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index d465aab64e367f1564793b74522d571433d5b53f..384972cb9bb4a04c55bd8c4796bcd3408e44d5e9 100644 (file)
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
------------------------------------------------
It is a good idea to introduce yourself to git with your name and
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 .
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
------------------------------------------------
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
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
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.
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
------------------------------------------------
(edit files)
-$ git commit -a
+bob$ git commit -a
(repeat as necessary)
------------------------------------------------
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
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 reviewing 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,
+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
+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
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:
-------------------------------------
-$ git pull . remotes/bob/master
+alice$ git pull . remotes/bob/master
-------------------------------------
Note that git pull always merges into the current branch,
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;
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
-------------------------------------
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;
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:
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.
-------------------------------------
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
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
-------------------------------------
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
-------------------------------------
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
# 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
commit some time ago, then
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
+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
+or git itself) have frequent merges, and 'gitk' does a better job of
visualizing their history. For example,
-------------------------------------
$ 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
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:
* 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
--------