Git advanced commands

Storing credentials

For our address you have to provide your user name and password every time you push or pull or clone something from the server. In order to avoid retyping your password every time you can let git store it locally for some time with the following commands (works for git since version 1.7.10)


$ git config --global credential.helper cache
$ git config --global credential.helper "cache --timeout=3600"

The last command sets the storage time to 1 hour. You can change this if you like.

WINDOWS (GitBash):

$ git config --global credential.helper wincred

Your credentials are going to be saved during the next access.

Working together with a svn repository

We have a few svn repositories in the Two!Ears project. You can also use git to work with those repositories. The only thing you have to use is the git-svn extension.

Now you can clone the svn repository

$ git svn clone

Do your changes and add them with standard git commits on your local PC. At the end you push all your changes to the remote svn repository via

$ git svn dcommit

In order to update your repository with changes from others you have to run

$ git svn rebase

Removing commits with large files

Use the BFG Repo-Cleaner to remove large files from your commit history. Just download the pre-compiled JAR file and copy it as bfg to a folder where your system looks for executables. Now let’s say you want to clean up the repository big-repo and remove all files larger than 2 MB, first create a local copy of it:

$ git clone --mirror /path/to/big-repo big-repo-copy
$ echo "Remove large files" > banned.txt
$ bfg --strip-blobs-bigger-than 2M --replace-text banned.txt repo.git
$ cd big-repo-copy
$ git reflog expire --expire=now --all && git gc --prune=now --aggressive
$ git push

For further infos on this topic have a look at the discussion on removing large files.

Split repository

If you want to split an existing repository into two, you can do it the following way. Assume we have the repository <big-repo> and want to extract a sub folder <name-of-folder>:

# prepare old repo
$ cd <big-repo>
$ git subtree split -P <name-of-folder> -b <name-of-new-branch>
$ cd ..
# create new repo
$ mkdir <new-repo>
$ cd <new-repo>
$ git init
$ git pull </path/to/big-repo> <name-of-new-branch>
# clean up
$ rm -rf .git/refs/original/ && \
  git reflog expire --all && \
  git gc --aggressive --prune=now
$ git reflog expire --all --expire-unreachable=0
$ git repack -A -d
$ git prune

Alternatively you could delete existing folders in your existing repository in order to create a new one out of it:

# clone the repo
$ git clone <big-repo> tmp.git
$ cd tmp.git
$ ls
 test1 test2
# remove original url
$ git remote rm origin
# Remove the folder test1 and all related commits from history
$ git filter-branch --force --index-filter \
  'git rm -r --cached --ignore-unmatch test1' --prune-empty \
  --tag-name-filter cat -- --all
# clean up space
$ git reflog expire --expire=now --all && git gc --prune=now --aggressive

After that you have your first new repository for which you can set up a new remote and push it. For the other part of the splitting repeat the above steps for the test2 folder.

For further details have a look at the discussion on how to split repositories.