2 Title: Collecting information about git
5 Author: Oleg Broytman <phd@phdru.name>
8 Content-Type: text/x-rst
15 This Informational PEP collects information about git. There is, of
16 course, a lot of documentation for git, so the PEP concentrates on
17 more complex issues, scenarios and topics.
19 The plan is to extend the PEP in the future collecting information
20 about equivalence of Mercurial and git scenarios to help migrating
21 Python development from Mercurial to git.
23 The author of the PEP doesn't currently plan to write a Process PEP on
24 migration from Mercurial to git.
30 Git is accompanied with a lot of documentation, both online and
33 Documentation for starters
34 --------------------------
37 <https://www.kernel.org/pub/software/scm/git/docs/gittutorial.html>`_,
39 <https://www.kernel.org/pub/software/scm/git/docs/gittutorial-2.html>`_.
42 <https://www.kernel.org/pub/software/scm/git/docs/user-manual.html>`_.
43 `Everyday GIT With 20 Commands Or So
44 <https://www.kernel.org/pub/software/scm/git/docs/everyday.html>`_.
46 <https://www.kernel.org/pub/software/scm/git/docs/gitworkflows.html>`_.
49 <http://www-cs-students.stanford.edu/~blynn/gitmagic/index.html>`_,
50 also with a number of translations.
52 Advanced documentation
53 ----------------------
55 `Pro Git <https://git-scm.com/book>`_. The Book about git. Buy it at
56 Amazon or download in PDF, mobi, or ePub form. Has translations to
57 many different languages. Download Russian translation from `GArik
58 <https://github.com/GArik/progit/wiki>`_.
60 `Git Wiki <https://git.wiki.kernel.org/index.php/Main_Page>`_.
65 Git has builtin help: run ``git help TOPIC``. For example, run
66 ``git help git`` or ``git help help``.
72 Download and installation
73 -------------------------
75 Unix users: download and install using your package manager.
77 Microsoft Windows: download `git-for-windows
78 <https://git-for-windows.github.io/>`_.
80 MacOS X: use git installed with `XCode
81 <https://developer.apple.com/xcode/downloads/>`_ or download
83 <http://sourceforge.net/projects/git-osx-installer/files/>`_.
88 This simple code is often appears in documentation, but it is
89 important so let repeat it here. Git marks every commit with author
90 and commiter names/emails, so configure your real name and preferred
93 $ git config --global user.name "User Name"
94 $ git config --global user.email user.name@example.org
100 Examples of git commands in this PEP use the following approach. It is
101 supposed that you, the user, works with a local repository named
102 ``python`` that has an upstream remote repo named ``origin``. Your
103 local repo has two branches ``v1`` and ``v2``. For most examples the
104 currently checked out branch is ``v2``. That is, it's assumed you did
105 something like that::
107 $ git clone -b v1 http://git.python.org/python.git
109 $ git fetch origin v2:v2
113 Branches and branches
114 =====================
116 Git terminology can be a bit misleading. Take, for example, the term
117 "branch". In git it has two meanings. A branch is a directed line of
118 commits (possibly with merges). And a branch is a label or a pointer
119 assigned to a line of commits. It is important to differentiate when
120 you talk about commits and when about their labels. Lines of commits
121 are by itself unnamed and are usually only lengthening and merging.
122 Labels, on the other hand, can be created, moved, renamed and deleted
126 Remote repository and remote branches
127 =====================================
129 Another example of slightly misleading terminology. Remote
130 repositories are really remote, you access them via network (well, a
131 remote repository can be on your local disk, but it's still remote
132 because it's not the current repo).
134 Remote branches, on the other hand, are branches (pointers to commits)
135 in your local repository. They are there for you to remember what
136 branches and commits have been pulled from and pushed to what remote
137 repos (you can pull from and push to many remotes). Remote branches
138 live under ``remotes/REMOTE`` namespaces, e.g. ``remotes/origin/v2``.
140 To see the status of remote branches run::
144 To see local and remote branches (and tags) pointing to commits::
148 You never do your own development on remote branches. You create a
149 local branch that has a remote branch as an upstream and do
150 development on that local branch. On push git updates remote branches,
151 and on pull git updates remote branches and fast-forwards, merges or
152 rebases local branches.
154 When you do an initial clone like this::
156 $ git clone -b v1 http://git.python.org/python.git
158 git clones remote repository ``http://git.python.org/python.git`` to
159 directory ``python``, creates remote branches and checks out branch
160 ``v1`` into the working directory.
163 Commit editing and caveats
164 ==========================
166 A warning not to edit published (pushed) commits also appears in
167 documentation but it's also repeated here as it's very important.
169 It is possible to recover from forced push but it's PITA for the
170 entire team. Please avoid it.
172 To see what commits have not been published yet compare the head of the
173 branch with its upstream remote branch::
175 $ git log origin/v2..
176 $ git log origin/v1..v1
178 For every branch that has an upstream remote branch git maintains an
179 alias @{upstream} (short version @{u}), so the commands above can be
185 To see the status of all branches::
189 To compare the status of local branches with a remote repo::
191 $ git remote show origin
193 Read `how to recover from upstream rebase
194 <https://git-scm.com/docs/git-rebase#_recovering_from_upstream_rebase>`_.
195 It is in ``git help rebase``.
197 On the other hand don't be too afraid about commit editing. You can
198 safely edit, remove, reorder, combine and split commits that hasn't
199 been pushed yet. You can even push commits to your own (backup) repo,
200 edit them later and force-push edited commits to replace what has
201 already been pushed. Not a problem until commits are in a public
208 TODO: describe undo strategies: git reset, git revert, git checkout,
209 git reflog. "Commit early, commit often".
212 https://kernel.org/pub/software/scm/git/docs/howto/revert-a-faulty-merge.html
221 Staging area aka index is a distinguishing feature of git. See
223 <https://git.wiki.kernel.org/index.php/WhatIsTheIndex>`_ and
224 `IndexCommandQuickref
225 <https://git.wiki.kernel.org/index.php/IndexCommandQuickref>`_ in Git
229 Advanced configuration
230 ======================
235 Git has builtin mechanisms to handle line endings.
237 TODO: describe crlf configuration and .gitattributes.
243 Git has a builtin strategy for what Python core developers call
246 $ git merge -s ours v1 # null-merge v1 into v2
252 TODO: dangling objects, git gc, git repack.
258 TODO: bash/zsh completion, bash/zsh prompt.
261 From Mercurial to git
262 =====================
264 Mercurial for Git users https://mercurial.selenic.com/wiki/GitConcepts
266 https://github.com/felipec/git-remote-hg
268 https://hg-git.github.io/
280 This document has been placed in the public domain.
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