X-Git-Url: https://git.phdru.name/?a=blobdiff_plain;f=pep-git.txt;h=60d08b65cd08da824ce1a8b049740a6fe60bebed;hb=56f550d92dde40538303f0011fa67cb276f197de;hp=43e8ddd63a408e6e01ecac5c2ef5dab9b1b7951a;hpb=aef095b9ca8c6fdc71be1b1d05dd28ceb672ab37;p=git-wiki.git diff --git a/pep-git.txt b/pep-git.txt index 43e8ddd..60d08b6 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, scenarios and topics. +more complex issues, scenarios and examples. The plan is to extend the PEP in the future collecting information about equivalence of Mercurial and git scenarios to help migrating @@ -30,6 +30,7 @@ Documentation Git is accompanied with a lot of documentation, both online and offline. + Documentation for starters -------------------------- @@ -45,12 +46,13 @@ Git Tutorial: `part 1 `Git workflows `_. + Advanced documentation ---------------------- `Git Magic `_, -also with a number of translations. +with a number of translations. `Pro Git `_. The Book about git. Buy it at Amazon or download in PDF, mobi, or ePub form. Has translations to @@ -59,6 +61,7 @@ many different languages. Download Russian translation from `GArik `Git Wiki `_. + Offline documentation --------------------- @@ -92,6 +95,7 @@ written in Python and GPL licensed. Linux, Windows, MacOS X. `TortoiseGit `_ is a Windows Shell Interface to Git based on TortoiseSVN; open source. + Initial configuration --------------------- @@ -180,9 +184,11 @@ When you do an initial clone like this:: $ git clone -b v1 http://git.python.org/python.git git clones remote repository ``http://git.python.org/python.git`` to -directory ``python``, creates remote-tracking branches, creates a -local branch ``v1``, configure it to track upstream remotes/origin/v1 -branch and checks out ``v1`` into the working directory. +directory ``python``, creates a remote named ``origin``, creates +remote-tracking branches, creates a local branch ``v1``, configure it +to track upstream remotes/origin/v1 branch and checks out ``v1`` into +the working directory. + Updating local and remote-tracking branches ------------------------------------------- @@ -208,7 +214,8 @@ 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-tracking branch. But it refuses to update branches in case of non-fast-forward. And it -refuses to update the current branch. +refuses to update the current branch (currently checked out branch, +where HEAD is pointing to). The first command is used internally by ``git pull``. @@ -353,9 +360,14 @@ tags. To push tags list them explicitly:: $ git push origin tag 1.4.2 $ git push origin v1 master tag 2.1.7 +Or push all tags at once:: + + $ git push --tags origin + Don't move tags with ``git tag -f`` or remove tags with ``git tag -d`` after they have been published. + Private information ''''''''''''''''''' @@ -417,6 +429,7 @@ Undo Whatever you do, don't panic. Almost anything in git can be undone. + git checkout: restore file's content ------------------------------------ @@ -432,6 +445,7 @@ i.e. ``git checkout README`` restores README to the latest commit. (Do not use ``git checkout`` to view a content of a file in a commit, use ``git cat-file -p``; e.g. ``git cat-file -p HEAD~:path/to/README``). + git reset: remove (non-pushed) commits -------------------------------------- @@ -447,6 +461,7 @@ Default is mixed. ProGit `explains difference very clearly. Bare repositories don't have indices or working trees so in a bare repo only soft reset is possible. + Unstaging ''''''''' @@ -456,6 +471,7 @@ committing. See `The Book `_ for details about unstaging and other undo tricks. + git reflog: reference log ------------------------- @@ -498,6 +514,7 @@ do something like:: $ git cherry-pick save-master~ save-master $ git branch -D save-master # remove temporary branch + git revert: revert a commit --------------------------- @@ -513,6 +530,7 @@ undo the code created by the merge commit but it cannot undo the fact of merge. See the discussion `How to revert a faulty merge `_. + One thing that cannot be undone ------------------------------- @@ -641,7 +659,7 @@ Staging area Staging area aka index aka cache is a distinguishing feature of git. Staging area is where git collects patches before committing them. Separation between collecting patches and commit phases provides a -very useful feature of git: one can review collected patches before +very useful feature of git: you can review collected patches before commit and even edit them - remove some hunks, add new hunks and review again. @@ -651,7 +669,7 @@ new (untracked) files. To simplify committing in case you just want to commit everything without reviewing run ``git commit --all`` (or just ``-a``) - the command adds every changed tracked file to the index and then commit. To commit a file or files regardless of patches collected -in the index run ``git commit [--only] -- $FILE...``. +in the index run ``git commit [--only|-o] -- $FILE...``. To add hunks of patches to the index use ``git add --patch`` (or just ``-p``). To remove collected files from the index use ``git reset HEAD @@ -662,7 +680,7 @@ To see the diff between the index and the last commit (i.e., collected patches) use ``git diff --cached``. To see the diff between the working tree and the index (i.e., uncollected patches) use just ``git diff``. To see the diff between the working tree and the last commit -(i.e., both collected and uncollected patches) use ``git diff HEAD``. +(i.e., both collected and uncollected patches) run ``git diff HEAD``. See `WhatIsTheIndex `_ and @@ -674,40 +692,169 @@ Wiki. ReReRe ====== -https://git-scm.com/book/en/Git-Tools-Rerere +Rerere is a mechanism that helps to resolve repeated merge conflicts. +The most frequent source of recurring merge conflicts are topic +branches that are merged into mainline and then the merge commits are +removed; that's often performed to test the topic branches and train +rerere; merge commits are removed to have clean linear history and +finish the topic branch with only one last merge commit. +Rerere works by remembering the states of tree before and after a +successful commit. That way rerere can automatically resolve conflicts +if they appear in the same files. -Database maintenance -==================== +Rerere can be used manually with ``git rerere`` command but most often +it's used automatically. Enable rerere with these commands in a +working tree:: + + $ git config rerere.enabled true + $ git config rerere.autoupdate true -TODO: dangling objects, git gc, git repack. +You don't need to turn rerere on globally - you don't want rerere in +bare repositories or repositories without branches; you only need +rerere in repos where you often perform merges and resolve merge +conflicts. -https://gcc.gnu.org/ml/gcc/2007-12/msg00165.html +See `Rerere `_ in The +Book. -http://vcscompare.blogspot.ru/2008/06/git-repack-parameters.html + +Database maintenance +==================== + +Git object database and other files/directories under ``.git`` require +periodic maintenance and cleanup. For example, commit editing left +unreferenced objects (dangling objects, in git terminology) and these +objects should be pruned to avoid collecting cruft in the DB. The +command ``git gc`` is used for maintenance. Git automatically runs +``git gc --auto`` as a part of some commands to do quick maintenance. +Users are recommended to run ``git gc --aggressive`` from time to +time; ``git help gc`` recommends to run it every few hundred +changesets; for more intensive projects it should be something like +once a week and less frequently (biweekly or monthly) for lesser +active projects. + +``git gc --aggressive`` not only removes dangling objects, it also +repacks object database into indexed and better optimized pack(s); it +also packs symbolic references (branches and tags). Another way to do +it is to run ``git repack``. + +There is a well-known `message +`_ from Linus +Torvalds regarding "stupidity" of ``git gc --aggressive``. The message +can safely be ignored now. It is old and outdated, ``git gc +--aggressive`` became much better since that time. + +For those who still prefer ``git repack`` over ``git gc --aggressive`` +the recommended parameters are ``git repack -a -d -f --depth=20 +--window=250``. See `this detailed experiment +`_ +for explanation on the effects of these parameters. + +From time to time run ``git fsck [--strict]`` to verify integrity of +the database. ``git fsck`` may produce a list of dangling objects; +that's not an error, just a reminder to perform regular maintenance. Tips and tricks =============== -TODO: sticky options; example: git grep -O. +Command-line options and arguments +---------------------------------- -TODO: tricky options; example: git log -p3. +`git help cli +`_ +recommends not to combine short options/flags. Most of the times it +works: ``git commit -av`` works perfectly, but there are situations +when it doesn't. E.g., ``git log -p -5`` cannot be combined as ``git +log -p5``. -TODO: bash/zsh completion, bash/zsh prompt. -https://git.kernel.org/cgit/git/git.git/tree/contrib/completion +Some options have arguments, some even have default arguments. In that +case the argument for such option must be spelled in a sticky way: +``-Oarg``, never ``-O arg`` because for an option that has a default +argument the latter means "use default value for option ``-O`` and +pass ``arg`` further to the option parser". For example, ``git grep`` +has an option ``-O`` that passes found files to a program; default +program for ``-O`` is pager (usually ``less``), but you can use your +editor:: + $ git grep -Ovim # but not -O vim -git on server -============= +BTW, there is a difference between running ``git grep -O`` and ``git +grep -Oless`` - in the latter case ``git grep`` passes ``+/pattern`` +option to less. + + +bash/zsh completion +------------------- + +It's a bit hard to type ``git rebase --interactive --preserve-merges +HEAD~5`` manually even for those who are happy to use command-line, +and this is where shell completion is of great help. Bash/zsh come +with programmable completion, often automatically preinstalled and +enabled, so if you have bash/zsh and git installed, chances are you +are already done - just go and use it at the command-line. -TODO: anonymous access; git over ssh; gitolite; gitweb; cgit; gitlab. +If you don't have necessary bits preinstalled, install and enable +bash_completion package. If you want to upgrade your git completion to +the latest and greatest download necessary file from `git contrib +`_. -http://gitolite.com/gitolite/index.html +Git-for-windows comes with git-bash for which bash completion is +installed and enabled. + + +bash/zsh prompt +--------------- + +For command-line lovers shell prompt can carry a lot of useful +information. To include git information in the prompt use +`git-prompt.sh +`_. +Read the detailed instructions in the file. + +Search the Net for "git prompt" to find other prompt variants. + + +git on server +============= -https://git.kernel.org/cgit/git/git.git/tree/gitweb +The simplest way to publish a repository or a group of repositories is +``git daemon``. The daemon provides anonymous access, by default it is +read-only. The repositories are accessible by git protocol (git:// +URLs). Write access can be enabled but the protocol lacks any +authentication means, so it should be enabled only within a trusted +LAN. See ``git help daemon`` for details. + +Git over ssh provides authentication and repo-level authorisation as +repositories can be made user- or group-writeable (see parameter +``core.sharedRepository`` in ``git help config``). If that's too +permissive or too restrictive for some project's needs there is a +wrapper `gitolite `_ that can +be configured to allow access with great granularity; gitolite has a +lot of documentation. + +Web interface to browse repositories can be created using `gitweb +`_ and `cgit +`_. Both are CGI scripts (written in +Perl and C). In addition to web interface both provide read-only dumb +http access for git (http(s):// URLs). + +There are also more advanced web-based development environments that +include ability to manage users, groups and projects; private, group +and public repositories; and often include issue trackers, wiki pages, +pull requests and other tools for development and communication. Among +these environments are `Kallithea `_ and +`pagure `_, both are written in Python; pagure was +written by Fedora developers and is being used to develop some Fedora +projects. `Gogs `_ is written in Go; there is a fork +`Gitea `_. + +And last but not least `Gitlab `_. It's +perhaps the most advanced git web-based development environment. +Written in Ruby, community edition is free and open source (MIT +license). -http://git.zx2c4.com/cgit/ From Mercurial to git =====================