Git usage

• Summary of git commands

User Infos

• set your used id and mail
  • git config --global user.name some.body
  • git config --global user.email some.body@cern.ch

File handling

• adding a file/directory
  • git add ./PATH/TO/SOMETHING
• removing from the local repository and from the disk
  • git rm ./PATH/TO/SOMETHING
  • just removing from the repository and keeping the file on disk
    • git rm --cached ./PATH/TO/SOMETHING
• moving
  • git mv ./PATH/TO/SOMETHING  ./PATH/TO/SOMEWHERE/ELSE

• commiting changes in the local repository
  • git commit -m "a comment what happened here" (with -a an implicit add is done)

Branches

• add a new branch OtherBranch
  • git branch OtherBranch

• to switch to another branch
  • git checkout  OtherBranch

Change Log and Tagging

• to see the history of changes in the current branch
  • git log

• check the specific changes that were applied in the commit with hash 123456789abcdefg1011121314
  • git show 123456789abcdefg1011121314

• to tag a certain change with the commit hash 123456789abcdefg1011121314
  • git tag TestTag1.1 123456789abcdefg1011121314
  • just git tag TestTag1.1 tags the most current change

Communicating with a remote repository/user

• see, which other users/repositories exist
  • git remote -v

• to push the from the local repository the branch BRANCH to the remote user origin
  • git push origin BRANCH

• to fetch from the remote repository origin the branch BRANCH and merge it into your local branch
  • git pull origin BRANCH
  • to fetch only the changes do, i.e. get only the information about remote updates without changing the actual local files
    • git fetch origin BRANCH
  • to do only a merge of changes from branch BRANCH into the local files of the active branch do
    • git merge BRANCH

ignoring files

• some files are probably not useful to be tracked, e.g. compiled libraries or binaries *.pyc,...
  • for a specific repository a =.gitignore=-file can be filled with the file names to be ignored
  • globally ignoring files in all repositories a file as .gitignore_global can be placed in the home directory and added to the git-configuration with git config --global core.excludesfile ~/.gitignore_global
    • the file could contain exclusions like

      *.o
      *.so
      *.pyc

• this should fix some of the git messages Your branch is ahead of 'origin/master' by # commits.

merging only smaller changes between branches

• for exchanging only small changes between branches, the cherry-pick command can be used, e.g. in a =beta=-branch a small bug-fix works and one would like to implement the fix already in the =master=-branch without merging the branches completely.
  • first: move to the =beta=-branch and check, in which commit the bug-fix was added.

    • git checkout beta
      git log -1

      • commit 67f90a0768efc5eb...
  • move to the master=-branch and =cherry-pick this commit to be merged
    • git cherry-pick 67f90a0768efc
  • (resolve any conflicts)