1 alternate object database::
2 Via the alternates mechanism, a repository can inherit part of its
3 object database from another object database, which is called
7 A bare repository is normally an appropriately named
8 directory with a `.git` suffix that does not have a
9 locally checked-out copy of any of the files under revision
10 control. That is, all of the `git` administrative and
11 control files that would normally be present in the
12 hidden `.git` sub-directory are directly present in
13 the `repository.git` directory instead, and no other files
14 are present and checked out. Usually publishers of public
15 repositories make bare repositories available.
18 Untyped object, e.g. the contents of a file.
21 A non-cyclical graph of revisions, i.e. the complete history of
22 a particular revision, which is called the branch head. The
23 branch heads are stored in `$GIT_DIR/refs/heads/`.
29 A list of objects, where each object in the list contains a
30 reference to its successor (for example, the successor of a commit
31 could be one of its parents).
34 BitKeeper/cvsps speak for "commit". Since git does not store
35 changes, but states, it really does not make sense to use
36 the term "changesets" with git.
39 The action of updating the working tree to a revision which was
40 stored in the object database.
43 In SCM jargon, "cherry pick" means to choose a subset of
44 changes out of a series of changes (typically commits)
45 and record them as a new series of changes on top of
46 different codebase. In GIT, this is performed by
47 "git cherry-pick" command to extract the change
48 introduced by an existing commit and to record it based
49 on the tip of the current branch as a new commit.
52 A working tree is clean, if it corresponds to the revision
53 referenced by the current head. Also see "dirty".
56 As a verb: The action of storing the current state of the index in the
57 object database. The result is a revision.
58 As a noun: Short hand for commit object.
61 An object which contains the information about a particular
62 revision, such as parents, committer, author, date and the
63 tree object which corresponds to the top directory of the
67 Fundamental data structures and utilities of git. Exposes only
68 limited source code management tools.
71 Directed acyclic graph. The commit objects form a directed acyclic
72 graph, because they have parents (directed), and the graph of commit
73 objects is acyclic (there is no chain which begins and ends with the
77 An unreachable object which is not reachable even from other
78 unreachable objects; a dangling object has no references to it
79 from any reference or object in the repository.
82 You are *waaaaay* behind.
85 A working tree is said to be dirty if it contains modifications
86 which have not been committed to the current branch.
89 The list you get with "ls" :-)
92 Favorite synonym to "tree-ish" by some total geeks. See
93 `http://en.wikipedia.org/wiki/Ent_(Middle-earth)` for an in-depth
94 explanation. Avoid this term, not to confuse people.
97 A fast-forward is a special type of merge where you have
98 a revision and you are "merging" another branch's changes
99 that happen to be a descendant of what you have.
100 In such these cases, you do not make a new merge commit but
101 instead just update to his revision. This will happen
102 frequently on a tracking branch of a remote repository.
105 Fetching a branch means to get the branch's head ref from a
106 remote repository, to find out which objects are missing from
107 the local object database, and to get them, too.
110 Linus Torvalds originally designed git to be a user space file
111 system, i.e. the infrastructure to hold files and directories.
112 That ensured the efficiency and speed of git.
115 Synonym for repository (for arch people).
118 Grafts enables two otherwise different lines of development to be
119 joined together by recording fake ancestry information for commits.
120 This way you can make git pretend the set of parents a commit
121 has is different from what was recorded when the commit was created.
122 Configured via the `.git/info/grafts` file.
125 In git's context, synonym to object name.
128 The top of a branch. It contains a ref to the corresponding
132 A ref pointing to a head. Often, this is abbreviated to "head".
133 Head refs are stored in `$GIT_DIR/refs/heads/`.
136 During the normal execution of several git commands,
137 call-outs are made to optional scripts that allow
138 a developer to add functionality or checking.
139 Typically, the hooks allow for a command to be pre-verified
140 and potentially aborted, and allow for a post-notification
141 after the operation is done.
142 The hook scripts are found in the `$GIT_DIR/hooks/` directory,
143 and are enabled by simply making them executable.
146 A collection of files with stat information, whose contents are
147 stored as objects. The index is a stored version of your working
148 tree. Truth be told, it can also contain a second, and even a third
149 version of a working tree, which are used when merging.
152 The information regarding a particular file, stored in the index.
153 An index entry can be unmerged, if a merge was started, but not
154 yet finished (i.e. if the index contains multiple versions of
158 The default development branch. Whenever you create a git
159 repository, a branch named "master" is created, and becomes
160 the active branch. In most cases, this contains the local
161 development, though that is purely conventional and not required.
164 To merge branches means to try to accumulate the changes since a
165 common ancestor and apply them to the first branch. An automatic
166 merge uses heuristics to accomplish that. Evidently, an automatic
170 The unit of storage in git. It is uniquely identified by
171 the SHA1 of its contents. Consequently, an object can not
175 Stores a set of "objects", and an individual object is identified
176 by its object name. The objects usually live in `$GIT_DIR/objects/`.
179 Synonym for object name.
182 The unique identifier of an object. The hash of the object's contents
183 using the Secure Hash Algorithm 1 and usually represented by the 40
184 character hexadecimal encoding of the hash of the object (possibly
185 followed by a white space).
188 One of the identifiers "commit","tree","tag" and "blob" describing
189 the type of an object.
192 To merge more than two branches. Also denotes an intelligent
196 The default upstream repository. Most projects have at
197 least one upstream project which they track. By default
198 'origin' is used for that purpose. New upstream updates
199 will be fetched into remote tracking branches named
200 origin/name-of-upstream-branch, which you can see using
204 A set of objects which have been compressed into one file (to save
205 space or to transmit them efficiently).
208 The list of identifiers, and other information, of the objects in a
209 pack, to assist in efficiently accessing the contents of a pack.
212 A commit object contains a (possibly empty) list of the logical
213 predecessor(s) in the line of development, i.e. its parents.
216 The term pickaxe refers to an option to the diffcore routines
217 that help select changes that add or delete a given text string.
218 With the --pickaxe-all option, it can be used to view the
219 full changeset that introduced or removed, say, a particular
220 line of text. See gitlink:git-diff[1].
223 Cute name for core git.
226 Cute name for programs and program suites depending on core git,
227 presenting a high level access to core git. Porcelains expose
228 more of a SCM interface than the plumbing.
231 Pulling a branch means to fetch it and merge it.
234 Pushing a branch means to get the branch's head ref from a remote
235 repository, find out if it is an ancestor to the branch's local
236 head ref is a direct, and in that case, putting all objects, which
237 are reachable from the local head ref, and which are missing from
238 the remote repository, into the remote object database, and updating
239 the remote head ref. If the remote head is not an ancestor to the
240 local head, the push fails.
243 All of the ancestors of a given commit are said to be reachable from
244 that commit. More generally, one object is reachable from another if
245 we can reach the one from the other by a chain that follows tags to
246 whatever they tag, commits to their parents or trees, and trees to the
247 trees or blobs that they contain.
250 To clean a branch by starting from the head of the main line of
251 development ("master"), and reapply the (possibly cherry-picked)
252 changes from that branch.
255 A 40-byte hex representation of a SHA1 or a name that denotes
256 a particular object. These may be stored in `$GIT_DIR/refs/`.
259 A refspec is used by fetch and push to describe the mapping
260 between remote ref and local ref. They are combined with
261 a colon in the format <src>:<dst>, preceded by an optional
262 plus sign, +. For example:
263 `git fetch $URL refs/heads/master:refs/heads/origin`
264 means "grab the master branch head from the $URL and store
265 it as my origin branch head".
266 And `git push $URL refs/heads/master:refs/heads/to-upstream`
267 means "publish my master branch head as to-upstream branch
268 at $URL". See also gitlink:git-push[1]
271 A collection of refs together with an object database containing
272 all objects, which are reachable from the refs, possibly accompanied
273 by meta data from one or more porcelains. A repository can
274 share an object database with other repositories.
277 The action of fixing up manually what a failed automatic merge
281 A particular state of files and directories which was stored in
282 the object database. It is referenced by a commit object.
285 To throw away part of the development, i.e. to assign the head to
289 Source code management (tool).
292 Synonym for object name.
295 A shallow repository has an incomplete history some of
296 whose commits have parents cauterized away (in other
297 words, git is told to pretend that these commits do not
298 have the parents, even though they are recorded in the
299 commit object). This is sometimes useful when you are
300 interested only in the recent history of a project even
301 though the real history recorded in the upstream is
302 much larger. A shallow repository is created by giving
303 `--depth` option to gitlink:git-clone[1], and its
304 history can be later deepened with gitlink:git-fetch[1].
307 Symbolic reference: instead of containing the SHA1 id itself, it
308 is of the format 'ref: refs/some/thing' and when referenced, it
309 recursively dereferences to this reference. 'HEAD' is a prime
310 example of a symref. Symbolic references are manipulated with
311 the gitlink:git-symbolic-ref[1] command.
314 A regular git branch that is used by a developer to
315 identify a conceptual line of development. Since branches
316 are very easy and inexpensive, it is often desirable to
317 have several small branches that each contain very well
318 defined concepts or small incremental yet related changes.
321 A regular git branch that is used to follow changes from
322 another repository. A tracking branch should not contain
323 direct modifications or have local commits made to it.
324 A tracking branch can usually be identified as the
325 right-hand-side ref in a Pull: refspec.
328 An object containing a list of file names and modes along with refs
329 to the associated blob and/or tree objects. A tree is equivalent
333 Either a working tree, or a tree object together with the
334 dependent blob and tree objects (i.e. a stored representation
338 A ref pointing to either a commit object, a tree object, or a
339 tag object pointing to a tag or commit or tree object.
342 An object containing a ref pointing to another object, which can
343 contain a message just like a commit object. It can also
344 contain a (PGP) signature, in which case it is called a "signed
348 A ref pointing to a tag or commit object. In contrast to a head,
349 a tag is not changed by a commit. Tags (not tag objects) are
350 stored in `$GIT_DIR/refs/tags/`. A git tag has nothing to do with
351 a Lisp tag (which is called object type in git's context).
352 A tag is most typically used to mark a particular point in the
353 commit ancestry chain.
356 An index which contains unmerged index entries.
359 An object which is not reachable from a branch, tag, or any
363 The set of files and directories currently being worked on,
364 i.e. you can work in your working tree without using git at all.
projects / git / blob