git for me
I use git for my own projects, and the day-by-day stuff does not involve much messing with remote repositories. Anyway, it's a fantastic tool to keep track of the code and avoid losing anything.
getting started (installation apart!)
In the directory for the new project, just
git init Initialized empty Git repository in ...
At this point, there's nothing tracked, so after editing some files you can add whatever you want to track, either by filename or by directory name. The fastest thing to do is probably:
git add .
Note that at this point nothing has actually been put inside the
tracking system - you'll have to
commit your change:
You'll be asked to enter a commit log line and possibly something more, but it's higly probable that at this stage you'll want to always use the same message like this:
git commit -m 'initial import'
We'll talk a bit more about
commit in seeking and committing below.
When there are files in your directory that you don't want to track (e.g.
some tar archive), git will keep telling you about them. You can turn this
whining off by adding elements to the
echo '*.tar.gz' >> .git/info/exclude echo '*.swp' >> .git/info/exclude
seeking and committing
To see what's going on:
or, to have an idea of the changes:
git diff --color
In the last case, you can also provide some file names to restrict the
git diff --color path/to/file
After you have an idea of the log line to write, you can commit:
git commit path/to/file -m "your log line here"
-m parameter you enter interactive mode to provide a log
line and some more log details.
To commit all files just use
-a instead of passing the file name.
If you want to select all files in the commit, you can first add them:
git add file1 ... git add file2 git add path/to/file3
and then just commit:
git commit -m 'some complex commit'
Sometimes it's useful to set a tag in certain stable conditions. This can be done automatically by Dist::Zilla, for example.
To add a tag at the current HEAD:
git tag name-of-tag
If you want to put a tag in the past, just find out the SHA1 digest
of the commit with the
git log ... commit 1a9529d56959f7ad9287faaf3b143649516fa63f Author: Flavio Poletti <email@example.com> Date: Mon May 31 17:36:22 2010 +0200 turned complete-check in pure Perl ...
and use that:
git tag name-of-tag 1a9529d56959f7ad9287faaf3b143649516fa63f
You don't usually have to use the full SHA1, as long as git can be sure of what you're referring to. Usually some 8-10 characters suffice:
git tag name-of-tag 1a9529d569
getting a previous version of a file
If you want to get some previous version of a file, you first have to seek the right version. You can either get a commit or a tag, then:
git checkout name-of-tag path/to/file
You can use the commit SHA1 instead of name-of-tag. If you want to refer to some near version, you can refer to HEAD:
git checkout HEAD^ path/to/file # one step back git checkout HEAD^^ path/to/file # HEAD - 2 git checkout HEAD~5 path/to/file # HEAD - 5
If you want to make some experiments without messing up with the main trunk you can create a branch. To fork at the current point, you can just create the branch and switch to it:
git branch branch-name-here git checkout branch-name-here
To do these two operations in a single step (which is what you want 99%
of the times) just add
-b to checkout:
git checkout -b branch-name-here
You can also branch somewhere in the past, i.e. at a tag or specific SHA1:
git checkout -b branch-name-here name-of-tag
When you're happy with the branch status and your modifications, you can merge them back in the main trunk:
git checkout master git merge branch-name-here
At this point, you can also get rid of the branch if you want:
git branch -d branch-name-here
If you don't want to get all the changes in a branch, but just some of them,
cherry-pick instead. Cherry-picking means picking exactly the
commits that you want, so you have to know them beforehand (e.g. via
log command, see example above in the tag section):
git cherry-pick 1a9529d569 git cherry-pick c8878c0b
In this case, the
master branch and the new branch will not be aligned,
so git will complain if you try to get rid of the new branch. If you're
positive to get rid of it anyway, you can use
-D instead of
git branch -D branch-name-here
Note that there's no turning back, so be sure that you can actually get rid of the branch.
When you're merging a set of changes from a branch (either
cherry-pick-ing) you might want to aggregate them all under a single
commit, i.e. you might not be interested in the whole history for the
change (which might include lots of try-and-error commits) but you would
rather set a single, comprehensive log message.
In this case, what to do depends on the commits you're interested into. If you want
to do a
merge from some
branch-name-here, then you can use the
--no-ff switch (which is explained perfectly here):
git merge --no-ff branch-name-here -m 'Added frozzbuzz feature, yay!'
On the other hand, if you just want to
cherry-pick some modifications,
will be of help:
git cherry-pick --no-commit 1a9529d569 git cherry-pick --no-commit c8878c0b git commit -a -m 'Added long-wanted frozzbuzz feature, yay!'
cherry-pick this option can be abbreviated to
-n. Beware that
merge has a
--no-commit option too, but it does not seem to work (or it does not do what one
would expect, anyway), so stick to
--no-ff in the
[Edit] I know that there is another method that is more streamline and clean, but I just don't remember where I did see it at the moment!
It's not unusual that I have to use more than one computer - I have two at work and at least another one at home. You could argue that using three laptops is a bit weird, but this is life.
One thing that I tend to do quite early is duplicate a repository that I create locally on one of the three computers in a remote server, in order to be able to work on it from other computers when needed. For this, I found a blog post that is very useful, I'll try to mirror some of the contents here.
We're assuming that you already have your local repository
local:/home/foo/project and you have ssh access to the remote server. First of all create a bare repository in the remote server:
remote:/home/bar$ mkdir project remote:/home/bar$ cd project remote:/home/bar/project$ git init --bare
Now you can perform other initialisation stuff, e.g. permissions, configurations, etc.
Back on the local computer:
local:/home/foo/project$ git remote add origin ssh://user@remote:/home/bar/project local:/home/foo/project$ git push origin master
Of course you can also push whatever other branch you're interested into replicating in the remote server. At this point you need to set the branch as tracking the remote one, which can be done in several ways but I always stick to the suggestion in the link above:
local:/home/foo/project$ git checkout origin/master local:/home/foo/project$ git branch -f master origin/master local:/home/foo/project$ git checkout master
Again, repeat the first two steps for whatever branch you need. Done!
Some time ago I read that there should be also some other method, but one is sufficient and I don't find where!