Update tutorial.txt branches/tags to use the nicer helper syntax

Teach people to use "git tag <tag-name>" instead of writing the current
HEAD by hand into the .git/refs/tags/<tag-name> file.  Most people
probably don't really want to know about how git does things internally.
This commit is contained in:
Linus Torvalds 2005-07-23 15:24:53 -07:00
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Коммит a7333f9e56
1 изменённых файлов: 31 добавлений и 21 удалений

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@ -472,10 +472,11 @@ A "light" tag is technically nothing more than a branch, except we put
it in the ".git/refs/tags/" subdirectory instead of calling it a "head".
So the simplest form of tag involves nothing more than
cat .git/HEAD > .git/refs/tags/my-first-tag
git tag my-first-tag
after which point you can use this symbolic name for that particular
state. You can, for example, do
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
@ -487,9 +488,9 @@ since you tagged it.
A "signed tag" is actually a real git object, and contains not only a
pointer to the state you want to tag, but also a small tag name and
message, along with a PGP signature that says that yes, you really did
that tag. You create these signed tags with
that tag. You create these signed tags with the "-s" flag to "git tag":
git tag <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
@ -620,7 +621,7 @@ repository, and checked it out.
---------------------
Branches in git are really nothing more than pointers into the git
object space from within the ",git/refs/" subdirectory, and as we
object space from within the ".git/refs/" subdirectory, and as we
already discussed, the HEAD branch is nothing but a symlink to one of
these object pointers.
@ -632,36 +633,45 @@ want (and indeed, subdirectories), but the convention is that the
and nothing enforces it.
To show that as an example, let's go back to the git-tutorial archive we
used earlier, and create a branch in it. You literally do that by just
creating a new SHA1 reference file, and switch to it by just making the
HEAD pointer point to it:
used earlier, and create a branch in it. You do that by simply just
saying that you want to check out a new branch:
cat .git/HEAD > .git/refs/heads/mybranch
ln -sf refs/heads/mybranch .git/HEAD
git checkout -b mybranch
and you're done.
will create a new branch based at the current HEAD position, and switch
to it.
Now, if you make the decision to start your new branch at some other
point in the history than the current HEAD, you usually also want to
actually switch the contents of your working directory to that point
when you switch the head, and "git checkout" will do that for you:
instead of switching the branch by hand with "ln -sf", you can just do
[ Side note: if you make the decision to start your new branch at some
other point in the history than the current HEAD, you can do so by
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 mybranch
git checkout -b mybranch earlier-branch
which will basically "jump" to the branch specified, update your working
directory to that state, and also make it become the new default HEAD.
and it would create the new branch "mybranch" at the earlier point,
and check out the state at that time. ]
You can always just jump back to your original "master" branch by doing
git checkout master
and if you forget which branch you happen to be on, a simple
(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
will tell you where it's pointing.
NOTE! 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]
which will simply _create_ the branch, but will not do anything further.
You can then later - once you decide that you want to actually develop
on that branch - switch to that branch with a regular "git checkout"
with the branchname as the argument.
Merging two branches
--------------------