我们把在Git里常用的一些名词做了解释列在这里。这些名词(terms)全部来自[Git Glossary](http://www.kernel.org/pub/software/scm/git/docs/gitglossary.html)。 _alternate object database_ > Via the alternates mechanism, a repository > > ~~~ > can inherit part of its object database > from another object database, which is called "alternate". > > ~~~ _bare repository_ > A bare repository is normally an appropriately > > ~~~ > named directory with a `.git` suffix that does not > have a locally checked-out copy of any of the files under > revision control. That is, all of the `git` > administrative and control files that would normally be present in the > hidden `.git` sub-directory are directly present in the > `repository.git` directory instead, > and no other files are present and checked out. Usually publishers of > public repositories make bare repositories available. > > ~~~ _祼仓库_ > ~~~ > A bare repository is normally an appropriately > named directory with a `.git` suffix that does not > have a locally checked-out copy of any of the files under > revision control. That is, all of the `git` > administrative and control files that would normally be present in the > hidden `.git` sub-directory are directly present in the > `repository.git` directory instead, > and no other files are present and checked out. Usually publishers of > public repositories make bare repositories available. > > ~~~ _blob object（二进制对象）_ > 没有类型的数据对象。例如：一个文件的内容。 _branch_ > A "branch" is an active line of development. The most recent > > ~~~ > commit on a branch is referred to as the tip of > that branch. The tip of the branch is referenced by a branch > head, which moves forward as additional development > is done on the branch. A single git > repository can track an arbitrary number of > branches, but your working tree is > associated with just one of them (the "current" or "checked out" > branch), and HEAD points to that branch. > > ~~~ _分支_ > ~~~ > 一个“分支”是开发过程中的(active line)。。。。 > > ~~~ _cache（缓存）_ > 索引(index)的旧称(obsolete). _chain（链表）_ > 一串对象，其中每个对象都有指向其后继对象的引用(reference to its successor)。例如：一个提交(commit)的后继对象就是它的父对象。 _changeset（修改集）_ > BitKeeper/cvsps 里对于提交(commit)的说法。但是 git 只存储快照(states)，不存储修改；所以这个词用在 git 里有点不大合适。 _checkout（签出）_ > ~~~ > 用对象仓库(object database)里的一个树对象(tree object)更新当前整个工作树(worktree)，或者一个二进制对象(blob object)更新工作树的一部分；如果工作树指向了一个新的分支，那么就会更新索引(index)和HEAD。 > > ~~~ _cherry-picking_ > In SCM jargon, "cherry pick" means to choose a subset of > > ~~~ > changes out of a series of changes (typically commits) and record them > as a new series of changes on top of a different codebase. In GIT, this is > performed by the "git cherry-pick" command to extract the change introduced > by an existing commit and to record it based on the tip > of the current branch as a new commit. > > ~~~ _cherry-picking_ > 在SCM的行话里，“cherry pick“ 意味着从一系列的修改中选出一部分修改(通常是提交)，应用到当前代码中。() _clean（干净）_ > 如果一个工作树(working tree)中所有的修改都已提交到了当前分支里(current head)，那么就说它是干净的(clean)，反之它就是脏的(dirty)。 _commit_ > As a verb: The action of storing a new snapshot of the project's > > ~~~ > state in the git history, by creating a new commit representing the current > state of the index and advancing HEAD > to point at the new commit. > > ~~~ _commit（提交）_ > 作为名词：指向git历史的某一点的指针；整个项目的历史就由一组相互关联的提交组成的。提交(commit)在其它版本控制系统中也做"revision"或"version"。同时做为提交对象(commit object)的缩写。 > > 作为动词：创建一新的提交(commit)来表示当前索引(index)的状态的行为，把 HEAD 指向新创建的提交，这一系列把项目在某一时间上的快照(snapshot)保存在git历史中的操作。 _提交对象_ > 一个关于特定版本信息(particular revision)的对象。包括父对象名，提交者，作者，日期和存储了此版本内容的树对象名(tree object)。 _core git_ > Git的基本数据结构和工具，它只对外提供简单的代码管理工具。 _DAG_ > 有向无环图。众多提交对象(commit objects)组成了一个有向无环图；因为它们都有直接父对象(direct parent)，且没有一条提交线路(chain)的起点和终点都是同一个对象。 _dangling object（悬空对象）_ > 一个甚至从其它不可达对象也不可达的对象(unreachable object)；仓库里的一个悬空对象没有任何引用(reference)或是对象(object)引用它。 _detached HEAD（分离的HEAD）_ > 通常情况下HEAD里是存放当前分支的名字。然而 git 有时也允许你签出任意的一个提交(commit)，而不一定是某分支的最近的提交(the tip of any particular branch)；在这种情况下，HEAD就是处于分离的状态(detached)。 译者注：这时`.git/HEAD`中存储的就是签出的提交的SHA串值。 _dircache_ > 请参见索引(index)。 _directory（目录）_ > 执行"ls"命令所显示的结果 :-) _dirty（脏）_ > 一个工作树里有没有提交到当前分支里修改，那么我就说它是脏的(dirty)。 _ent_ > 某些人给树名(tree-ish)起的另外一个别名，这里`http://en.wikipedia.org/wiki/Ent_(Middle-earth)`有更详细的解释。最好不要使用这个名词，以免让大家糊涂。 _evil merge（坏的合并）_ > 如果一次合并引入一些不存在于任何父对象(parent)中的修改，那么就称它是一个坏的合并(evil merge)。 _fast forward_ > A fast-forward is a special type of merge where you have a > > ~~~ > revision and you are "merging" another > branch's changes that happen to be a descendant of what > you have. In such these cases, you do not make a new merge > commit but instead just update to his > revision. This will happen frequently on a > tracking branch of a remote > repository. > > ~~~ _快速向前_ > “fast-forward”是一种特殊的合并,()。 在这种情况下，并没有创建一个合并提交(merge commit)，只是更新了版本信息。 当本地分支是远端仓库(remote repository)的跟踪分支时，这种情况经常出现。 _fetch（抓取）_ > 抓取一个分支意味着：得到远端仓库(remote repository)分支的head ref，找出本地对象数据库所缺少的对象，并把它们下载下来。你可以参考一下 [git fetch](http://www.kernel.org/pub/software/scm/git/docs/git-fetch.html)。 _file system（文件系统）_ > Linus Torvalds 最初设计 git 时，是把它设计成一个在用户空间(user space)运行的文件系统；也就是一个用来保存文件和目录的 infrastructure，这样就保证了git的速度和效率。 _git archive_ > 对玩架构的人来说，这就是仓库的同义词。 _grafts_ > Grafts enables two otherwise different lines of development to be joined > > ~~~ > together by recording fake ancestry information for commits. This way > you can make git pretend the set of parents a commit has > is different from what was recorded when the commit was > created. Configured via the `.git/info/grafts` file. > > ~~~ _hash（哈希）_ > 在git里，这就是对象名(object name)的同义词。 _head_ > 指向一个分支最新提交的命名引用(named reference)。除非使用了打包引用(packed refs)，heads 一般存储在`$GIT_DIR/refs/heads/`。 参见: [git pack-refs](http://www.kernel.org/pub/software/scm/git/docs/git-pack-refs.html) _HEAD_ > 当前分支。详细的讲是：你的工作树(working tree)通是从HEAD所指向的tree所派生的来的。 HEAD 必须是指向一个你仓库里的head，除非你使用分离的HEAD(detached HEAD)。 _head ref_ > head的同义词。 _hook_ > During the normal execution of several git commands, call-outs are made > > ~~~ > to optional scripts that allow a developer to add functionality or > checking. Typically, the hooks allow for a command to be pre-verified > and potentially aborted, and allow for a post-notification after the > operation is done. The hook scripts are found in the > `$GIT_DIR/hooks/` directory, and are enabled by simply > removing the `.sample` suffix from the filename. In earlier versions > of git you had to make them executable. > > ~~~ _钩子_ > 在一些git命令的执行过程中, () 允许开发人员调用特别的脚本来添加功能或检查。 > > ~~~ > () > > ~~~ ~~~ Typically，钩子允许对一个命令做pre-verified并且可以中止此命令的运行；同时也可在这个命令执行完后做后继的通知工作。这些钩子脚本放在`$GIT_DIR/hooks/`目录下，你只要把这它们文件名的`.sample`后缀删掉就可以了。不过在git的早期版本，你需要为这些钩子脚本加上可执行属性。 ~~~ _index_ > A collection of files with stat information, whose contents are stored > > ~~~ > as objects. The index is a stored version of your > working tree. Truth be told, it can also contain a second, and even > a third version of a working tree, which are used > when merging. > > ~~~ _索引_ > 描述项目状态信息的文件，。索引里保存的是你的工作树的版本记录。() _index entry_ > The information regarding a particular file, stored in the > > ~~~ > index. An index entry can be unmerged, if a > merge was started, but not yet finished (i.e. if > the index contains multiple versions of that file). > > ~~~ _索引条目_ _主分支 (master)_ > 默认的开发分支。当你创建了一个git仓库，一个叫"master"的分支就被创建并且成为当前活动分支(active branch)。在多数情况下，这个分支里就包含有本地的开发内容。 _merge_ > As a verb: To bring the contents of another > > ~~~ > branch (possibly from an external > repository) into the current branch. In the > case where the merged-in branch is from a different repository, > this is done by first fetching the remote branch > and then merging the result into the current branch. This > combination of fetch and merge operations is called a > pull. Merging is performed by an automatic process > that identifies changes made since the branches diverged, and > then applies all those changes together. In cases where changes > conflict, manual intervention may be required to complete the > merge. > > ~~~ _merge（合并）_ > 作为动词：把另外一个分支(也许来自另外一个仓库)的内容合并进当前的分支。() > > 作为名词：除非合并的结果是 fast forward；那么一次成功的合并会创建一个新的提交(commit)来表示这次合并，并且把合并了的分支做为此提交(commit)的父对象。这个提交(commit)也可以表述为“合并提交”(merge commit)，或者就是"合并"(merge 名词)。 _object（对象）_ > Git的存储单位，它以对象内容的SHA1值做为唯一对象名；因此对象内容是不能被修改的。 _object database（对象仓库）_ > 用来存储一组对象(objects)，每个对象通过对象名来区别。对象(objects)通常保存在 `$GIT_DIR/objects/`。 _object identifier（对象标识符）_ > 对象名(object name)的同义词。 _object name（对象名）_ > 一个对象的唯一标识符(unique identifier)。它是使用SHA1算法(Secure Hash Algorithm 1)给对象内容进行哈希(hash)计算，产生的一个40个字节长的16进制编码的串。 _object type（对象类型）_ > Git有4种对象类型：提交(commit)，树(tree)，标签(tag)和二进制块(blob)。 _octopus（章鱼）_ > 一次多于两个分支的合并(merge)。也用来表示聪明的肉食动物。 _origin_ > 默认的上游仓库(upstream repository)。每个项目至少有一个它追踪(track)的上游(upstream)仓库，通常情况 origin 就是用来表示它。你可以用 ”｀git branch -r`“ 命令查看上游仓库(upstream repository)里所有的分支，再用 origin/name-of-upstream-branch 的名字来抓取(fetch)远程追踪分支里的内容。 _pack（包）_ > 一个文件，里面有一些压缩了的对象。(用以节约空间或是提高传输效率)。 _pack index（包索引）_ > 包(pack)里的一些标识符和其它相关信息，用于帮助git快速的访问包(pack)里面的对象。 _parent_ > A commit object contains a (possibly empty) list > > ~~~ > of the logical predecessor(s) in the line of development, i.e. its > parents. > > ~~~ _父对象_ > 一个提交对象(commit object)，()。 _pickaxe_ > The term pickaxe refers to an option to the diffcore > > ~~~ > routines that help select changes that add or delete a given text > string. With the `--pickaxe-all` option, it can be used to view the full > changeset that introduced or removed, say, a > particular line of text. See git diff. > > ~~~ _plumbing_ > core git的别名(cute name)。 _porcelain_ > Cute name for programs and program suites depending on > > ~~~ > core git, presenting a high level access to > core git. Porcelains expose more of a SCM > interface than the plumbing. > > ~~~ _pull（拉）_ > 拉(pull)一个分支意味着，把它抓取(fetch)下来并合并(merge)进当前的分支。可以参考 [git pull](http://www.kernel.org/pub/software/scm/git/docs/git-pull.html). _push_ > Pushing a branch means to get the branch's > > ~~~ > head ref from a remote repository, > find out if it is a direct ancestor to the branch's local > head ref, and in that case, putting all > objects, which are reachable from the local > head ref, and which are missing from the remote > repository, into the remote > object database, and updating the remote > head ref. If the remote head is not an > ancestor to the local head, the push fails. > > ~~~ _推_ > () _reachable_ > All of the ancestors of a given commit are said to be > > ~~~ > "reachable" from that commit. More > generally, one object is reachable from > another if we can reach the one from the other by a chain > that follows tags to whatever they tag, > commits to their parents or trees, and > trees to the trees or blobs > that they contain. > > ~~~ > > _可达的_ _rebase_ > 重新应用(reapply)当前点(branch)和另一个点(base)间的修改；并且根据rebase的结果重置当前分支的 head。 译者注：这个功能可以修改历史提交。 _ref（引用）_ > 一个40字节长的SHA1串或是表示某个对象的名字。它们可能存储在 `$GIT_DIR/refs/`。 _reflog_ > reflog用以表示本地的ref的历史记录。从另外一角度也可以说，它能行告诉你这个仓库最近的第3个版本(revision)是什么，还可以告诉你昨天晚上9点14分时你是在这个仓库的哪个分支下工作。可以参见:[git reflog](http://www.kernel.org/pub/software/scm/git/docs/git-reflog.html)。 _refspec_ > "refspec"用于描述在抓取和推的过程中，远程ref和本地ref之间的映射关系。它用冒号连接：:，前面也可以加一个加号：“+“。 例如：`git fetch $URL refs/heads/master:refs/heads/origin` 意味着：从$URL抓取主分支的 head 并把它保存到本地的origin分支的head中。`git push $URL refs/heads/master:refs/heads/to-upstream` 意味着：把我本地主分支 head 推到$URL上的 to-upstream分支里。具体可以参见： [git push](http://www.kernel.org/pub/software/scm/git/docs/git-push.html)。 _repository_ > A collection of refs together with an > > ~~~ > object database containing all objects > which are reachable from the refs, possibly > accompanied by meta data from one or more porcelains. A > repository can share an object database with other repositories > via alternates mechanism. > > ~~~ _resolve_ > 在自动合并失败后，手工修复合并冲突的行为。 _revision（版本）_ > 对象仓库(object database)保存的文件和目录在某一特定时间点的状态；它会被一个提交对象(commit object)所引用。 _rewind_ > 丢弃某一部分开发成果。例如：把head 指向早期的版本。 _SCM_ > 源代码管理工作。 _SHA1_ > 对象名(object name)的同义词。 _shallow repository_ > A shallow repository has an incomplete > > ~~~ > history some of whose commits have parents cauterized away (in other > words, git is told to pretend that these commits do not have the > parents, even though they are recorded in the commit > object). This is sometimes useful when you are interested only in the > recent history of a project even though the real history recorded in the > upstream is much larger. A shallow repository > is created by giving the `--depth` option to git clone, and > its history can be later deepened with git fetch. > > ~~~ _symref_ > Symbolic reference: instead of containing the SHA1 > > ~~~ > id itself, it is of the format 'ref: refs/some/thing' and when > referenced, it recursively dereferences to this reference. > 'HEAD' is a prime example of a symref. Symbolic > references are manipulated with the git symbolic-ref > command. > > ~~~ _tag（标签）_ > 一个ref指向一个标签或提交对象。与 head 相反，标签并不会在一次提交操作后改变。标签(不是标签对象)存储在`$GIT_DIR/refs/tags/`。 一个标签通常是用来标识提交家族链(commit ancerstry chain)里的某一点。 _tag object（标签对象）_ > 一个含有指向其它对象的引用(ref)的对象，对象里包括注释消息。如果它里面可以含有一个PGP签名，那么就称为一个“签名标签对象”(signed tag object)。 _topic branch_ > A regular git branch that is used by a developer to > > ~~~ > identify a conceptual line of development. Since branches are very easy > and inexpensive, it is often desirable to have several small branches > that each contain very well defined concepts or small incremental yet > related changes. > > ~~~ _tracking branch_ > A regular git branch that is used to follow changes from > > ~~~ > another repository. A tracking > branch should not contain direct modifications or have local commits > made to it. A tracking branch can usually be > identified as the right-hand-side ref in a Pull: > > ~~~ ~~~ refspec. ~~~ _追踪分支_ > 一个用以追踪(follow)另外一个仓库的修改的git分支。() _tree（树）_ > 可以是一个工作树(working tree)，也可以是一个树对象(tree object)。 _tree object（树对象）_ > 包含有一串(list)文件名和模式(mode)，并且指向与之相关的二进制对象(blob object)和树对象(tree object)。一个树(tree)等价于一个目录。 _tree-ish（树名）_ > 一个指向的提交对象(commit object)，树对象(tree object)或是标签对象(tag object)的引用(ref)。 _unmerged index（未合并索引）_ > 一个索引中包含有未合并的索引条目(index entries)。 _unreachable object（不可达对象）_ > 从任何一个分支、标签或是其它引用(reference)做为起点都无法到达的一个对象。 _working tree（工作树）_ > 签出(checkout)用于编辑的文件目录树。 工作树一般等价于 HEAD 加本地没有提交的修改。