Git

31 Dec 2015

Local git commands:

• git branch newBranchName
• git checkout moveToThisBranch
• one can go “up the tree” w/ git checkout HEAD^ repeatedly
  • git checkout HEAD~NUMBER, where NUMBER is the number of commits to go back
  • same applies to the HEAD’s parent ^ (caret), ^ or ^1 is previous HEAD where ^2 is the branch
• git merge otherBranch, creates one merged branch from 2 different branches
  • git merge SOURCE, for example if there are 2 branches br1, br2 and we’re on br1 you do git merge br2
• git rebase otherBranch, copies all commits from the other branch onto current branch
  • git rebase DESTINATION, for example if there are 2 branches br1, br2 and we want to rebase to br2 we go to br1 and do git rebase br2
• detached HEAD, when doing git checkout hash1235, as we are no longer in a specific “place”
  • HEAD is current place in the tree where we are
• force assignment master branch to 3 commits up using relative refs ~ operator: git branch -f master HEAD~3
• git reset HEAD^ rewrite history as there were no commits, only works on local commits
• git revert HEAD for remote/pushed changes
• git cherry-pick commit1/hash1 commit2/hash2 (…) selects only the commits desired
• git rebase -i , for interactive rebasing, squash commits means merging them into 1, pick means dropping the commits
• git commit –amend to update the commit message
• git tag tagName hash/branch, to freeze in time the git repo state
• git describe , to see information about the commits state between tags, output will be
  • tagName_numberOfCommits_gHashOfDescribedCommit

Remote git commands:

• git clone
• git fetch, gets remote changes and updates where the local repo points to, but it will not update the local repo
  • it will not change anything in the local
  • same refspec : works for both fetch and push, only in reverse
    • for fetch the source will be remote branch and destination will be local branch, they will get created if not present
    • for push the source will be the remote branch…
  • fetching with empty origin will just create the local branch git fetch origin :newBranch, from master
• in order to have git fetch and git merge/rebase/cherry-pick git provides a special command
• git pull
  • “is essentially shorthand for a git fetch followed by a merge of whatever branch was just fetched”
  • git pull –rebase does a fetch and then a rebase, as compared to default fetch & merge
• git push
  • share our awesome work with the world, or at least the ones fetching from the remote repo
  • specific settings depending on push.default and git version
  • git push , where git push origin master - origin is the name of the remote and master the place where the commits come from
    • then the local branch is not important
  • git push origin : , refspec identifying where to push from and to on the `origin`
  • git push origin :foo , we can delete the local branch remotely as no branch was present locally (empty origin)
• we can update the default tracking branch either remote or local
  • -b local_name, -u remote branch name (can be omitted if on that branch currently)

Other commands:

• git bisect, searching through history