X-Git-Url: https://git.phdru.name/?a=blobdiff_plain;f=pep-git.txt;h=118fc87a32b5a8b50de1b7ddf1f44c8c9eb2ab60;hb=afd0c6a745a6364a545abb8a72a767a78c4ed694;hp=5fe65656ee4751800ef6b2055ae24cb1e35c0f5f;hpb=0d79759c6e1fbf3346b1511af03a76ff24191e65;p=git-wiki.git diff --git a/pep-git.txt b/pep-git.txt index 5fe6565..118fc87 100644 --- a/pep-git.txt +++ b/pep-git.txt @@ -14,7 +14,7 @@ Abstract This Informational PEP collects information about git. There is, of course, a lot of documentation for git, so the PEP concentrates on -more complex issues, topics and scenarios. +more complex issues, scenarios and topics. The plan is to extend the PEP in the future collecting information about equivalence of Mercurial and git scenarios to help migrating @@ -75,7 +75,7 @@ Download and installation Unix users: download and install using your package manager. Microsoft Windows: download `git-for-windows -`_. +`_. MacOS X: use git installed with `XCode `_ or download @@ -86,13 +86,13 @@ Initial configuration --------------------- This simple code is often appears in documentation, but it is -important so let repeat it here:: +important so let repeat it here. Git marks every commit with author +and committer names/emails, so configure your real name and preferred +email:: $ git config --global user.name "User Name" $ git config --global user.email user.name@example.org -Put your real name and preferred email. - Examples in this PEP ==================== @@ -101,8 +101,8 @@ Examples of git commands in this PEP use the following approach. It is supposed that you, the user, works with a local repository named ``python`` that has an upstream remote repo named ``origin``. Your local repo has two branches ``v1`` and ``v2``. For most examples the -currently checked out branch is ``v2``. That is, it's assumed you did -something like that:: +currently checked out branch is ``v2``. That is, it's assumed you have +done something like that:: $ git clone -b v1 http://git.python.org/python.git $ cd python @@ -114,40 +114,42 @@ Branches and branches ===================== Git terminology can be a bit misleading. Take, for example, the term -"branch". In git it has two meanings. A branch is a directed chain of -commits (possible with merges). And a branch is a label or a pointer +"branch". In git it has two meanings. A branch is a directed line of +commits (possibly with merges). And a branch is a label or a pointer assigned to a line of commits. It is important to differentiate when -you talk about commits and when about their labels. Chains of commits -are unnamed and are usually only lengthening. Labels, on the other -hand, can be created, moved, renamed and deleted freely. +you talk about commits and when about their labels. Lines of commits +are by itself unnamed and are usually only lengthening and merging. +Labels, on the other hand, can be created, moved, renamed and deleted +freely. Remote repository and remote branches ===================================== -Another example of misleading terminology. A remote repository is -really remote, you access it via network (well, a remote repository -can be on your local disk, but it's still remote because it's not the -current repo). +Another example of slightly misleading terminology. Remote +repositories are really remote, you access them via network (well, a +remote repository can be on your local disk, but it's still remote +because it's not the current repo). Remote branches, on the other hand, are branches (pointers to commits) -in your local repository. They are there for git to remember what +in your local repository. They are there for you to remember what branches and commits have been pulled from and pushed to what remote -repos (you can pull from and push to many remotes). +repos (you can pull from and push to many remotes). Remote branches +live under ``remotes/REMOTE`` namespaces, e.g. ``remotes/origin/v2``. -To see the status of remote branches:: +To see the status of remote branches run:: $ git branch -rv -To see local and remote branches (and tags) pointing to commits run:: +To see local and remote branches (and tags) pointing to commits:: $ git log --decorate You never do your own development on remote branches. You create a -local branch that has a remote branch as an upstream and do -development on that local branch. On push git updates remote branches, -and on pull git updates remote branches and fast-forwards, merges or -rebases local branches. +local branch that has a remote branch as upstream and do development +on that local branch. On push git updates remote branches, and on pull +git updates remote branches and fast-forwards, merges or rebases local +branches. When you do an initial clone like this:: @@ -157,12 +159,138 @@ git clones remote repository ``http://git.python.org/python.git`` to directory ``python``, creates remote branches and checks out branch ``v1`` into the working directory. +Updating local and remote branches +---------------------------------- + +There is a major difference between + +:: + + $ git fetch REMOTE BRANCH + +and + +:: + + $ git fetch REMOTE BRANCH:BRANCH + +The first command fetches commits from the named BRANCH in the REMOTE +repository that are not in your repository and leaves the id (the +hash) of the head commit in file .git/FETCH_HEAD. But it doesn't +update any branch (doesn't move any pointer). + +The second command fetches commits from the named BRANCH in the REMOTE +repository that are not in your repository and updates both the local +branch BRANCH and its upstream remote branch. But it refuses to update +branches in case of non-fast-forward. And it refuses to update the +current branch. + +The first command is used internally by ``git pull``. + +:: + + $ git pull REMOTE BRANCH + +is equivalent to + +:: + + $ git fetch REMOTE BRANCH + $ git merge FETCH_HEAD # FETCH_HEAD is a literal here + +Certainly, BRANCH in that case should be your current branch. If you +want to merge a different branch into your current branch first update +that non-current branch and then merge:: + + $ git fetch origin v1:v1 # Update v1 + $ git pull --rebase origin v2 # Update the current branch v2 using + # rebase instead of merge + $ git merge v1 + +It is possible to configure git to make it fetch/pull a few branches +or all branches at once, so you can simply run + +:: + + $ git pull origin + +or even + +:: + + $ git pull + +Push +'''' + +Pushing is a bit simpler. There is only one command ``push``. When you +run + +:: + + $ git push origin v1 v2 + +git guesses (knowing upstream remote branches) that you really want + +:: + + $ git push origin v1:v1 v2:v2 + +Git pushes commits to the remote repo and updates remote branches. Git +refuses to push commits that aren't fast-forwardable. You can +force-push anyway, but please remember - you can force-push to your +own repositories but don't force-push to public or shared repos. If +you find git refuses to push commits that aren't fast-forwardable, +better fetch and merge commits from the remote repo (or rebase your +commits on top of the fetched commits), then push. Only force-push if +you know what you do and why you do it. See the section `Commit +editing and caveats`_ below. + +It is possible to configure git to make it push a few branches or all +branches at once, so you can simply run + +:: + + $ git push origin + +or even + +:: + + $ git push + +Git refuses to push a branch if it's the current branch in the remote +non-bare repository: git refuses to update remote working directory. +You really should push only to bare repositories. For non-bare +repositories git prefers pull-based workflow. + +Tags +'''' + +Git automatically fetches tags that point to commits being fetched +during fetch/pull. To fetch all tags (and commits they point to) run +``git fetch --tags origin``. To fetch some specific tags fetch them +explicitly:: + + $ git fetch origin tag NAME1 tag NAME2... + +For example:: + + $ git fetch origin tag 1.4.2 tag 2.1.7 + +Git doesn't automatically pushes tags. That allows you to have private +tags (lightweight tags are also private for a repo, they cannot be +pushed). To push tag(s) list them explicitly:: + + $ git push origin tag 1.4.2 + $ git push origin v1 v2 tag 2.1.7 + Commit editing and caveats ========================== A warning not to edit published (pushed) commits also appears in -documentation but it's also repeated here as it's very important. +documentation but it's repeated here anyway as it's very important. It is possible to recover from forced push but it's PITA for the entire team. Please avoid it. @@ -197,7 +325,7 @@ safely edit, remove, reorder, combine and split commits that hasn't been pushed yet. You can even push commits to your own (backup) repo, edit them later and force-push edited commits to replace what has already been pushed. Not a problem until commits are in a public -repository. +or shared repository. Undo @@ -224,15 +352,8 @@ Staging area aka index is a distinguishing feature of git. See Wiki. -Advanced configuration -====================== - -Line endings ------------- - -Git has builtin mechanisms to handle line endings. - -TODO: describe crlf configuration and .gitattributes. +Merge or rebase? +================ Null-merges @@ -244,12 +365,35 @@ Git has a builtin strategy for what Python core developers call $ git merge -s ours v1 # null-merge v1 into v2 +ReReRe +====== + +https://git-scm.com/book/en/Git-Tools-Rerere + + +Advanced configuration +====================== + +Line endings +------------ + +Git has builtin mechanisms to handle line endings. + +TODO: describe crlf configuration and .gitattributes. + + Database maintenance ==================== TODO: dangling objects, git gc, git repack. +Tips and tricks +=============== + +TODO: bash/zsh completion, bash/zsh prompt. + + From Mercurial to git =====================