1[[def_alternate_object_database]]alternate object database:: 2 Via the alternates mechanism, a <<def_repository,repository>> 3 can inherit part of its <<def_object_database,object database>> 4 from another object database, which is called "alternate". 5 6[[def_bare_repository]]bare repository:: 7 A bare repository is normally an appropriately 8 named <<def_directory,directory>> with a `.git` suffix that does not 9 have a locally checked-out copy of any of the files under 10 revision control. That is, all of the Git 11 administrative and control files that would normally be present in the 12 hidden `.git` sub-directory are directly present in the 13 `repository.git` directory instead, 14 and no other files are present and checked out. Usually publishers of 15 public repositories make bare repositories available. 16 17[[def_blob_object]]blob object:: 18 Untyped <<def_object,object>>, e.g. the contents of a file. 19 20[[def_branch]]branch:: 21 A "branch" is an active line of development. The most recent 22 <<def_commit,commit>> on a branch is referred to as the tip of 23 that branch. The tip of the branch is referenced by a branch 24 <<def_head,head>>, which moves forward as additional development 25 is done on the branch. A single Git 26 <<def_repository,repository>> can track an arbitrary number of 27 branches, but your <<def_working_tree,working tree>> is 28 associated with just one of them (the "current" or "checked out" 29 branch), and <<def_HEAD,HEAD>> points to that branch. 30 31[[def_cache]]cache:: 32 Obsolete for: <<def_index,index>>. 33 34[[def_chain]]chain:: 35 A list of objects, where each <<def_object,object>> in the list contains 36 a reference to its successor (for example, the successor of a 37 <<def_commit,commit>> could be one of its <<def_parent,parents>>). 38 39[[def_changeset]]changeset:: 40 BitKeeper/cvsps speak for "<<def_commit,commit>>". Since Git does not 41 store changes, but states, it really does not make sense to use the term 42 "changesets" with Git. 43 44[[def_checkout]]checkout:: 45 The action of updating all or part of the 46 <<def_working_tree,working tree>> with a <<def_tree_object,tree object>> 47 or <<def_blob_object,blob>> from the 48 <<def_object_database,object database>>, and updating the 49 <<def_index,index>> and <<def_HEAD,HEAD>> if the whole working tree has 50 been pointed at a new <<def_branch,branch>>. 51 52[[def_cherry-picking]]cherry-picking:: 53 In <<def_SCM,SCM>> jargon, "cherry pick" means to choose a subset of 54 changes out of a series of changes (typically commits) and record them 55 as a new series of changes on top of a different codebase. In Git, this is 56 performed by the "git cherry-pick" command to extract the change introduced 57 by an existing <<def_commit,commit>> and to record it based on the tip 58 of the current <<def_branch,branch>> as a new commit. 59 60[[def_clean]]clean:: 61 A <<def_working_tree,working tree>> is clean, if it 62 corresponds to the <<def_revision,revision>> referenced by the current 63 <<def_head,head>>. Also see "<<def_dirty,dirty>>". 64 65[[def_commit]]commit:: 66 As a noun: A single point in the 67 Git history; the entire history of a project is represented as a 68 set of interrelated commits. The word "commit" is often 69 used by Git in the same places other revision control systems 70 use the words "revision" or "version". Also used as a short 71 hand for <<def_commit_object,commit object>>. 72+ 73As a verb: The action of storing a new snapshot of the project's 74state in the Git history, by creating a new commit representing the current 75state of the <<def_index,index>> and advancing <<def_HEAD,HEAD>> 76to point at the new commit. 77 78[[def_commit_object]]commit object:: 79 An <<def_object,object>> which contains the information about a 80 particular <<def_revision,revision>>, such as <<def_parent,parents>>, committer, 81 author, date and the <<def_tree_object,tree object>> which corresponds 82 to the top <<def_directory,directory>> of the stored 83 revision. 84 85[[def_core_git]]core Git:: 86 Fundamental data structures and utilities of Git. Exposes only limited 87 source code management tools. 88 89[[def_DAG]]DAG:: 90 Directed acyclic graph. The <<def_commit_object,commit objects>> form a 91 directed acyclic graph, because they have parents (directed), and the 92 graph of commit objects is acyclic (there is no <<def_chain,chain>> 93 which begins and ends with the same <<def_object,object>>). 94 95[[def_dangling_object]]dangling object:: 96 An <<def_unreachable_object,unreachable object>> which is not 97 <<def_reachable,reachable>> even from other unreachable objects; a 98 dangling object has no references to it from any 99 reference or <<def_object,object>> in the <<def_repository,repository>>. 100 101[[def_detached_HEAD]]detached HEAD:: 102 Normally the <<def_HEAD,HEAD>> stores the name of a 103 <<def_branch,branch>>. However, Git also allows you to <<def_checkout,check out>> 104 an arbitrary <<def_commit,commit>> that isn't necessarily the tip of any 105 particular branch. In this case HEAD is said to be "detached". 106 107[[def_dircache]]dircache:: 108 You are *waaaaay* behind. See <<def_index,index>>. 109 110[[def_directory]]directory:: 111 The list you get with "ls" :-) 112 113[[def_dirty]]dirty:: 114 A <<def_working_tree,working tree>> is said to be "dirty" if 115 it contains modifications which have not been <<def_commit,committed>> to the current 116 <<def_branch,branch>>. 117 118[[def_ent]]ent:: 119 Favorite synonym to "<<def_tree-ish,tree-ish>>" by some total geeks. See 120 http://en.wikipedia.org/wiki/Ent_(Middle-earth) for an in-depth 121 explanation. Avoid this term, not to confuse people. 122 123[[def_evil_merge]]evil merge:: 124 An evil merge is a <<def_merge,merge>> that introduces changes that 125 do not appear in any <<def_parent,parent>>. 126 127[[def_fast_forward]]fast-forward:: 128 A fast-forward is a special type of <<def_merge,merge>> where you have a 129 <<def_revision,revision>> and you are "merging" another 130 <<def_branch,branch>>'s changes that happen to be a descendant of what 131 you have. In such these cases, you do not make a new <<def_merge,merge>> 132 <<def_commit,commit>> but instead just update to his 133 revision. This will happen frequently on a 134 <<def_remote_tracking_branch,remote-tracking branch>> of a remote 135 <<def_repository,repository>>. 136 137[[def_fetch]]fetch:: 138 Fetching a <<def_branch,branch>> means to get the 139 branch's <<def_head_ref,head ref>> from a remote 140 <<def_repository,repository>>, to find out which objects are 141 missing from the local <<def_object_database,object database>>, 142 and to get them, too. See also linkgit:git-fetch[1]. 143 144[[def_file_system]]file system:: 145 Linus Torvalds originally designed Git to be a user space file system, 146 i.e. the infrastructure to hold files and directories. That ensured the 147 efficiency and speed of Git. 148 149[[def_git_archive]]Git archive:: 150 Synonym for <<def_repository,repository>> (for arch people). 151 152[[def_gitfile]]gitfile:: 153 A plain file `.git` at the root of a working tree that 154 points at the directory that is the real repository. 155 156[[def_grafts]]grafts:: 157 Grafts enables two otherwise different lines of development to be joined 158 together by recording fake ancestry information for commits. This way 159 you can make Git pretend the set of <<def_parent,parents>> a <<def_commit,commit>> has 160 is different from what was recorded when the commit was 161 created. Configured via the `.git/info/grafts` file. 162 163[[def_hash]]hash:: 164 In Git's context, synonym to <<def_object_name,object name>>. 165 166[[def_head]]head:: 167 A <<def_ref,named reference>> to the <<def_commit,commit>> at the tip of a 168 <<def_branch,branch>>. Heads are stored in a file in 169 `$GIT_DIR/refs/heads/` directory, except when using packed refs. (See 170 linkgit:git-pack-refs[1].) 171 172[[def_HEAD]]HEAD:: 173 The current <<def_branch,branch>>. In more detail: Your <<def_working_tree, 174 working tree>> is normally derived from the state of the tree 175 referred to by HEAD. HEAD is a reference to one of the 176 <<def_head,heads>> in your repository, except when using a 177 <<def_detached_HEAD,detached HEAD>>, in which case it directly 178 references an arbitrary commit. 179 180[[def_head_ref]]head ref:: 181 A synonym for <<def_head,head>>. 182 183[[def_hook]]hook:: 184 During the normal execution of several Git commands, call-outs are made 185 to optional scripts that allow a developer to add functionality or 186 checking. Typically, the hooks allow for a command to be pre-verified 187 and potentially aborted, and allow for a post-notification after the 188 operation is done. The hook scripts are found in the 189 `$GIT_DIR/hooks/` directory, and are enabled by simply 190 removing the `.sample` suffix from the filename. In earlier versions 191 of Git you had to make them executable. 192 193[[def_index]]index:: 194 A collection of files with stat information, whose contents are stored 195 as objects. The index is a stored version of your 196 <<def_working_tree,working tree>>. Truth be told, it can also contain a second, and even 197 a third version of a working tree, which are used 198 when <<def_merge,merging>>. 199 200[[def_index_entry]]index entry:: 201 The information regarding a particular file, stored in the 202 <<def_index,index>>. An index entry can be unmerged, if a 203 <<def_merge,merge>> was started, but not yet finished (i.e. if 204 the index contains multiple versions of that file). 205 206[[def_master]]master:: 207 The default development <<def_branch,branch>>. Whenever you 208 create a Git <<def_repository,repository>>, a branch named 209 "master" is created, and becomes the active branch. In most 210 cases, this contains the local development, though that is 211 purely by convention and is not required. 212 213[[def_merge]]merge:: 214 As a verb: To bring the contents of another 215 <<def_branch,branch>> (possibly from an external 216 <<def_repository,repository>>) into the current branch. In the 217 case where the merged-in branch is from a different repository, 218 this is done by first <<def_fetch,fetching>> the remote branch 219 and then merging the result into the current branch. This 220 combination of fetch and merge operations is called a 221 <<def_pull,pull>>. Merging is performed by an automatic process 222 that identifies changes made since the branches diverged, and 223 then applies all those changes together. In cases where changes 224 conflict, manual intervention may be required to complete the 225 merge. 226+ 227As a noun: unless it is a <<def_fast_forward,fast-forward>>, a 228successful merge results in the creation of a new <<def_commit,commit>> 229representing the result of the merge, and having as 230<<def_parent,parents>> the tips of the merged <<def_branch,branches>>. 231This commit is referred to as a "merge commit", or sometimes just a 232"merge". 233 234[[def_object]]object:: 235 The unit of storage in Git. It is uniquely identified by the 236 <<def_SHA1,SHA1>> of its contents. Consequently, an 237 object can not be changed. 238 239[[def_object_database]]object database:: 240 Stores a set of "objects", and an individual <<def_object,object>> is 241 identified by its <<def_object_name,object name>>. The objects usually 242 live in `$GIT_DIR/objects/`. 243 244[[def_object_identifier]]object identifier:: 245 Synonym for <<def_object_name,object name>>. 246 247[[def_object_name]]object name:: 248 The unique identifier of an <<def_object,object>>. The <<def_hash,hash>> 249 of the object's contents using the Secure Hash Algorithm 250 1 and usually represented by the 40 character hexadecimal encoding of 251 the <<def_hash,hash>> of the object. 252 253[[def_object_type]]object type:: 254 One of the identifiers "<<def_commit_object,commit>>", 255 "<<def_tree_object,tree>>", "<<def_tag_object,tag>>" or 256 "<<def_blob_object,blob>>" describing the type of an 257 <<def_object,object>>. 258 259[[def_octopus]]octopus:: 260 To <<def_merge,merge>> more than two <<def_branch,branches>>. Also denotes an 261 intelligent predator. 262 263[[def_origin]]origin:: 264 The default upstream <<def_repository,repository>>. Most projects have 265 at least one upstream project which they track. By default 266 'origin' is used for that purpose. New upstream updates 267 will be fetched into remote <<def_remote_tracking_branch,remote-tracking branches>> named 268 origin/name-of-upstream-branch, which you can see using 269 `git branch -r`. 270 271[[def_pack]]pack:: 272 A set of objects which have been compressed into one file (to save space 273 or to transmit them efficiently). 274 275[[def_pack_index]]pack index:: 276 The list of identifiers, and other information, of the objects in a 277 <<def_pack,pack>>, to assist in efficiently accessing the contents of a 278 pack. 279 280[[def_pathspec]]pathspec:: 281 Pattern used to specify paths. 282+ 283Pathspecs are used on the command line of "git ls-files", "git 284ls-tree", "git add", "git grep", "git diff", "git checkout", 285and many other commands to 286limit the scope of operations to some subset of the tree or 287worktree. See the documentation of each command for whether 288paths are relative to the current directory or toplevel. The 289pathspec syntax is as follows: 290 291* any path matches itself 292* the pathspec up to the last slash represents a 293 directory prefix. The scope of that pathspec is 294 limited to that subtree. 295* the rest of the pathspec is a pattern for the remainder 296 of the pathname. Paths relative to the directory 297 prefix will be matched against that pattern using fnmatch(3); 298 in particular, '*' and '?' _can_ match directory separators. 299+ 300For example, Documentation/*.jpg will match all .jpg files 301in the Documentation subtree, 302including Documentation/chapter_1/figure_1.jpg. 303 304+ 305A pathspec that begins with a colon `:` has special meaning. In the 306short form, the leading colon `:` is followed by zero or more "magic 307signature" letters (which optionally is terminated by another colon `:`), 308and the remainder is the pattern to match against the path. The optional 309colon that terminates the "magic signature" can be omitted if the pattern 310begins with a character that cannot be a "magic signature" and is not a 311colon. 312+ 313In the long form, the leading colon `:` is followed by a open 314parenthesis `(`, a comma-separated list of zero or more "magic words", 315and a close parentheses `)`, and the remainder is the pattern to match 316against the path. 317+ 318The "magic signature" consists of an ASCII symbol that is not 319alphanumeric. 320+ 321-- 322top `/`;; 323 The magic word `top` (mnemonic: `/`) makes the pattern match 324 from the root of the working tree, even when you are running 325 the command from inside a subdirectory. 326-- 327+ 328Currently only the slash `/` is recognized as the "magic signature", 329but it is envisioned that we will support more types of magic in later 330versions of Git. 331+ 332A pathspec with only a colon means "there is no pathspec". This form 333should not be combined with other pathspec. 334 335[[def_parent]]parent:: 336 A <<def_commit_object,commit object>> contains a (possibly empty) list 337 of the logical predecessor(s) in the line of development, i.e. its 338 parents. 339 340[[def_pickaxe]]pickaxe:: 341 The term <<def_pickaxe,pickaxe>> refers to an option to the diffcore 342 routines that help select changes that add or delete a given text 343 string. With the `--pickaxe-all` option, it can be used to view the full 344 <<def_changeset,changeset>> that introduced or removed, say, a 345 particular line of text. See linkgit:git-diff[1]. 346 347[[def_plumbing]]plumbing:: 348 Cute name for <<def_core_git,core Git>>. 349 350[[def_porcelain]]porcelain:: 351 Cute name for programs and program suites depending on 352 <<def_core_git,core Git>>, presenting a high level access to 353 core Git. Porcelains expose more of a <<def_SCM,SCM>> 354 interface than the <<def_plumbing,plumbing>>. 355 356[[def_pull]]pull:: 357 Pulling a <<def_branch,branch>> means to <<def_fetch,fetch>> it and 358 <<def_merge,merge>> it. See also linkgit:git-pull[1]. 359 360[[def_push]]push:: 361 Pushing a <<def_branch,branch>> means to get the branch's 362 <<def_head_ref,head ref>> from a remote <<def_repository,repository>>, 363 find out if it is a direct ancestor to the branch's local 364 head ref, and in that case, putting all 365 objects, which are <<def_reachable,reachable>> from the local 366 head ref, and which are missing from the remote 367 repository, into the remote 368 <<def_object_database,object database>>, and updating the remote 369 head ref. If the remote <<def_head,head>> is not an 370 ancestor to the local head, the push fails. 371 372[[def_reachable]]reachable:: 373 All of the ancestors of a given <<def_commit,commit>> are said to be 374 "reachable" from that commit. More 375 generally, one <<def_object,object>> is reachable from 376 another if we can reach the one from the other by a <<def_chain,chain>> 377 that follows <<def_tag,tags>> to whatever they tag, 378 <<def_commit_object,commits>> to their parents or trees, and 379 <<def_tree_object,trees>> to the trees or <<def_blob_object,blobs>> 380 that they contain. 381 382[[def_rebase]]rebase:: 383 To reapply a series of changes from a <<def_branch,branch>> to a 384 different base, and reset the <<def_head,head>> of that branch 385 to the result. 386 387[[def_ref]]ref:: 388 A 40-byte hex representation of a <<def_SHA1,SHA1>> or a name that 389 denotes a particular <<def_object,object>>. They may be stored in 390 a file under `$GIT_DIR/refs/` directory, or 391 in the `$GIT_DIR/packed-refs` file. 392 393[[def_reflog]]reflog:: 394 A reflog shows the local "history" of a ref. In other words, 395 it can tell you what the 3rd last revision in _this_ repository 396 was, and what was the current state in _this_ repository, 397 yesterday 9:14pm. See linkgit:git-reflog[1] for details. 398 399[[def_refspec]]refspec:: 400 A "refspec" is used by <<def_fetch,fetch>> and 401 <<def_push,push>> to describe the mapping between remote 402 <<def_ref,ref>> and local ref. They are combined with a colon in 403 the format <src>:<dst>, preceded by an optional plus sign, +. 404 For example: `git fetch $URL 405 refs/heads/master:refs/heads/origin` means "grab the master 406 <<def_branch,branch>> <<def_head,head>> from the $URL and store 407 it as my origin branch head". And `git push 408 $URL refs/heads/master:refs/heads/to-upstream` means "publish my 409 master branch head as to-upstream branch at $URL". See also 410 linkgit:git-push[1]. 411 412[[def_remote_tracking_branch]]remote-tracking branch:: 413 A regular Git <<def_branch,branch>> that is used to follow changes from 414 another <<def_repository,repository>>. A remote-tracking 415 branch should not contain direct modifications or have local commits 416 made to it. A remote-tracking branch can usually be 417 identified as the right-hand-side <<def_ref,ref>> in a Pull: 418 <<def_refspec,refspec>>. 419 420[[def_repository]]repository:: 421 A collection of <<def_ref,refs>> together with an 422 <<def_object_database,object database>> containing all objects 423 which are <<def_reachable,reachable>> from the refs, possibly 424 accompanied by meta data from one or more <<def_porcelain,porcelains>>. A 425 repository can share an object database with other repositories 426 via <<def_alternate_object_database,alternates mechanism>>. 427 428[[def_resolve]]resolve:: 429 The action of fixing up manually what a failed automatic 430 <<def_merge,merge>> left behind. 431 432[[def_revision]]revision:: 433 A particular state of files and directories which was stored in the 434 <<def_object_database,object database>>. It is referenced by a 435 <<def_commit_object,commit object>>. 436 437[[def_rewind]]rewind:: 438 To throw away part of the development, i.e. to assign the 439 <<def_head,head>> to an earlier <<def_revision,revision>>. 440 441[[def_SCM]]SCM:: 442 Source code management (tool). 443 444[[def_SHA1]]SHA1:: 445 Synonym for <<def_object_name,object name>>. 446 447[[def_shallow_repository]]shallow repository:: 448 A shallow <<def_repository,repository>> has an incomplete 449 history some of whose <<def_commit,commits>> have <<def_parent,parents>> cauterized away (in other 450 words, Git is told to pretend that these commits do not have the 451 parents, even though they are recorded in the <<def_commit_object,commit 452 object>>). This is sometimes useful when you are interested only in the 453 recent history of a project even though the real history recorded in the 454 upstream is much larger. A shallow repository 455 is created by giving the `--depth` option to linkgit:git-clone[1], and 456 its history can be later deepened with linkgit:git-fetch[1]. 457 458[[def_symref]]symref:: 459 Symbolic reference: instead of containing the <<def_SHA1,SHA1>> 460 id itself, it is of the format 'ref: refs/some/thing' and when 461 referenced, it recursively dereferences to this reference. 462 '<<def_HEAD,HEAD>>' is a prime example of a symref. Symbolic 463 references are manipulated with the linkgit:git-symbolic-ref[1] 464 command. 465 466[[def_tag]]tag:: 467 A <<def_ref,ref>> under `refs/tags/` namespace that points to an 468 object of an arbitrary type (typically a tag points to either a 469 <<def_tag_object,tag>> or a <<def_commit_object,commit object>>). 470 In contrast to a <<def_head,head>>, a tag is not updated by 471 the `commit` command. A Git tag has nothing to do with a Lisp 472 tag (which would be called an <<def_object_type,object type>> 473 in Git's context). A tag is most typically used to mark a particular 474 point in the commit ancestry <<def_chain,chain>>. 475 476[[def_tag_object]]tag object:: 477 An <<def_object,object>> containing a <<def_ref,ref>> pointing to 478 another object, which can contain a message just like a 479 <<def_commit_object,commit object>>. It can also contain a (PGP) 480 signature, in which case it is called a "signed tag object". 481 482[[def_topic_branch]]topic branch:: 483 A regular Git <<def_branch,branch>> that is used by a developer to 484 identify a conceptual line of development. Since branches are very easy 485 and inexpensive, it is often desirable to have several small branches 486 that each contain very well defined concepts or small incremental yet 487 related changes. 488 489[[def_tree]]tree:: 490 Either a <<def_working_tree,working tree>>, or a <<def_tree_object,tree 491 object>> together with the dependent <<def_blob_object,blob>> and tree objects 492 (i.e. a stored representation of a working tree). 493 494[[def_tree_object]]tree object:: 495 An <<def_object,object>> containing a list of file names and modes along 496 with refs to the associated blob and/or tree objects. A 497 <<def_tree,tree>> is equivalent to a <<def_directory,directory>>. 498 499[[def_tree-ish]]tree-ish:: 500 A <<def_ref,ref>> pointing to either a <<def_commit_object,commit 501 object>>, a <<def_tree_object,tree object>>, or a <<def_tag_object,tag 502 object>> pointing to a tag or commit or tree object. 503 504[[def_unmerged_index]]unmerged index:: 505 An <<def_index,index>> which contains unmerged 506 <<def_index_entry,index entries>>. 507 508[[def_unreachable_object]]unreachable object:: 509 An <<def_object,object>> which is not <<def_reachable,reachable>> from a 510 <<def_branch,branch>>, <<def_tag,tag>>, or any other reference. 511 512[[def_upstream_branch]]upstream branch:: 513 The default <<def_branch,branch>> that is merged into the branch in 514 question (or the branch in question is rebased onto). It is configured 515 via branch.<name>.remote and branch.<name>.merge. If the upstream branch 516 of 'A' is 'origin/B' sometimes we say "'A' is tracking 'origin/B'". 517 518[[def_working_tree]]working tree:: 519 The tree of actual checked out files. The working tree normally 520 contains the contents of the <<def_HEAD,HEAD>> commit's tree, 521 plus any local changes that you have made but not yet committed.