1alternate object database:: 2 Via the alternates mechanism, a repository can inherit part of its 3 object database from another object database, which is called 4 "alternate". 5 6bare repository:: 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. 16 17blob object:: 18 Untyped object, e.g. the contents of a file. 19 20branch:: 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/`. 24 25cache:: 26 Obsolete for: index. 27 28chain:: 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). 32 33changeset:: 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. 37 38checkout:: 39 The action of updating the working tree to a revision which was 40 stored in the object database. 41 42cherry-picking:: 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. 50 51clean:: 52 A working tree is clean, if it corresponds to the revision 53 referenced by the current head. Also see "dirty". 54 55commit:: 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. 59 60commit 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 64 stored revision. 65 66core git:: 67 Fundamental data structures and utilities of git. Exposes only 68 limited source code management tools. 69 70DAG:: 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 74 same object). 75 76dircache:: 77 You are *waaaaay* behind. 78 79dirty:: 80 A working tree is said to be dirty if it contains modifications 81 which have not been committed to the current branch. 82 83directory:: 84 The list you get with "ls" :-) 85 86ent:: 87 Favorite synonym to "tree-ish" by some total geeks. See 88 `http://en.wikipedia.org/wiki/Ent_(Middle-earth)` for an in-depth 89 explanation. Avoid this term, not to confuse people. 90 91fast forward:: 92 A fast-forward is a special type of merge where you have 93 a revision and you are "merging" another branch's changes 94 that happen to be a descendant of what you have. 95 In such these cases, you do not make a new merge commit but 96 instead just update to his revision. This will happen 97 frequently on a tracking branch of a remote repository. 98 99fetch:: 100 Fetching a branch means to get the branch's head ref from a 101 remote repository, to find out which objects are missing from 102 the local object database, and to get them, too. 103 104file system:: 105 Linus Torvalds originally designed git to be a user space file 106 system, i.e. the infrastructure to hold files and directories. 107 That ensured the efficiency and speed of git. 108 109git archive:: 110 Synonym for repository (for arch people). 111 112grafts:: 113 Grafts enables two otherwise different lines of development to be 114 joined together by recording fake ancestry information for commits. 115 This way you can make git pretend the set of parents a commit 116 has is different from what was recorded when the commit was created. 117 Configured via the `.git/info/grafts` file. 118 119hash:: 120 In git's context, synonym to object name. 121 122head:: 123 The top of a branch. It contains a ref to the corresponding 124 commit object. 125 126head ref:: 127 A ref pointing to a head. Often, this is abbreviated to "head". 128 Head refs are stored in `$GIT_DIR/refs/heads/`. 129 130hook:: 131 During the normal execution of several git commands, 132 call-outs are made to optional scripts that allow 133 a developer to add functionality or checking. 134 Typically, the hooks allow for a command to be pre-verified 135 and potentially aborted, and allow for a post-notification 136 after the operation is done. 137 The hook scripts are found in the `$GIT_DIR/hooks/` directory, 138 and are enabled by simply making them executable. 139 140index:: 141 A collection of files with stat information, whose contents are 142 stored as objects. The index is a stored version of your working 143 tree. Truth be told, it can also contain a second, and even a third 144 version of a working tree, which are used when merging. 145 146index entry:: 147 The information regarding a particular file, stored in the index. 148 An index entry can be unmerged, if a merge was started, but not 149 yet finished (i.e. if the index contains multiple versions of 150 that file). 151 152master:: 153 The default development branch. Whenever you create a git 154 repository, a branch named "master" is created, and becomes 155 the active branch. In most cases, this contains the local 156 development, though that is purely conventional and not required. 157 158merge:: 159 To merge branches means to try to accumulate the changes since a 160 common ancestor and apply them to the first branch. An automatic 161 merge uses heuristics to accomplish that. Evidently, an automatic 162 merge can fail. 163 164object:: 165 The unit of storage in git. It is uniquely identified by 166 the SHA1 of its contents. Consequently, an object can not 167 be changed. 168 169object database:: 170 Stores a set of "objects", and an individual object is identified 171 by its object name. The objects usually live in `$GIT_DIR/objects/`. 172 173object identifier:: 174 Synonym for object name. 175 176object name:: 177 The unique identifier of an object. The hash of the object's contents 178 using the Secure Hash Algorithm 1 and usually represented by the 40 179 character hexadecimal encoding of the hash of the object (possibly 180 followed by a white space). 181 182object type:: 183 One of the identifiers "commit","tree","tag" and "blob" describing 184 the type of an object. 185 186octopus:: 187 To merge more than two branches. Also denotes an intelligent 188 predator. 189 190origin:: 191 The default upstream repository. Most projects have at 192 least one upstream project which they track. By default 193 'origin' is used for that purpose. New upstream updates 194 will be fetched into remote tracking branches named 195 origin/name-of-upstream-branch, which you can see using 196 "git branch -r". 197 198pack:: 199 A set of objects which have been compressed into one file (to save 200 space or to transmit them efficiently). 201 202pack index:: 203 The list of identifiers, and other information, of the objects in a 204 pack, to assist in efficiently accessing the contents of a pack. 205 206parent:: 207 A commit object contains a (possibly empty) list of the logical 208 predecessor(s) in the line of development, i.e. its parents. 209 210pickaxe:: 211 The term pickaxe refers to an option to the diffcore routines 212 that help select changes that add or delete a given text string. 213 With the --pickaxe-all option, it can be used to view the 214 full changeset that introduced or removed, say, a particular 215 line of text. See gitlink:git-diff[1]. 216 217plumbing:: 218 Cute name for core git. 219 220porcelain:: 221 Cute name for programs and program suites depending on core git, 222 presenting a high level access to core git. Porcelains expose 223 more of a SCM interface than the plumbing. 224 225pull:: 226 Pulling a branch means to fetch it and merge it. 227 228push:: 229 Pushing a branch means to get the branch's head ref from a remote 230 repository, find out if it is an ancestor to the branch's local 231 head ref is a direct, and in that case, putting all objects, which 232 are reachable from the local head ref, and which are missing from 233 the remote repository, into the remote object database, and updating 234 the remote head ref. If the remote head is not an ancestor to the 235 local head, the push fails. 236 237reachable:: 238 All of the ancestors of a given commit are said to be reachable from 239 that commit. More generally, one object is reachable from another if 240 we can reach the one from the other by a chain that follows tags to 241 whatever they tag, commits to their parents or trees, and trees to the 242 trees or blobs that they contain. 243 244rebase:: 245 To clean a branch by starting from the head of the main line of 246 development ("master"), and reapply the (possibly cherry-picked) 247 changes from that branch. 248 249ref:: 250 A 40-byte hex representation of a SHA1 or a name that denotes 251 a particular object. These may be stored in `$GIT_DIR/refs/`. 252 253refspec:: 254 A refspec is used by fetch and push to describe the mapping 255 between remote ref and local ref. They are combined with 256 a colon in the format <src>:<dst>, preceded by an optional 257 plus sign, +. For example: 258 `git fetch $URL refs/heads/master:refs/heads/origin` 259 means "grab the master branch head from the $URL and store 260 it as my origin branch head". 261 And `git push $URL refs/heads/master:refs/heads/to-upstream` 262 means "publish my master branch head as to-upstream branch 263 at $URL". See also gitlink:git-push[1] 264 265repository:: 266 A collection of refs together with an object database containing 267 all objects, which are reachable from the refs, possibly accompanied 268 by meta data from one or more porcelains. A repository can 269 share an object database with other repositories. 270 271resolve:: 272 The action of fixing up manually what a failed automatic merge 273 left behind. 274 275revision:: 276 A particular state of files and directories which was stored in 277 the object database. It is referenced by a commit object. 278 279rewind:: 280 To throw away part of the development, i.e. to assign the head to 281 an earlier revision. 282 283SCM:: 284 Source code management (tool). 285 286SHA1:: 287 Synonym for object name. 288 289shallow repository:: 290 A shallow repository has an incomplete history some of 291 whose commits have parents cauterized away (in other 292 words, git is told to pretend that these commits do not 293 have the parents, even though they are recorded in the 294 commit object). This is sometimes useful when you are 295 interested only in the recent history of a project even 296 though the real history recorded in the upstream is 297 much larger. A shallow repository is created by giving 298 `--depth` option to gitlink:git-clone[1], and its 299 history can be later deepened with gitlink:git-fetch[1]. 300 301symref:: 302 Symbolic reference: instead of containing the SHA1 id itself, it 303 is of the format 'ref: refs/some/thing' and when referenced, it 304 recursively dereferences to this reference. 'HEAD' is a prime 305 example of a symref. Symbolic references are manipulated with 306 the gitlink:git-symbolic-ref[1] command. 307 308topic branch:: 309 A regular git branch that is used by a developer to 310 identify a conceptual line of development. Since branches 311 are very easy and inexpensive, it is often desirable to 312 have several small branches that each contain very well 313 defined concepts or small incremental yet related changes. 314 315tracking branch:: 316 A regular git branch that is used to follow changes from 317 another repository. A tracking branch should not contain 318 direct modifications or have local commits made to it. 319 A tracking branch can usually be identified as the 320 right-hand-side ref in a Pull: refspec. 321 322tree object:: 323 An object containing a list of file names and modes along with refs 324 to the associated blob and/or tree objects. A tree is equivalent 325 to a directory. 326 327tree:: 328 Either a working tree, or a tree object together with the 329 dependent blob and tree objects (i.e. a stored representation 330 of a working tree). 331 332tree-ish:: 333 A ref pointing to either a commit object, a tree object, or a 334 tag object pointing to a tag or commit or tree object. 335 336tag object:: 337 An object containing a ref pointing to another object, which can 338 contain a message just like a commit object. It can also 339 contain a (PGP) signature, in which case it is called a "signed 340 tag object". 341 342tag:: 343 A ref pointing to a tag or commit object. In contrast to a head, 344 a tag is not changed by a commit. Tags (not tag objects) are 345 stored in `$GIT_DIR/refs/tags/`. A git tag has nothing to do with 346 a Lisp tag (which is called object type in git's context). 347 A tag is most typically used to mark a particular point in the 348 commit ancestry chain. 349 350unmerged index:: 351 An index which contains unmerged index entries. 352 353working tree:: 354 The set of files and directories currently being worked on, 355 i.e. you can work in your working tree without using git at all. 356