[PATCH] Add git-var a tool for reading interesting git variables.
[git.git] / Documentation / git.txt
1 git(7)
2 ======
3 May 2005
4
5 NAME
6 ----
7 git - the stupid content tracker
8
9
10 SYNOPSIS
11 --------
12 'git-<command>' <args>
13
14 DESCRIPTION
15 -----------
16
17 This is reference information for the core git commands.
18
19 The Discussion section below contains much useful definition and
20 clarification info - read that first.  And of the commands, I suggest
21 reading link:git-update-cache.html[git-update-cache] and
22 link:git-read-tree.html[git-read-tree] first - I wish I had!
23
24 David Greaves <david@dgreaves.com>
25 08/05/05
26
27 Updated by Junio C Hamano <junkio@cox.net> on 2005-05-05 to
28 reflect recent changes.
29
30 Commands Overview
31 -----------------
32 The git commands can helpfully be split into those that manipulate
33 the repository, the cache and the working fileset, those that
34 interrogate and compare them, and those that moves objects and
35 references between repositories.
36
37 There are also some ancilliary programs that can be viewed as useful
38 aids for using the core commands but which are unlikely to be used by
39 SCMs layered over git.
40
41 Manipulation commands
42 ~~~~~~~~~~~~~~~~~~~~~
43 link:git-checkout-cache.html[git-checkout-cache]::
44         Copy files from the cache to the working directory
45
46 link:git-commit-tree.html[git-commit-tree]::
47         Creates a new commit object
48
49 link:git-init-db.html[git-init-db]::
50         Creates an empty git object database
51
52 link:git-merge-base.html[git-merge-base]::
53         Finds as good a common ancestor as possible for a merge
54
55 link:git-mktag.html[git-mktag]::
56         Creates a tag object
57
58 link:git-read-tree.html[git-read-tree]::
59         Reads tree information into the directory cache
60
61 link:git-update-cache.html[git-update-cache]::
62         Modifies the index or directory cache
63
64 link:git-hash-object.html[git-hash-object]::
65         Computes the object ID from a file.
66
67 link:git-write-tree.html[git-write-tree]::
68         Creates a tree from the current cache
69
70 Interrogation commands
71 ~~~~~~~~~~~~~~~~~~~~~~
72 link:git-cat-file.html[git-cat-file]::
73         Provide content or type information for repository objects
74
75 link:git-check-files.html[git-check-files]::
76         Verify a list of files are up-to-date
77
78 link:git-diff-cache.html[git-diff-cache]::
79         Compares content and mode of blobs between the cache and repository
80
81 link:git-diff-files.html[git-diff-files]::
82         Compares files in the working tree and the cache
83
84 link:git-diff-tree.html[git-diff-tree]::
85         Compares the content and mode of blobs found via two tree objects
86
87 link:git-export.html[git-export]::
88         Exports each commit and a diff against each of its parents
89
90 link:git-fsck-cache.html[git-fsck-cache]::
91         Verifies the connectivity and validity of the objects in the database
92
93 link:git-ls-files.html[git-ls-files]::
94         Information about files in the cache/working directory
95
96 link:git-ls-tree.html[git-ls-tree]::
97         Displays a tree object in human readable form
98
99 link:git-merge-cache.html[git-merge-cache]::
100         Runs a merge for files needing merging
101
102 link:git-rev-list.html[git-rev-list]::
103         Lists commit objects in reverse chronological order
104
105 link:git-rev-tree.html[git-rev-tree]::
106         Provides the revision tree for one or more commits
107
108 link:git-tar-tree.html[git-tar-tree]::
109         Creates a tar archive of the files in the named tree
110
111 link:git-unpack-file.html[git-unpack-file]::
112         Creates a temporary file with a blob's contents
113
114 link:git-var.html[git-var]::
115         Displays a git logical variable
116
117 link:git-verify-pack.html[git-verify-pack]::
118         Validates packed GIT archive files
119
120 The interrogate commands may create files - and you can force them to
121 touch the working file set - but in general they don't
122
123
124 link:git-clone-script.html[git-clone-script]::
125         Clones a repository into the current repository (user interface)
126
127 link:git-clone-pack.html[git-clone-pack]::
128         Clones a repository into the current repository (engine
129         for ssh and local transport)
130
131 link:git-pull-script.html[git-pull-script]::
132         Pull from a repote repository via various protocols
133         (user interface).
134
135 link:git-http-pull.html[git-http-pull]::
136         Downloads a remote GIT repository via HTTP
137
138 link:git-local-pull.html[git-local-pull]::
139         Duplicates another GIT repository on a local system
140
141 link:git-ssh-pull.html[git-ssh-pull]::
142         Pulls from a remote repository over ssh connection
143
144 link:git-send-pack.html[git-send-pack]::
145         Pushes to a remote repository, intelligently.
146
147 link:git-receive-pack.html[git-receive-pack]::
148         Invoked by 'git-send-pack' to receive what is pushed to it.
149
150 link:git-clone-pack.html[git-clone-pack]::
151         Clones from a remote repository.
152
153 link:git-fetch-pack.html[git-fetch-pack]::
154         Updates from a remote repository.
155
156 link:git-upload-pack.html[git-upload-pack]::
157         Invoked by 'git-clone-pack' and 'git-fetch-pack' to push
158         what are asked for.
159
160
161 Ancilliary Commands
162 -------------------
163 Manipulators:
164
165 link:git-apply-patch-script.html[git-apply-patch-script]::
166         Sample script to apply the diffs from git-diff-*
167
168 link:git-convert-cache.html[git-convert-cache]::
169         Converts old-style GIT repository
170
171 link:git-merge-one-file-script.html[git-merge-one-file-script]::
172         The standard helper program to use with "git-merge-cache"
173
174 link:git-prune-script.html[git-prune-script]::
175         Prunes all unreachable objects from the object database
176
177 link:git-resolve-script.html[git-resolve-script]::
178         Script used to merge two trees
179
180 link:git-tag-script.html[git-tag-script]::
181         An example script to create a tag object signed with GPG
182
183
184 Interogators:
185
186 link:git-diff-helper.html[git-diff-helper]::
187         Generates patch format output for git-diff-*
188
189 link:git-ssh-push.html[git-ssh-push]::
190         Helper "server-side" program used by git-ssh-pull
191
192
193
194 Identifier Terminology
195 ----------------------
196 <object>::
197         Indicates the sha1 identifier for any type of object
198
199 <blob>::
200         Indicates a blob object sha1 identifier
201
202 <tree>::
203         Indicates a tree object sha1 identifier
204
205 <commit>::
206         Indicates a commit object sha1 identifier
207
208 <tree-ish>::
209         Indicates a tree, commit or tag object sha1 identifier.  A
210         command that takes a <tree-ish> argument ultimately wants to
211         operate on a <tree> object but automatically dereferences
212         <commit> and <tag> objects that point at a <tree>.
213
214 <type>::
215         Indicates that an object type is required.
216         Currently one of: blob/tree/commit/tag
217
218 <file>::
219         Indicates a filename - always relative to the root of
220         the tree structure GIT_INDEX_FILE describes.
221
222 Symbolic Identifiers
223 --------------------
224 Any git comand accepting any <object> can also use the following
225 symbolic notation:
226
227 HEAD::
228         indicates the head of the repository (ie the contents of
229         `$GIT_DIR/HEAD`)
230 <tag>::
231         a valid tag 'name'+
232         (ie the contents of `$GIT_DIR/refs/tags/<tag>`)
233 <head>::
234         a valid head 'name'+
235         (ie the contents of `$GIT_DIR/refs/heads/<head>`)
236 <snap>::
237         a valid snapshot 'name'+
238         (ie the contents of `$GIT_DIR/refs/snap/<snap>`)
239
240
241 File/Directory Structure
242 ------------------------
243 The git-core manipulates the following areas in the directory:
244
245  .git/         The base (overridden with $GIT_DIR)
246    objects/    The object base (overridden with $GIT_OBJECT_DIRECTORY)
247      ??/       'First 2 chars of object' directories.
248      pack/     Packed archives.
249
250    refs/       Directories containing symbolic names for objects
251                (each file contains the hex SHA1 + newline)
252      heads/    Commits which are heads of various sorts
253      tags/     Tags, by the tag name (or some local renaming of it)
254      */        Any other subdirectory of refs/ can be used to store
255                files similar to what are under refs/heads/.
256    HEAD        Symlink to refs/heads/<current-branch-name>
257
258 Higher level SCMs may provide and manage additional information in the
259 GIT_DIR.
260
261 Terminology
262 -----------
263 Each line contains terms which you may see used interchangeably
264
265  object database, .git directory
266  directory cache, index
267  id, sha1, sha1-id, sha1 hash
268  type, tag
269
270
271 Environment Variables
272 ---------------------
273 Various git commands use the following environment variables:
274
275 The git Repository
276 ~~~~~~~~~~~~~~~~~~
277 These environment variables apply to 'all' core git commands. Nb: it
278 is worth noting that they may be used/overridden by SCMS sitting above
279 git so take care if using Cogito etc
280
281 'GIT_INDEX_FILE'::
282         This environment allows the specification of an alternate
283         cache/index file. If not specified, the default of
284         `$GIT_DIR/index` is used.
285
286 'GIT_OBJECT_DIRECTORY'::
287         If the object storage directory is specified via this
288         environment variable then the sha1 directories are created
289         underneath - otherwise the default `$GIT_DIR/objects`
290         directory is used.
291
292 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
293         Due to the immutable nature of git objects, old objects can be
294         archived into shared, read-only directories. This variable
295         specifies a ":" seperated list of git object directories which
296         can be used to search for git objects. New objects will not be
297         written to these directories.
298
299 'GIT_DIR'::
300         If the 'GIT_DIR' environment variable is set then it specifies
301         a path to use instead of `./.git` for the base of the
302         repository.
303
304 git Commits
305 ~~~~~~~~~~~
306 'GIT_AUTHOR_NAME'::
307 'GIT_AUTHOR_EMAIL'::
308 'GIT_AUTHOR_DATE'::
309 'GIT_COMMITTER_NAME'::
310 'GIT_COMMITTER_EMAIL'::
311         see link:git-commit-tree.html[git-commit-tree]
312
313 git Diffs
314 ~~~~~~~~~
315 'GIT_DIFF_OPTS'::
316 'GIT_EXTERNAL_DIFF'::
317         see the "generating patches" section in :
318         link:git-diff-cache.html[git-diff-cache];
319         link:git-diff-files.html[git-diff-files];
320         link:git-diff-tree.html[git-diff-tree]
321
322 Discussion
323 ----------
324 include::../README[]
325
326 Author
327 ------
328 Written by Linus Torvalds <torvalds@osdl.org> and the git-list <git@vger.kernel.org>.
329
330 Documentation
331 --------------
332 Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
333
334 GIT
335 ---
336 Part of the link:git.html[git] suite
337