path: root/Documentation/tutorial.txt
diff options
Diffstat (limited to 'Documentation/tutorial.txt')
1 files changed, 138 insertions, 88 deletions
diff --git a/Documentation/tutorial.txt b/Documentation/tutorial.txt
index b59094a..95ed852 100644
--- a/Documentation/tutorial.txt
+++ b/Documentation/tutorial.txt
@@ -36,14 +36,16 @@ To start up, create a subdirectory for it, change into that
subdirectory, and initialize the git infrastructure with `git-init-db`:
-mkdir git-tutorial
-cd git-tutorial
+$ mkdir git-tutorial
+$ cd git-tutorial
+$ git-init-db
to which git will reply
- defaulting to local storage area
+defaulting to local storage area
which is just git's way of saying that you haven't been doing anything
strange, and that it will have created a local `.git` directory setup for
@@ -114,8 +116,8 @@ in your git repository. We'll start off with a few bad examples, just to
get a feel for how this works:
-echo "Hello World" >hello
-echo "Silly example" >example
+$ echo "Hello World" >hello
+$ echo "Silly example" >example
you have now created two files in your working tree (aka 'working directory'), but to
@@ -137,7 +139,7 @@ adding a new entry with the `\--add` flag (or removing an entry with the
So to populate the index with the two files you just created, you can do
-git-update-index --add hello example
+$ git-update-index --add hello example
and you have now told git to track those two files.
@@ -146,12 +148,17 @@ In fact, as you did that, if you now look into your object directory,
you'll notice that git will have added two new objects to the object
database. If you did exactly the steps above, you should now be able to do
- ls .git/objects/??/*
+$ ls .git/objects/??/*
and see two files:
- .git/objects/55/7db03de997c86a4a028e1ebd3a1ceb225be238
- .git/objects/f2/4c74a2e500f5ee1332c86b94199f52b1d1d962
which correspond with the objects with names of 557db... and f24c7..
@@ -159,13 +166,17 @@ respectively.
If you want to, you can use `git-cat-file` to look at those objects, but
you'll have to use the object name, not the filename of the object:
- git-cat-file -t 557db03de997c86a4a028e1ebd3a1ceb225be238
+$ git-cat-file -t 557db03de997c86a4a028e1ebd3a1ceb225be238
where the `-t` tells `git-cat-file` to tell you what the "type" of the
object is. git will tell you that you have a "blob" object (ie just a
regular file), and you can see the contents with
- git-cat-file "blob" 557db03
+$ git-cat-file "blob" 557db03
which will print out "Hello World". The object 557db03 is nothing
more than the contents of your file `hello`.
@@ -202,7 +213,7 @@ In particular, let's not even check in the two files into git yet, we'll
start off by adding another line to `hello` first:
-echo "It's a new day for git" >>hello
+$ echo "It's a new day for git" >>hello
and you can now, since you told git about the previous state of `hello`, ask
@@ -210,7 +221,7 @@ git what has changed in the tree compared to your old index, using the
`git-diff-files` command:
+$ git-diff-files
Oops. That wasn't very readable. It just spit out its own internal
@@ -222,12 +233,7 @@ To make it readable, we can tell git-diff-files to output the
differences as a patch, using the `-p` flag:
-git-diff-files -p
-which will spit out
+$ git-diff-files -p
diff --git a/hello b/hello
index 557db03..263414f 100644
--- a/hello
@@ -264,13 +270,15 @@ filenames with their contents (and their permissions), and we're
creating the equivalent of a git "directory" object:
+$ git-write-tree
and this will just output the name of the resulting tree, in this case
(if you have done exactly as I've described) it should be
- 8988da15d077d4829fc51d8544c097def6644dbb
which is another incomprehensible object name. Again, if you want to,
you can use `git-cat-file -t 8988d\...` to see that this time the object
@@ -299,14 +307,16 @@ that's exactly what `git-commit-tree` spits out, we can do this
all with a sequence of simple shell commands:
-commit=$(echo 'Initial commit' | git-commit-tree $tree)
-git-update-ref HEAD $commit
+$ tree=$(git-write-tree)
+$ commit=$(echo 'Initial commit' | git-commit-tree $tree)
+$ git-update-ref HEAD $commit
which will say:
- Committing initial tree 8988da15d077d4829fc51d8544c097def6644dbb
+Committing initial tree 8988da15d077d4829fc51d8544c097def6644dbb
just to warn you about the fact that it created a totally new commit
that is not related to anything else. Normally you do this only *once*
@@ -349,7 +359,9 @@ didn't have anything to diff against.
But now we can do
- git-diff-index -p HEAD
+$ git-diff-index -p HEAD
(where `-p` has the same meaning as it did in `git-diff-files`), and it
will show us the same difference, but for a totally different reason.
@@ -360,7 +372,9 @@ are obviously the same, so we get the same result.
Again, because this is a common operation, you can also just shorthand
it with
- git diff HEAD
+$ git diff HEAD
which ends up doing the above for you.
@@ -396,7 +410,7 @@ work through the index file, so the first thing we need to do is to
update the index cache:
-git-update-index hello
+$ git-update-index hello
(note how we didn't need the `\--add` flag this time, since git knew
@@ -417,7 +431,7 @@ this wasn't an initial commit any more), but you've done that once
already, so let's just use the helpful script this time:
-git commit
+$ git commit
which starts an editor for you to write the commit message and tells you
@@ -450,7 +464,9 @@ give it just a single commit object, and it will figure out the parent
of that commit itself, and show the difference directly. Thus, to get
the same diff that we've already seen several times, we can now do
- git-diff-tree -p HEAD
+$ git-diff-tree -p HEAD
(again, `-p` means to show the difference as a human-readable patch),
and it will show what the last commit (in `HEAD`) actually changed.
@@ -505,13 +521,17 @@ activities.
To see the whole history of our pitiful little git-tutorial project, you
can do
- git log
+$ git log
which shows just the log messages, or if we want to see the log together
with the associated patches use the more complex (and much more
- git-whatchanged -p --root
+$ git-whatchanged -p --root
and you will see exactly what has changed in the repository over its
short history.
@@ -547,14 +567,16 @@ it in the `.git/refs/tags/` subdirectory instead of calling it a `head`.
So the simplest form of tag involves nothing more than
-git tag my-first-tag
+$ git tag my-first-tag
which just writes the current `HEAD` into the `.git/refs/tags/my-first-tag`
file, after which point you can then use this symbolic name for that
particular state. You can, for example, do
- git diff my-first-tag
+$ git diff my-first-tag
to diff your current state against that tag (which at this point will
obviously be an empty diff, but if you continue to develop and commit
@@ -568,7 +590,9 @@ you really did
that tag. You create these annotated tags with either the `-a` or
`-s` flag to `git tag`:
- git tag -s <tagname>
+$ git tag -s <tagname>
which will sign the current `HEAD` (but you can also give it another
argument that specifies the thing to tag, ie you could have tagged the
@@ -584,8 +608,8 @@ name for the state at that point.
Copying repositories
-git repositories are normally totally self-sufficient, and it's worth noting
-that unlike CVS, for example, there is no separate notion of
+git repositories are normally totally self-sufficient and relocatable
+Unlike CVS, for example, there is no separate notion of
"repository" and "working tree". A git repository normally *is* the
working tree, with the local git information hidden in the `.git`
subdirectory. There is nothing else. What you see is what you got.
@@ -602,8 +626,10 @@ This has two implications:
- if you grow bored with the tutorial repository you created (or you've
made a mistake and want to start all over), you can just do simple
- rm -rf git-tutorial
+$ rm -rf git-tutorial
and it will be gone. There's no external repository, and there's no
history outside the project you created.
@@ -618,8 +644,10 @@ Note that when you've moved or copied a git repository, your git index
file (which caches various information, notably some of the "stat"
information for the files involved) will likely need to be refreshed.
So after you do a `cp -a` to create a new copy, you'll want to do
- git-update-index --refresh
+$ git-update-index --refresh
in the new repository to make sure that the index file is up-to-date.
@@ -633,8 +661,10 @@ repositories you often want to make sure that the index cache is in some
known state (you don't know *what* they've done and not yet checked in),
so usually you'll precede the `git-update-index` with a
- git-read-tree --reset HEAD
- git-update-index --refresh
+$ git-read-tree --reset HEAD
+$ git-update-index --refresh
which will force a total index re-build from the tree pointed to by `HEAD`.
It resets the index contents to `HEAD`, and then the `git-update-index`
@@ -645,7 +675,9 @@ tells you they need to be updated.
The above can also be written as simply
- git reset
+$ git reset
and in fact a lot of the common git command combinations can be scripted
with the `git xyz` interfaces. You can learn things by just looking
@@ -665,20 +697,26 @@ first create your own subdirectory for the project, and then copy the
raw repository contents into the `.git` directory. For example, to
create your own copy of the git repository, you'd do the following
- mkdir my-git
- cd my-git
- rsync -rL rsync:// .git
+$ mkdir my-git
+$ cd my-git
+$ rsync -rL rsync:// .git
followed by
- git-read-tree HEAD
+$ git-read-tree HEAD
to populate the index. However, now you have populated the index, and
you have all the git internal files, but you will notice that you don't
actually have any of the working tree files to work on. To get
those, you'd check them out with
- git-checkout-index -u -a
+$ git-checkout-index -u -a
where the `-u` flag means that you want the checkout to keep the index
up-to-date (so that you don't have to refresh it afterward), and the
@@ -689,9 +727,11 @@ files).
Again, this can all be simplified with
- git clone rsync:// my-git
- cd my-git
- git checkout
+$ git clone rsync:// my-git
+$ cd my-git
+$ git checkout
which will end up doing all of the above for you.
@@ -719,7 +759,7 @@ used earlier, and create a branch in it. You do that by simply just
saying that you want to check out a new branch:
-git checkout -b mybranch
+$ git checkout -b mybranch
will create a new branch based at the current `HEAD` position, and switch
@@ -733,7 +773,7 @@ just telling `git checkout` what the base of the checkout would be.
In other words, if you have an earlier tag or branch, you'd just do
-git checkout -b mybranch earlier-commit
+$ git checkout -b mybranch earlier-commit
and it would create the new branch `mybranch` at the earlier commit,
@@ -743,27 +783,27 @@ and check out the state at that time.
You can always just jump back to your original `master` branch by doing
-git checkout master
+$ git checkout master
(or any other branch-name, for that matter) and if you forget which
branch you happen to be on, a simple
-ls -l .git/HEAD
+$ ls -l .git/HEAD
will tell you where it's pointing (Note that on platforms with bad or no
symlink support, you have to execute
-cat .git/HEAD
+$ cat .git/HEAD
instead). To get the list of branches you have, you can say
-git branch
+$ git branch
which is nothing more than a simple script around `ls .git/refs/heads`.
@@ -773,7 +813,7 @@ Sometimes you may wish to create a new branch _without_ actually
checking it out and switching to it. If so, just use the command
-git branch <branchname> [startingpoint]
+$ git branch <branchname> [startingpoint]
which will simply _create_ the branch, but will not do anything further.
@@ -792,9 +832,9 @@ being the same as the original `master` branch, let's make sure we're in
that branch, and do some work there.
-git checkout mybranch
-echo "Work, work, work" >>hello
-git commit -m 'Some work.' hello
+$ git checkout mybranch
+$ echo "Work, work, work" >>hello
+$ git commit -m 'Some work.' hello
Here, we just added another line to `hello`, and we used a shorthand for
@@ -807,7 +847,7 @@ does some work in the original branch, and simulate that by going back
to the master branch, and editing the same file differently there:
-git checkout master
+$ git checkout master
Here, take a moment to look at the contents of `hello`, and notice how they
@@ -815,9 +855,9 @@ don't contain the work we just did in `mybranch` -- because that work
hasn't happened in the `master` branch at all. Then do
-echo "Play, play, play" >>hello
-echo "Lots of fun" >>example
-git commit -m 'Some fun.' hello example
+$ echo "Play, play, play" >>hello
+$ echo "Lots of fun" >>example
+$ git commit -m 'Some fun.' hello example
since the master branch is obviously in a much better mood.
@@ -826,7 +866,9 @@ Now, you've got two branches, and you decide that you want to merge the
work done. Before we do that, let's introduce a cool graphical tool that
helps you view what's going on:
- gitk --all
+$ gitk --all
will show you graphically both of your branches (that's what the `\--all`
means: normally it will just show you your current `HEAD`) and their
@@ -840,7 +882,7 @@ script called `git merge`, which wants to know which branches you want
to resolve and what the merge is all about:
-git merge "Merge work in mybranch" HEAD mybranch
+$ git merge "Merge work in mybranch" HEAD mybranch
where the first argument is going to be used as the commit message if
@@ -851,6 +893,7 @@ merge will need to be fixed up by hand, though, so git will do as much
of it as it can automatically (which in this case is just merge the `example`
file, which had no differences in the `mybranch` branch), and say:
Trying really trivial in-index merge...
fatal: Merge requires file-level merging
@@ -859,6 +902,7 @@ file, which had no differences in the `mybranch` branch), and say:
ERROR: Merge conflict in hello.
fatal: merge program failed
Automatic merge failed/prevented; fix up by hand
which is way too verbose, but it basically tells you that it failed the
really trivial merge ("Simple merge") and did an "Automatic merge"
@@ -879,7 +923,7 @@ Work, work, work
and once you're happy with your manual merge, just do a
-git commit hello
+$ git commit hello
which will very loudly warn you that you're now committing a merge
@@ -929,17 +973,19 @@ to the `master` branch. Let's go back to `mybranch`, and run
resolve to get the "upstream changes" back to your branch.
-git checkout mybranch
-git merge "Merge upstream changes." HEAD master
+$ git checkout mybranch
+$ git merge "Merge upstream changes." HEAD master
This outputs something like this (the actual commit object names
would be different)
- Updating from ae3a2da... to a80b4aa....
- example | 1 +
- hello | 1 +
- 2 files changed, 2 insertions(+), 0 deletions(-)
+Updating from ae3a2da... to a80b4aa....
+ example | 1 +
+ hello | 1 +
+ 2 files changed, 2 insertions(+), 0 deletions(-)
Because your branch did not contain anything more than what are
already merged into the `master` branch, the resolve operation did
@@ -972,7 +1018,9 @@ followed by a `git merge`.
Fetching from a remote repository is done by, unsurprisingly,
`git fetch`:
- git fetch <remote-repository>
+$ git fetch <remote-repository>
One of the following transports can be used to name the
repository to download from:
@@ -1017,7 +1065,7 @@ This transport was designed for anonymous downloading. Like SSH
transport, it finds out the set of objects the downstream side
lacks and transfers (close to) minimum set of objects.
HTTP and HTTPS transport are used only for downloading. They
@@ -1047,7 +1095,9 @@ However -- it's such a common thing to `fetch` and then
immediately `resolve`, that it's called `git pull`, and you can
simply do
- git pull <remote-repository>
+$ git pull <remote-repository>
and optionally give a branch-name for the remote end as a second
@@ -1075,8 +1125,8 @@ the remote repository URL in a file under .git/remotes/
directory, like this:
-mkdir -p .git/remotes/
-cat >.git/remotes/linus <<\EOF
+$ mkdir -p .git/remotes/
+$ cat >.git/remotes/linus <<\EOF
@@ -1086,7 +1136,7 @@ The URL specified in such file can even be a prefix
of a full URL, like this:
-cat >.git/remotes/jgarzik <<\EOF
+$ cat >.git/remotes/jgarzik <<\EOF
@@ -1300,7 +1350,7 @@ project `my-git`. After logging into the remote machine, create
an empty directory:
-mkdir my-git.git
+$ mkdir my-git.git
Then, make that directory into a git repository by running
@@ -1308,7 +1358,7 @@ Then, make that directory into a git repository by running
`.git`, we do things slightly differently:
-GIT_DIR=my-git.git git-init-db
+$ GIT_DIR=my-git.git git-init-db
Make sure this directory is available for others you want your
@@ -1334,7 +1384,7 @@ Come back to the machine you have your private repository. From
there, run this command:
-git push <public-host>:/path/to/my-git.git master
+$ git push <public-host>:/path/to/my-git.git master
This synchronizes your public repository to match the named
@@ -1346,7 +1396,7 @@ repository. mirror network takes care of the
propagation to other publicly visible machines:
-git push
+$ git push
@@ -1361,7 +1411,7 @@ immutable once they are created, there is a way to optimize the
storage by "packing them together". The command
-git repack
+$ git repack
will do it for you. If you followed the tutorial examples, you
@@ -1387,7 +1437,7 @@ Once you have packed objects, you do not need to leave the
unpacked objects that are contained in the pack file anymore.
-git prune-packed
+$ git prune-packed
would remove them for you.