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. 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 112hash:: 113 In git's context, synonym to object name. 114 115head:: 116 The top of a branch. It contains a ref to the corresponding 117 commit object. 118 119head ref:: 120 A ref pointing to a head. Often, this is abbreviated to "head". 121 Head refs are stored in `$GIT_DIR/refs/heads/`. 122 123hook:: 124 During the normal execution of several git commands, 125 call-outs are made to optional scripts that allow 126 a developer to add functionality or checking. 127 Typically, the hooks allow for a command to be pre-verified 128 and potentially aborted, and allow for a post-notification 129 after the operation is done. 130 The hook scripts are found in the `$GIT_DIR/hooks/` directory, 131 and are enabled by simply making them executable. 132 133index:: 134 A collection of files with stat information, whose contents are 135 stored as objects. The index is a stored version of your working 136 tree. Truth be told, it can also contain a second, and even a third 137 version of a working tree, which are used when merging. 138 139index entry:: 140 The information regarding a particular file, stored in the index. 141 An index entry can be unmerged, if a merge was started, but not 142 yet finished (i.e. if the index contains multiple versions of 143 that file). 144 145master:: 146 The default development branch. Whenever you create a git 147 repository, a branch named "master" is created, and becomes 148 the active branch. In most cases, this contains the local 149 development, though that is purely conventional and not required. 150 151merge:: 152 To merge branches means to try to accumulate the changes since a 153 common ancestor and apply them to the first branch. An automatic 154 merge uses heuristics to accomplish that. Evidently, an automatic 155 merge can fail. 156 157object:: 158 The unit of storage in git. It is uniquely identified by 159 the SHA1 of its contents. Consequently, an object can not 160 be changed. 161 162object database:: 163 Stores a set of "objects", and an individual object is identified 164 by its object name. The objects usually live in `$GIT_DIR/objects/`. 165 166object identifier:: 167 Synonym for object name. 168 169object name:: 170 The unique identifier of an object. The hash of the object's contents 171 using the Secure Hash Algorithm 1 and usually represented by the 40 172 character hexadecimal encoding of the hash of the object (possibly 173 followed by a white space). 174 175object type: 176 One of the identifiers "commit","tree","tag" and "blob" describing 177 the type of an object. 178 179octopus:: 180 To merge more than two branches. Also denotes an intelligent 181 predator. 182 183origin:: 184 The default upstream tracking branch. Most projects have at 185 least one upstream project which they track. By default 186 'origin' is used for that purpose. New upstream updates 187 will be fetched into this branch; you should never commit 188 to it yourself. 189 190pack:: 191 A set of objects which have been compressed into one file (to save 192 space or to transmit them efficiently). 193 194pack index:: 195 The list of identifiers, and other information, of the objects in a 196 pack, to assist in efficiently accessing the contents of a pack. 197 198parent:: 199 A commit object contains a (possibly empty) list of the logical 200 predecessor(s) in the line of development, i.e. its parents. 201 202pickaxe:: 203 The term pickaxe refers to an option to the diffcore routines 204 that help select changes that add or delete a given text string. 205 With the --pickaxe-all option, it can be used to view the 206 full changeset that introduced or removed, say, a particular 207 line of text. See gitlink:git-diff[1]. 208 209plumbing:: 210 Cute name for core git. 211 212porcelain:: 213 Cute name for programs and program suites depending on core git, 214 presenting a high level access to core git. Porcelains expose 215 more of a SCM interface than the plumbing. 216 217pull:: 218 Pulling a branch means to fetch it and merge it. 219 220push:: 221 Pushing a branch means to get the branch's head ref from a remote 222 repository, find out if it is an ancestor to the branch's local 223 head ref is a direct, and in that case, putting all objects, which 224 are reachable from the local head ref, and which are missing from 225 the remote repository, into the remote object database, and updating 226 the remote head ref. If the remote head is not an ancestor to the 227 local head, the push fails. 228 229reachable:: 230 An object is reachable from a ref/commit/tree/tag, if there is a 231 chain leading from the latter to the former. 232 233rebase:: 234 To clean a branch by starting from the head of the main line of 235 development ("master"), and reapply the (possibly cherry-picked) 236 changes from that branch. 237 238ref:: 239 A 40-byte hex representation of a SHA1 or a name that denotes 240 a particular object. These may be stored in `$GIT_DIR/refs/`. 241 242refspec:: 243 A refspec is used by fetch and push to describe the mapping 244 between remote ref and local ref. They are combined with 245 a colon in the format <src>:<dst>, preceded by an optional 246 plus sign, +. For example: 247 `git fetch $URL refs/heads/master:refs/heads/origin` 248 means "grab the master branch head from the $URL and store 249 it as my origin branch head". 250 And `git push $URL refs/heads/master:refs/heads/to-upstream` 251 means "publish my master branch head as to-upstream master head 252 at $URL". See also gitlink:git-push[1] 253 254repository:: 255 A collection of refs together with an object database containing 256 all objects, which are reachable from the refs, possibly accompanied 257 by meta data from one or more porcelains. A repository can 258 share an object database with other repositories. 259 260resolve:: 261 The action of fixing up manually what a failed automatic merge 262 left behind. 263 264revision:: 265 A particular state of files and directories which was stored in 266 the object database. It is referenced by a commit object. 267 268rewind:: 269 To throw away part of the development, i.e. to assign the head to 270 an earlier revision. 271 272SCM:: 273 Source code management (tool). 274 275SHA1:: 276 Synonym for object name. 277 278topic branch:: 279 A regular git branch that is used by a developer to 280 identify a conceptual line of development. Since branches 281 are very easy and inexpensive, it is often desirable to 282 have several small branches that each contain very well 283 defined concepts or small incremental yet related changes. 284 285tracking branch:: 286 A regular git branch that is used to follow changes from 287 another repository. A tracking branch should not contain 288 direct modifications or have local commits made to it. 289 A tracking branch can usually be identified as the 290 right-hand-side ref in a Pull: refspec. 291 292tree object:: 293 An object containing a list of file names and modes along with refs 294 to the associated blob and/or tree objects. A tree is equivalent 295 to a directory. 296 297tree:: 298 Either a working tree, or a tree object together with the 299 dependent blob and tree objects (i.e. a stored representation 300 of a working tree). 301 302tree-ish:: 303 A ref pointing to either a commit object, a tree object, or a 304 tag object pointing to a tag or commit or tree object. 305 306tag object:: 307 An object containing a ref pointing to another object, which can 308 contain a message just like a commit object. It can also 309 contain a (PGP) signature, in which case it is called a "signed 310 tag object". 311 312tag:: 313 A ref pointing to a tag or commit object. In contrast to a head, 314 a tag is not changed by a commit. Tags (not tag objects) are 315 stored in `$GIT_DIR/refs/tags/`. A git tag has nothing to do with 316 a Lisp tag (which is called object type in git's context). 317 A tag is most typically used to mark a particular point in the 318 commit ancestry chain. 319 320unmerged index: 321 An index which contains unmerged index entries. 322 323working tree:: 324 The set of files and directories currently being worked on, 325 i.e. you can work in your working tree without using git at all. 326