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diff --git a/Documentation/tutorial.txt b/Documentation/tutorial.txt deleted file mode 100644 index 129c5c5f5b..0000000000 --- a/Documentation/tutorial.txt +++ /dev/null @@ -1,584 +0,0 @@ -A tutorial introduction to git -============================== - -This tutorial explains how to import a new project into git, make -changes to it, and share changes with other developers. - -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". Tell git that you want it to track -every file under the current directory (note the '.') with: - ------------------------------------------------- -$ git add . ------------------------------------------------- - -Finally, - ------------------------------------------------- -$ git commit ------------------------------------------------- - -will prompt you for a commit message, then record the current state -of all the files to the repository. - -Making changes --------------- - -Try modifying some files, then run - ------------------------------------------------- -$ git diff ------------------------------------------------- - -to review your changes. When you're done, tell git that you -want the updated contents of these files in the commit and then -make a commit, like this: - ------------------------------------------------- -$ git add file1 file2 file3 -$ git commit ------------------------------------------------- - -This will again prompt your for a message describing the change, and then -record the new versions of the files you listed. - -Alternatively, instead of running `git add` beforehand, you can use - ------------------------------------------------- -$ git commit -a ------------------------------------------------- - -which will automatically notice modified (but not new) files. - -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 ----------------------------- - -With git you have to explicitly "add" all the changed _content_ you -want to commit together. This can be done in a few different ways: - -1) By using 'git add <file_spec>...' - -This can be performed multiple times before a commit. Note that this -is not only for adding new files. Even modified files must be -added to the set of changes about to be committed. The "git status" -command gives you a summary of what is included so far for the -next commit. When done you should use the 'git commit' command to -make it real. - -Note: don't forget to 'add' a file again if you modified it after the -first 'add' and before 'commit'. Otherwise only the previous added -state of that file will be committed. This is because git tracks -content, so what you're really 'add'ing to the commit is the *content* -of the file in the state it is in when you 'add' it. - -2) By using 'git commit -a' directly - -This is a quick way to automatically 'add' the content from all files -that were modified since the previous commit, and perform the actual -commit without having to separately 'add' them beforehand. This will -not add content from new files i.e. files that were never added before. -Those files still have to be added explicitly before performing a -commit. - -But here's a twist. If you do 'git commit <file1> <file2> ...' then only -the changes belonging to those explicitly specified files will be -committed, entirely bypassing the current "added" changes. Those "added" -changes will still remain available for a subsequent commit though. - -However, for normal usage you only have to remember 'git add' + 'git commit' -and/or 'git commit -a'. - - -Viewing the changelog ---------------------- - -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, you 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 commandline. - -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/bob/myrepo -------------------------------------- - -(The complete configuration created by git-clone is visible using -"git config -l", and the gitlink: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 gitlink: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 gitlink:git-push[1] and -link:cvs-migration.html[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 -gitlink: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 gitlink: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. - -link:tutorial-2.html[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 consider with that right away, a few other -digressions that may be interesting at this point are: - - * gitlink:git-format-patch[1], gitlink: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. - - * gitlink: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] - - * link:cvs-migration.html[git for CVS users]. |