--- /dev/null
- This will again prompt your for a message describing the change, and then
+gittutorial(7)
+==============
+
+NAME
+----
+gittutorial - A tutorial introduction to git (for version 1.5.1 or newer)
+
+SYNOPSIS
+--------
+git *
+
+DESCRIPTION
+-----------
+
+This tutorial explains how to import a new project into git, make
+changes to it, and share changes with other developers.
+
+If you are instead primarily interested in using git to fetch a project,
+for example, to test the latest version, you may prefer to start with
+the first two chapters of link:user-manual.html[The Git User's Manual].
+
+First, note that you can get documentation for a command such as "git
+diff" with:
+
+------------------------------------------------
+$ man git-diff
+------------------------------------------------
+
+It is a good idea to introduce yourself to git with your name and
+public email address before doing any operation. The easiest
+way to do so is:
+
+------------------------------------------------
+$ git config --global user.name "Your Name Comes Here"
+$ git config --global user.email you@yourdomain.example.com
+------------------------------------------------
+
+
+Importing a new project
+-----------------------
+
+Assume you have a tarball project.tar.gz with your initial work. You
+can place it under git revision control as follows.
+
+------------------------------------------------
+$ tar xzf project.tar.gz
+$ cd project
+$ git init
+------------------------------------------------
+
+Git will reply
+
+------------------------------------------------
+Initialized empty Git repository in .git/
+------------------------------------------------
+
+You've now initialized the working directory--you may notice a new
+directory created, named ".git".
+
+Next, tell git to take a snapshot of the contents of all files under the
+current directory (note the '.'), with linkgit:git-add[1]:
+
+------------------------------------------------
+$ git add .
+------------------------------------------------
+
+This snapshot is now stored in a temporary staging area which git calls
+the "index". You can permanently store the contents of the index in the
+repository with linkgit:git-commit[1]:
+
+------------------------------------------------
+$ git commit
+------------------------------------------------
+
+This will prompt you for a commit message. You've now stored the first
+version of your project in git.
+
+Making changes
+--------------
+
+Modify some files, then add their updated contents to the index:
+
+------------------------------------------------
+$ git add file1 file2 file3
+------------------------------------------------
+
+You are now ready to commit. You can see what is about to be committed
+using linkgit:git-diff[1] with the --cached option:
+
+------------------------------------------------
+$ git diff --cached
+------------------------------------------------
+
+(Without --cached, linkgit:git-diff[1] will show you any changes that
+you've made but not yet added to the index.) You can also get a brief
+summary of the situation with linkgit:git-status[1]:
+
+------------------------------------------------
+$ git status
+# On branch master
+# Changes to be committed:
+# (use "git reset HEAD <file>..." to unstage)
+#
+# modified: file1
+# modified: file2
+# modified: file3
+#
+------------------------------------------------
+
+If you need to make any further adjustments, do so now, and then add any
+newly modified content to the index. Finally, commit your changes with:
+
+------------------------------------------------
+$ git commit
+------------------------------------------------
+
++This will again prompt you for a message describing the change, and then
+record a new version of the project.
+
+Alternatively, instead of running `git add` beforehand, you can use
+
+------------------------------------------------
+$ git commit -a
+------------------------------------------------
+
+which will automatically notice any modified (but not new) files, add
+them to the index, and commit, all in one step.
+
+A note on commit messages: Though not required, it's a good idea to
+begin the commit message with a single short (less than 50 character)
+line summarizing the change, followed by a blank line and then a more
+thorough description. Tools that turn commits into email, for
+example, use the first line on the Subject: line and the rest of the
+commit in the body.
+
+Git tracks content not files
+----------------------------
+
+Many revision control systems provide an "add" command that tells the
+system to start tracking changes to a new file. Git's "add" command
+does something simpler and more powerful: `git add` is used both for new
+and newly modified files, and in both cases it takes a snapshot of the
+given files and stages that content in the index, ready for inclusion in
+the next commit.
+
+Viewing project history
+-----------------------
+
+At any point you can view the history of your changes using
+
+------------------------------------------------
+$ git log
+------------------------------------------------
+
+If you also want to see complete diffs at each step, use
+
+------------------------------------------------
+$ git log -p
+------------------------------------------------
+
+Often the overview of the change is useful to get a feel of
+each step
+
+------------------------------------------------
+$ git log --stat --summary
+------------------------------------------------
+
+Managing branches
+-----------------
+
+A single git repository can maintain multiple branches of
+development. To create a new branch named "experimental", use
+
+------------------------------------------------
+$ git branch experimental
+------------------------------------------------
+
+If you now run
+
+------------------------------------------------
+$ git branch
+------------------------------------------------
+
+you'll get a list of all existing branches:
+
+------------------------------------------------
+ experimental
+* master
+------------------------------------------------
+
+The "experimental" branch is the one you just created, and the
+"master" branch is a default branch that was created for you
+automatically. The asterisk marks the branch you are currently on;
+type
+
+------------------------------------------------
+$ git checkout experimental
+------------------------------------------------
+
+to switch to the experimental branch. Now edit a file, commit the
+change, and switch back to the master branch:
+
+------------------------------------------------
+(edit file)
+$ git commit -a
+$ git checkout master
+------------------------------------------------
+
+Check that the change you made is no longer visible, since it was
+made on the experimental branch and you're back on the master branch.
+
+You can make a different change on the master branch:
+
+------------------------------------------------
+(edit file)
+$ git commit -a
+------------------------------------------------
+
+at this point the two branches have diverged, with different changes
+made in each. To merge the changes made in experimental into master, run
+
+------------------------------------------------
+$ git merge experimental
+------------------------------------------------
+
+If the changes don't conflict, you're done. If there are conflicts,
+markers will be left in the problematic files showing the conflict;
+
+------------------------------------------------
+$ git diff
+------------------------------------------------
+
+will show this. Once you've edited the files to resolve the
+conflicts,
+
+------------------------------------------------
+$ git commit -a
+------------------------------------------------
+
+will commit the result of the merge. Finally,
+
+------------------------------------------------
+$ gitk
+------------------------------------------------
+
+will show a nice graphical representation of the resulting history.
+
+At this point you could delete the experimental branch with
+
+------------------------------------------------
+$ git branch -d experimental
+------------------------------------------------
+
+This command ensures that the changes in the experimental branch are
+already in the current branch.
+
+If you develop on a branch crazy-idea, then regret it, you can always
+delete the branch with
+
+-------------------------------------
+$ git branch -D crazy-idea
+-------------------------------------
+
+Branches are cheap and easy, so this is a good way to try something
+out.
+
+Using git for collaboration
+---------------------------
+
+Suppose that Alice has started a new project with a git repository in
+/home/alice/project, and that Bob, who has a home directory on the
+same machine, wants to contribute.
+
+Bob begins with:
+
+------------------------------------------------
+$ git clone /home/alice/project myrepo
+------------------------------------------------
+
+This creates a new directory "myrepo" containing a clone of Alice's
+repository. The clone is on an equal footing with the original
+project, possessing its own copy of the original project's history.
+
+Bob then makes some changes and commits them:
+
+------------------------------------------------
+(edit files)
+$ git commit -a
+(repeat as necessary)
+------------------------------------------------
+
+When he's ready, he tells Alice to pull changes from the repository
+at /home/bob/myrepo. She does this with:
+
+------------------------------------------------
+$ cd /home/alice/project
+$ git pull /home/bob/myrepo master
+------------------------------------------------
+
+This merges the changes from Bob's "master" branch into Alice's
+current branch. If Alice has made her own changes in the meantime,
+then she may need to manually fix any conflicts. (Note that the
+"master" argument in the above command is actually unnecessary, as it
+is the default.)
+
+The "pull" command thus performs two operations: it fetches changes
+from a remote branch, then merges them into the current branch.
+
+When you are working in a small closely knit group, it is not
+unusual to interact with the same repository over and over
+again. By defining 'remote' repository shorthand, you can make
+it easier:
+
+------------------------------------------------
+$ git remote add bob /home/bob/myrepo
+------------------------------------------------
+
+With this, Alice can perform the first operation alone using the
+"git fetch" command without merging them with her own branch,
+using:
+
+-------------------------------------
+$ git fetch bob
+-------------------------------------
+
+Unlike the longhand form, when Alice fetches from Bob using a
+remote repository shorthand set up with `git remote`, what was
+fetched is stored in a remote tracking branch, in this case
+`bob/master`. So after this:
+
+-------------------------------------
+$ git log -p master..bob/master
+-------------------------------------
+
+shows a list of all the changes that Bob made since he branched from
+Alice's master branch.
+
+After examining those changes, Alice
+could merge the changes into her master branch:
+
+-------------------------------------
+$ git merge bob/master
+-------------------------------------
+
+This `merge` can also be done by 'pulling from her own remote
+tracking branch', like this:
+
+-------------------------------------
+$ git pull . remotes/bob/master
+-------------------------------------
+
+Note that git pull always merges into the current branch,
+regardless of what else is given on the command line.
+
+Later, Bob can update his repo with Alice's latest changes using
+
+-------------------------------------
+$ git pull
+-------------------------------------
+
+Note that he doesn't need to give the path to Alice's repository;
+when Bob cloned Alice's repository, git stored the location of her
+repository in the repository configuration, and that location is
+used for pulls:
+
+-------------------------------------
+$ git config --get remote.origin.url
+/home/alice/project
+-------------------------------------
+
+(The complete configuration created by git-clone is visible using
+"git config -l", and the linkgit:git-config[1] man page
+explains the meaning of each option.)
+
+Git also keeps a pristine copy of Alice's master branch under the
+name "origin/master":
+
+-------------------------------------
+$ git branch -r
+ origin/master
+-------------------------------------
+
+If Bob later decides to work from a different host, he can still
+perform clones and pulls using the ssh protocol:
+
+-------------------------------------
+$ git clone alice.org:/home/alice/project myrepo
+-------------------------------------
+
+Alternatively, git has a native protocol, or can use rsync or http;
+see linkgit:git-pull[1] for details.
+
+Git can also be used in a CVS-like mode, with a central repository
+that various users push changes to; see linkgit:git-push[1] and
+linkgit:gitcvs-migration[7][git for CVS users].
+
+Exploring history
+-----------------
+
+Git history is represented as a series of interrelated commits. We
+have already seen that the git log command can list those commits.
+Note that first line of each git log entry also gives a name for the
+commit:
+
+-------------------------------------
+$ git log
+commit c82a22c39cbc32576f64f5c6b3f24b99ea8149c7
+Author: Junio C Hamano <junkio@cox.net>
+Date: Tue May 16 17:18:22 2006 -0700
+
+ merge-base: Clarify the comments on post processing.
+-------------------------------------
+
+We can give this name to git show to see the details about this
+commit.
+
+-------------------------------------
+$ git show c82a22c39cbc32576f64f5c6b3f24b99ea8149c7
+-------------------------------------
+
+But there are other ways to refer to commits. You can use any initial
+part of the name that is long enough to uniquely identify the commit:
+
+-------------------------------------
+$ git show c82a22c39c # the first few characters of the name are
+ # usually enough
+$ git show HEAD # the tip of the current branch
+$ git show experimental # the tip of the "experimental" branch
+-------------------------------------
+
+Every commit usually has one "parent" commit
+which points to the previous state of the project:
+
+-------------------------------------
+$ git show HEAD^ # to see the parent of HEAD
+$ git show HEAD^^ # to see the grandparent of HEAD
+$ git show HEAD~4 # to see the great-great grandparent of HEAD
+-------------------------------------
+
+Note that merge commits may have more than one parent:
+
+-------------------------------------
+$ git show HEAD^1 # show the first parent of HEAD (same as HEAD^)
+$ git show HEAD^2 # show the second parent of HEAD
+-------------------------------------
+
+You can also give commits names of your own; after running
+
+-------------------------------------
+$ git-tag v2.5 1b2e1d63ff
+-------------------------------------
+
+you can refer to 1b2e1d63ff by the name "v2.5". If you intend to
+share this name with other people (for example, to identify a release
+version), you should create a "tag" object, and perhaps sign it; see
+linkgit:git-tag[1] for details.
+
+Any git command that needs to know a commit can take any of these
+names. For example:
+
+-------------------------------------
+$ git diff v2.5 HEAD # compare the current HEAD to v2.5
+$ git branch stable v2.5 # start a new branch named "stable" based
+ # at v2.5
+$ git reset --hard HEAD^ # reset your current branch and working
+ # directory to its state at HEAD^
+-------------------------------------
+
+Be careful with that last command: in addition to losing any changes
+in the working directory, it will also remove all later commits from
+this branch. If this branch is the only branch containing those
+commits, they will be lost. Also, don't use "git reset" on a
+publicly-visible branch that other developers pull from, as it will
+force needless merges on other developers to clean up the history.
+If you need to undo changes that you have pushed, use linkgit:git-revert[1]
+instead.
+
+The git grep command can search for strings in any version of your
+project, so
+
+-------------------------------------
+$ git grep "hello" v2.5
+-------------------------------------
+
+searches for all occurrences of "hello" in v2.5.
+
+If you leave out the commit name, git grep will search any of the
+files it manages in your current directory. So
+
+-------------------------------------
+$ git grep "hello"
+-------------------------------------
+
+is a quick way to search just the files that are tracked by git.
+
+Many git commands also take sets of commits, which can be specified
+in a number of ways. Here are some examples with git log:
+
+-------------------------------------
+$ git log v2.5..v2.6 # commits between v2.5 and v2.6
+$ git log v2.5.. # commits since v2.5
+$ git log --since="2 weeks ago" # commits from the last 2 weeks
+$ git log v2.5.. Makefile # commits since v2.5 which modify
+ # Makefile
+-------------------------------------
+
+You can also give git log a "range" of commits where the first is not
+necessarily an ancestor of the second; for example, if the tips of
+the branches "stable-release" and "master" diverged from a common
+commit some time ago, then
+
+-------------------------------------
+$ git log stable..experimental
+-------------------------------------
+
+will list commits made in the experimental branch but not in the
+stable branch, while
+
+-------------------------------------
+$ git log experimental..stable
+-------------------------------------
+
+will show the list of commits made on the stable branch but not
+the experimental branch.
+
+The "git log" command has a weakness: it must present commits in a
+list. When the history has lines of development that diverged and
+then merged back together, the order in which "git log" presents
+those commits is meaningless.
+
+Most projects with multiple contributors (such as the linux kernel,
+or git itself) have frequent merges, and gitk does a better job of
+visualizing their history. For example,
+
+-------------------------------------
+$ gitk --since="2 weeks ago" drivers/
+-------------------------------------
+
+allows you to browse any commits from the last 2 weeks of commits
+that modified files under the "drivers" directory. (Note: you can
+adjust gitk's fonts by holding down the control key while pressing
+"-" or "+".)
+
+Finally, most commands that take filenames will optionally allow you
+to precede any filename by a commit, to specify a particular version
+of the file:
+
+-------------------------------------
+$ git diff v2.5:Makefile HEAD:Makefile.in
+-------------------------------------
+
+You can also use "git show" to see any such file:
+
+-------------------------------------
+$ git show v2.5:Makefile
+-------------------------------------
+
+Next Steps
+----------
+
+This tutorial should be enough to perform basic distributed revision
+control for your projects. However, to fully understand the depth
+and power of git you need to understand two simple ideas on which it
+is based:
+
+ * The object database is the rather elegant system used to
+ store the history of your project--files, directories, and
+ commits.
+
+ * The index file is a cache of the state of a directory tree,
+ used to create commits, check out working directories, and
+ hold the various trees involved in a merge.
+
+linkgit:gittutorial-2[7][Part two of this tutorial] explains the object
+database, the index file, and a few other odds and ends that you'll
+need to make the most of git.
+
+If you don't want to continue with that right away, a few other
+digressions that may be interesting at this point are:
+
+ * linkgit:git-format-patch[1], linkgit:git-am[1]: These convert
+ series of git commits into emailed patches, and vice versa,
+ useful for projects such as the linux kernel which rely heavily
+ on emailed patches.
+
+ * linkgit:git-bisect[1]: When there is a regression in your
+ project, one way to track down the bug is by searching through
+ the history to find the exact commit that's to blame. Git bisect
+ can help you perform a binary search for that commit. It is
+ smart enough to perform a close-to-optimal search even in the
+ case of complex non-linear history with lots of merged branches.
+
+ * link:everyday.html[Everyday GIT with 20 Commands Or So]
+
+ * linkgit:gitcvs-migration[7][git for CVS users].
+
+SEE ALSO
+--------
+linkgit:gittutorial-2[7],
+linkgit:gitcvs-migration[7],
+linkgit:gitcore-tutorial[7],
+linkgit:gitglossary[7],
+link:everyday.html[Everyday git],
+link:user-manual.html[The Git User's Manual]
+
+GIT
+---
+Part of the linkgit:git[1] suite.