"`git add .`" and "`git commit -a`" practically useless, and they keep
-showing up in the output of "`git status`", etc.
+showing up in the output of "`git status`".
-Git therefore provides "exclude patterns" for telling git which files to
-actively ignore. Exclude patterns are thoroughly explained in the
-gitlink:gitignore[5] manual page, but the heart of the concept is simply
-a list of files which git should ignore. Entries in the list may contain
-globs to specify multiple files, or may be prefixed by "`!`" to
-explicitly include (un-ignore) a previously excluded (ignored) file
-(i.e. later exclude patterns override earlier ones). The following
-example should illustrate such patterns:
+You can tell git to ignore certain files by creating a file called .gitignore
+in the top level of your working directory, with contents such as:
-------------------------------------------------
# Lines starting with '#' are considered comments.
-# Ignore foo.txt.
+# Ignore any file named foo.txt.
foo.txt
# Ignore (generated) html files,
*.html
*.[oa]
-------------------------------------------------
-The next question is where to put these exclude patterns so that git can
-find them. Git looks for exclude patterns in the following files:
-
-`.gitignore` files in your working tree:::
- You may store multiple `.gitignore` files at various locations in your
- working tree. Each `.gitignore` file is applied to the directory where
- it's located, including its subdirectories. Furthermore, the
- `.gitignore` files can be tracked like any other files in your working
- tree; just do a "`git add .gitignore`" and commit. `.gitignore` is
- therefore the right place to put exclude patterns that are meant to
- be shared between all project participants, such as build output files
- (e.g. `\*.o`), etc.
-`.git/info/exclude` in your repo:::
- Exclude patterns in this file are applied to the working tree as a
- whole. Since the file is not located in your working tree, it does
- not follow push/pull/clone like `.gitignore` can do. This is therefore
- the place to put exclude patterns that are local to your copy of the
- repo (i.e. 'not' shared between project participants), such as
- temporary backup files made by your editor (e.g. `\*~`), etc.
-The file specified by the `core.excludesfile` config directive:::
- By setting the `core.excludesfile` config directive you can tell git
- where to find more exclude patterns (see gitlink:git-config[1] for
- more information on configuration options). This config directive
- can be set in the per-repo `.git/config` file, in which case the
- exclude patterns will apply to that repo only. Alternatively, you
- can set the directive in the global `~/.gitconfig` file to apply
- the exclude pattern to all your git repos. As with the above
- `.git/info/exclude` (and, indeed, with git config directives in
- general), this directive does not follow push/pull/clone, but remain
- local to your repo(s).
-
-[NOTE]
-In addition to the above alternatives, there are git commands that can take
-exclude patterns directly on the command line. See gitlink:git-ls-files[1]
-for an example of this.
+See gitlink:gitignore[5] for a detailed explanation of the syntax. You can
+also place .gitignore files in other directories in your working tree, and they
+will apply to those directories and their subdirectories. The `.gitignore`
+files can be added to your repository like any other files (just run `git add
+.gitignore` and `git commit`, as usual), which is convenient when the exclude
+patterns (such as patterns matching build output files) would also make sense
+for other users who clone your repository.
+
+If you wish the exclude patterns to affect only certain repositories
+(instead of every repository for a given project), you may instead put
+them in a file in your repository named .git/info/exclude, or in any file
+specified by the `core.excludesfile` configuration variable. Some git
+commands can also take exclude patterns directly on the command line.
+See gitlink:gitignore[5] for the details.
[[how-to-merge]]
How to merge
Public git repositories
-----------------------
-Another way to submit changes to a project is to tell the maintainer of
-that project to pull the changes from your repository using git-pull[1].
-In the section "<<getting-updates-with-git-pull, Getting updates with
-git pull>>" we described this as a way to get updates from the "main"
-repository, but it works just as well in the other direction.
+Another way to submit changes to a project is to tell the maintainer
+of that project to pull the changes from your repository using
+gitlink:git-pull[1]. In the section "<<getting-updates-with-git-pull,
+Getting updates with git pull>>" we described this as a way to get
+updates from the "main" repository, but it works just as well in the
+other direction.
If you and the maintainer both have accounts on the same machine, then
you can just pull changes from each other's repositories directly;
link:hooks.html[Hooks used by git].)
Advertise the url of proj.git. Anybody else should then be able to
-clone or pull from that url, for example with a commandline like:
+clone or pull from that url, for example with a command line like:
-------------------------------------------------
$ git clone http://yourserver.com/~you/proj.git
Linus's tree will be stored in the remote branch named origin/master,
and can be updated using gitlink:git-fetch[1]; you can track other
public trees using gitlink:git-remote[1] to set up a "remote" and
-git-fetch[1] to keep them up-to-date; see <<repositories-and-branches>>.
+gitlink:git-fetch[1] to keep them up-to-date; see
+<<repositories-and-branches>>.
Now create the branches in which you are going to work; these start out
at the current tip of origin/master branch, and should be set up (using
And browse through the list of patches in the mywork branch using gitk,
applying them (possibly in a different order) to mywork-new using
-cherry-pick, and possibly modifying them as you go using commit
---amend.
+cherry-pick, and possibly modifying them as you go using commit --amend.
+The gitlink:git-gui[1] command may also help as it allows you to
+individually select diff hunks for inclusion in the index (by
+right-clicking on the diff hunk and choosing "Stage Hunk for Commit").
Another technique is to use git-format-patch to create a series of
patches, then reset the state to before the patches:
Other tools
-----------
-There are numerous other tools, such as stgit, which exist for the
+There are numerous other tools, such as StGIT, which exist for the
purpose of maintaining a patch series. These are outside of the scope of
this manual.
The basic requirements:
- It must be readable in order, from beginning to end, by
- someone intelligent with a basic grasp of the unix
- commandline, but without any special knowledge of git. If
+ someone intelligent with a basic grasp of the UNIX
+ command line, but without any special knowledge of git. If
necessary, any other prerequisites should be specifically
mentioned as they arise.
- Whenever possible, section headings should clearly describe