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diff --git a/Documentation/gittutorial.txt b/Documentation/gittutorial.txt index d465aab64e..dee050567e 100644 --- a/Documentation/gittutorial.txt +++ b/Documentation/gittutorial.txt @@ -7,6 +7,7 @@ gittutorial - A tutorial introduction to git (for version 1.5.1 or newer) SYNOPSIS -------- +[verse] git * DESCRIPTION @@ -19,13 +20,22 @@ 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: +First, note that you can get documentation for a command such as +`git log --graph` with: ------------------------------------------------ -$ man git-diff +$ man git-log ------------------------------------------------ +or: + +------------------------------------------------ +$ git help log +------------------------------------------------ + +With the latter, you can use the manual viewer of your choice; see +linkgit:git-help[1] for more information. + 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: @@ -58,7 +68,7 @@ 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]: +current directory (note the '.'), with 'git add': ------------------------------------------------ $ git add . @@ -66,7 +76,7 @@ $ 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]: +repository with 'git commit': ------------------------------------------------ $ git commit @@ -85,15 +95,15 @@ $ 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: +using 'git diff' with the --cached option: ------------------------------------------------ $ git diff --cached ------------------------------------------------ -(Without --cached, linkgit:git-diff[1] will show you any changes that +(Without --cached, 'git diff' 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]: +summary of the situation with 'git status': ------------------------------------------------ $ git status @@ -117,7 +127,7 @@ $ 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 +Alternatively, instead of running 'git add' beforehand, you can use ------------------------------------------------ $ git commit -a @@ -136,9 +146,9 @@ 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 +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. @@ -274,7 +284,7 @@ same machine, wants to contribute. Bob begins with: ------------------------------------------------ -$ git clone /home/alice/project myrepo +bob$ git clone /home/alice/project myrepo ------------------------------------------------ This creates a new directory "myrepo" containing a clone of Alice's @@ -285,7 +295,7 @@ Bob then makes some changes and commits them: ------------------------------------------------ (edit files) -$ git commit -a +bob$ git commit -a (repeat as necessary) ------------------------------------------------ @@ -293,43 +303,94 @@ 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 +alice$ cd /home/alice/project +alice$ 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.) +then she may need to manually fix any conflicts. The "pull" command thus performs two operations: it fetches changes from a remote branch, then merges them into the current branch. +Note that in general, Alice would want her local changes committed before +initiating this "pull". If Bob's work conflicts with what Alice did since +their histories forked, Alice will use her working tree and the index to +resolve conflicts, and existing local changes will interfere with the +conflict resolution process (git will still perform the fetch but will +refuse to merge --- Alice will have to get rid of her local changes in +some way and pull again when this happens). + +Alice can peek at what Bob did without merging first, using the "fetch" +command; this allows Alice to inspect what Bob did, using a special +symbol "FETCH_HEAD", in order to determine if he has anything worth +pulling, like this: + +------------------------------------------------ +alice$ git fetch /home/bob/myrepo master +alice$ git log -p HEAD..FETCH_HEAD +------------------------------------------------ + +This operation is safe even if Alice has uncommitted local changes. +The range notation "HEAD..FETCH_HEAD" means "show everything that is reachable +from the FETCH_HEAD but exclude anything that is reachable from HEAD". +Alice already knows everything that leads to her current state (HEAD), +and reviews what Bob has in his state (FETCH_HEAD) that she has not +seen with this command. + +If Alice wants to visualize what Bob did since their histories forked +she can issue the following command: + +------------------------------------------------ +$ gitk HEAD..FETCH_HEAD +------------------------------------------------ + +This uses the same two-dot range notation we saw earlier with 'git log'. + +Alice may want to view what both of them did since they forked. +She can use three-dot form instead of the two-dot form: + +------------------------------------------------ +$ gitk HEAD...FETCH_HEAD +------------------------------------------------ + +This means "show everything that is reachable from either one, but +exclude anything that is reachable from both of them". + +Please note that these range notation can be used with both gitk +and "git log". + +After inspecting what Bob did, if there is nothing urgent, Alice may +decide to continue working without pulling from Bob. If Bob's history +does have something Alice would immediately need, Alice may choose to +stash her work-in-progress first, do a "pull", and then finally unstash +her work-in-progress on top of the resulting history. + 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 +alice$ 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: +With this, Alice can perform the first part of the "pull" operation +alone using the 'git fetch' command without merging them with her own +branch, using: ------------------------------------- -$ git fetch bob +alice$ 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 +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 +alice$ git log -p master..bob/master ------------------------------------- shows a list of all the changes that Bob made since he branched from @@ -339,14 +400,14 @@ After examining those changes, Alice could merge the changes into her master branch: ------------------------------------- -$ git merge bob/master +alice$ git merge bob/master ------------------------------------- -This `merge` can also be done by 'pulling from her own remote -tracking branch', like this: +This `merge` can also be done by 'pulling from her own remote-tracking +branch', like this: ------------------------------------- -$ git pull . remotes/bob/master +alice$ git pull . remotes/bob/master ------------------------------------- Note that git pull always merges into the current branch, @@ -355,7 +416,7 @@ regardless of what else is given on the command line. Later, Bob can update his repo with Alice's latest changes using ------------------------------------- -$ git pull +bob$ git pull ------------------------------------- Note that he doesn't need to give the path to Alice's repository; @@ -364,19 +425,19 @@ repository in the repository configuration, and that location is used for pulls: ------------------------------------- -$ git config --get remote.origin.url +bob$ 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 +(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 +bob$ git branch -r origin/master ------------------------------------- @@ -384,7 +445,7 @@ 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 +bob$ git clone alice.org:/home/alice/project myrepo ------------------------------------- Alternatively, git has a native protocol, or can use rsync or http; @@ -392,13 +453,13 @@ 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]. +linkgit:gitcvs-migration[7]. 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. +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: @@ -411,7 +472,7 @@ 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 +We can give this name to 'git show' to see the details about this commit. ------------------------------------- @@ -447,7 +508,7 @@ $ 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 +$ git tag v2.5 1b2e1d63ff ------------------------------------- you can refer to 1b2e1d63ff by the name "v2.5". If you intend to @@ -469,13 +530,13 @@ $ git reset --hard HEAD^ # reset your current branch and working 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 +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] +If you need to undo changes that you have pushed, use 'git revert' instead. -The git grep command can search for strings in any version of your +The 'git grep' command can search for strings in any version of your project, so ------------------------------------- @@ -484,7 +545,7 @@ $ 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 +If you leave out the commit name, 'git grep' will search any of the files it manages in your current directory. So ------------------------------------- @@ -494,7 +555,7 @@ $ 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: +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 @@ -504,32 +565,32 @@ $ 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 +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 +the branches "stable" and "master" diverged from a common commit some time ago, then ------------------------------------- -$ git log stable..experimental +$ git log stable..master ------------------------------------- -will list commits made in the experimental branch but not in the +will list commits made in the master branch but not in the stable branch, while ------------------------------------- -$ git log experimental..stable +$ git log master..stable ------------------------------------- will show the list of commits made on the stable branch but not -the experimental branch. +the master branch. -The "git log" command has a weakness: it must present commits in a +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 +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 +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, ------------------------------------- @@ -549,7 +610,7 @@ of the file: $ git diff v2.5:Makefile HEAD:Makefile.in ------------------------------------- -You can also use "git show" to see any such file: +You can also use 'git show' to see any such file: ------------------------------------- $ git show v2.5:Makefile @@ -571,16 +632,16 @@ is based: 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 +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. +need to make the most of git. You can find it at linkgit:gittutorial-2[7]. 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 + 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 @@ -590,9 +651,12 @@ digressions that may be interesting at this point are: smart enough to perform a close-to-optimal search even in the case of complex non-linear history with lots of merged branches. + * linkgit:gitworkflows[7]: Gives an overview of recommended + workflows. + * link:everyday.html[Everyday GIT with 20 Commands Or So] - * linkgit:gitcvs-migration[7][git for CVS users]. + * linkgit:gitcvs-migration[7]: Git for CVS users. SEE ALSO -------- @@ -600,6 +664,8 @@ linkgit:gittutorial-2[7], linkgit:gitcvs-migration[7], linkgit:gitcore-tutorial[7], linkgit:gitglossary[7], +linkgit:git-help[1], +linkgit:gitworkflows[7], link:everyday.html[Everyday git], link:user-manual.html[The Git User's Manual] |