Explain how to set up user name/email correctly for git.
[libav.git] / doc / git-howto.txt
1
2 About Git write access:
3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4
5 Before everything else, you should know how to use GIT properly.
6 Luckily Git comes with excellent documentation.
7
8 git --help
9 man git
10
11 shows you the available subcommands,
12
13 git <command> --help
14 man git-<command>
15
16 shows information about the subcommand <command>.
17
18 The most comprehensive manual is the website Git Reference
19
20 http://gitref.org/
21
22 For more information about the Git project, visit
23
24 http://git-scm.com/
25
26 Consult these resources whenever you have problems, they are quite exhaustive.
27
28 You do not need a special username or password.
29 All you need is to provide a ssh public key to the Git server admin.
30
31 What follows now is a basic introduction to Git and some FFmpeg-specific
32 guidelines. Read it at least once, if you are granted commit privileges to the
33 FFmpeg project you are expected to be familiar with these rules.
34
35
36
37 I. BASICS:
38 ==========
39
40 0. Get GIT:
41
42 You can get git from http://git-scm.com/
43
44
45 1. Cloning the source tree:
46
47 git clone git://git.videolan.org/ffmpeg <target>
48
49 This will put the FFmpeg sources into the directory <target>.
50
51 git clone git@git.videolan.org:ffmpeg <target>
52
53 This will put the FFmpeg sources into the directory <target> and let
54 you push back your changes to the remote repository.
55
56
57 2. Updating the source tree to the latest revision:
58
59 git pull (--ff-only)
60
61 pulls in the latest changes from the tracked branch. The tracked branch
62 can be remote. By default the master branch tracks the branch master in
63 the remote origin.
64 Caveat: Since merge commits are forbidden at least for the initial
65 months of git --ff-only or --rebase (see below) are recommended.
66 --ff-only will fail and not create merge commits if your branch
67 has diverged (has a different history) from the tracked branch.
68
69 2.a Rebasing your local branches:
70
71 git pull --rebase
72
73 fetches the changes from the main repository and replays your local commits
74 over it. This is required to keep all your local changes at the top of
75 FFmpeg's master tree. The master tree will reject pushes with merge commits.
76
77
78 3. Adding/removing files/directories:
79
80 git add [-A] <filename/dirname>
81 git rm [-r] <filename/dirname>
82
83 GIT needs to get notified of all changes you make to your working
84 directory that makes files appear or disappear.
85 Line moves across files are automatically tracked.
86
87
88 4. Showing modifications:
89
90 git diff <filename(s)>
91
92 will show all local modifications in your working directory as unified diff.
93
94
95 5. Inspecting the changelog:
96
97 git log <filename(s)>
98
99 You may also use the graphical tools like gitview or gitk or the web
100 interface available at http://git.videolan.org
101
102 6. Checking source tree status:
103
104 git status
105
106 detects all the changes you made and lists what actions will be taken in case
107 of a commit (additions, modifications, deletions, etc.).
108
109
110 7. Committing:
111
112 git diff --check
113
114 to double check your changes before committing them to avoid trouble later
115 on. All experienced developers do this on each and every commit, no matter
116 how small.
117 Every one of them has been saved from looking like a fool by this many times.
118 It's very easy for stray debug output or cosmetic modifications to slip in,
119 please avoid problems through this extra level of scrutiny.
120
121 For cosmetics-only commits you should get (almost) empty output from
122
123 git diff -wb <filename(s)>
124
125 Also check the output of
126
127 git status
128
129 to make sure you don't have untracked files or deletions.
130
131 git add [-i|-p|-A] <filenames/dirnames>
132
133 Make sure you have told git your name and email address, e.g. by running
134 git config --global user.name "My Name"
135 git config --global user.email my@email.invalid
136 (--global to set the global configuration for all your git checkouts).
137
138 Git will select the changes to the files for commit. Optionally you can use
139 the interactive or the patch mode to select hunk by hunk what should be
140 added to the commit.
141
142 git commit
143
144 Git will commit the selected changes to your current local branch.
145
146 You will be prompted for a log message in an editor, which is either
147 set in your personal configuration file through
148
149 git config core.editor
150
151 or set by one of the following environment variables:
152 GIT_EDITOR, VISUAL or EDITOR.
153
154 Log messages should be concise but descriptive. Explain why you made a change,
155 what you did will be obvious from the changes themselves most of the time.
156 Saying just "bug fix" or "10l" is bad. Remember that people of varying skill
157 levels look at and educate themselves while reading through your code. Don't
158 include filenames in log messages, Git provides that information.
159
160 Possibly make the commit message have a terse, descriptive first line, an
161 empty line and then a full description. The first line will be used to name
162 the patch by git format-patch.
163
164
165 8. Renaming/moving/copying files or contents of files:
166
167 Git automatically tracks such changes, making those normal commits.
168
169 mv/cp path/file otherpath/otherfile
170
171 git add [-A] .
172
173 git commit
174
175 Do not move, rename or copy files of which you are not the maintainer without
176 discussing it on the mailing list first!
177
178 9. Reverting broken commits
179
180 git revert <commit>
181
182 git revert will generate a revert commit. This will not make the faulty
183 commit disappear from the history.
184
185 git reset <commit>
186
187 git reset will uncommit the changes till <commit> rewriting the current
188 branch history.
189
190 git commit --amend
191
192 allows to amend the last commit details quickly.
193
194 git rebase -i origin/master
195
196 will replay local commits over the main repository allowing to edit,
197 merge or remove some of them in the process.
198
199 Note that the reset, commit --amend and rebase rewrite history, so you
200 should use them ONLY on your local or topic branches.
201
202 The main repository will reject those changes.
203
204 10. Preparing a patchset.
205
206 git format-patch <commit> [-o directory]
207
208 will generate a set of patches out of the current branch starting from
209 commit. By default the patches are created in the current directory.
210
211 11. Sending patches for review
212
213 git send-email <commit list|directory>
214
215 will send the patches created by git format-patch or directly generates
216 them. All the email fields can be configured in the global/local
217 configuration or overridden by command line.
218
219 12. Pushing changes to remote trees
220
221 git push
222
223 Will push the changes to the default remote (origin).
224 Git will prevent you from pushing changes if the local and remote trees are
225 out of sync. Refer to 2 and 2.a to sync the local tree.
226
227 git remote add <name> <url>
228
229 Will add additional remote with a name reference, it is useful if you want
230 to push your local branch for review on a remote host.
231
232 git push <remote> <refspec>
233
234 Will push the changes to the remote repository. Omitting refspec makes git
235 push update all the remote branches matching the local ones.
236
237 13. Finding a specific svn revision
238
239 Since version 1.7.1 git supports ':/foo' syntax for specifying commits
240 based on a regular expression. see man gitrevisions
241
242 git show :/'as revision 23456'
243
244 will show the svn changeset r23456. With older git versions searching in
245 the git log output is the easiest option (especially if a pager with
246 search capabilities is used).
247 This commit can be checked out with
248
249 git checkout -b svn_23456 :/'as revision 23456'
250
251 or for git < 1.7.1 with
252
253 git checkout -b svn_23456 $SHA1
254
255 where $SHA1 is the commit SHA1 from the 'git log' output.
256
257
258 Contact the project admins <root at ffmpeg dot org> if you have technical
259 problems with the GIT server.