1GITCVS-MIGRATION(7) Git Manual GITCVS-MIGRATION(7)
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6 gitcvs-migration - Git for CVS users
7
9 git cvsimport *
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12 Git differs from CVS in that every working tree contains a repository
13 with a full copy of the project history, and no repository is
14 inherently more important than any other. However, you can emulate the
15 CVS model by designating a single shared repository which people can
16 synchronize with; this document explains how to do that.
17 Some basic familiarity with Git is required. Having gone through
19 gittutorial(7) and gitglossary(7) should be sufficient.
20
22 Suppose a shared repository is set up in /pub/repo.git on the host
23 foo.com. Then as an individual committer you can clone the shared
24 repository over ssh with:
25 $ git clone foo.com:/pub/repo.git/ my-project
27 $ cd my-project
28 and hack away. The equivalent of cvs update is
30 $ git pull origin
32 which merges in any work that others might have done since the clone
34 operation. If there are uncommitted changes in your working tree,
35 commit them first before running git pull.
36 Note
38 The pull command knows where to get updates from because of certain
39 configuration variables that were set by the first git clone
40 command; see git config -l and the git-config(1) man page for
41 details.
42 You can update the shared repository with your changes by first
44 committing your changes, and then using the git push command:
45 $ git push origin master
47 to "push" those commits to the shared repository. If someone else has
49 updated the repository more recently, git push, like cvs commit, will
50 complain, in which case you must pull any changes before attempting the
51 push again.
52 In the git push command above we specify the name of the remote branch
54 to update (master). If we leave that out, git push tries to update any
55 branches in the remote repository that have the same name as a branch
56 in the local repository. So the last push can be done with either of:
57 $ git push origin
59 $ git push foo.com:/pub/project.git/
60 as long as the shared repository does not have any branches other than
62 master.
63
65 We assume you have already created a Git repository for your project,
66 possibly created from scratch or from a tarball (see gittutorial(7)),
67 or imported from an already existing CVS repository (see the next
68 section).
69 Assume your existing repo is at /home/alice/myproject. Create a new
71 "bare" repository (a repository without a working tree) and fetch your
72 project into it:
73 $ mkdir /pub/my-repo.git
75 $ cd /pub/my-repo.git
76 $ git --bare init --shared
77 $ git --bare fetch /home/alice/myproject master:master
78 Next, give every team member read/write access to this repository. One
80 easy way to do this is to give all the team members ssh access to the
81 machine where the repository is hosted. If you don’t want to give them
82 a full shell on the machine, there is a restricted shell which only
83 allows users to do Git pushes and pulls; see git-shell(1).
84 Put all the committers in the same group, and make the repository
86 writable by that group:
87 $ chgrp -R $group /pub/my-repo.git
89 Make sure committers have a umask of at most 027, so that the
91 directories they create are writable and searchable by other group
92 members.
93
95 Note
96 These instructions use the git-cvsimport script which ships with
97 git, but other importers may provide better results. See the note
98 in git-cvsimport(1) for other options.
99 First, install version 2.1 or higher of cvsps from
101 https://github.com/andreyvit/cvsps and make sure it is in your path.
102 Then cd to a checked out CVS working directory of the project you are
103 interested in and run git-cvsimport(1):
104 $ git cvsimport -C <destination> <module>
106 This puts a Git archive of the named CVS module in the directory
108 <destination>, which will be created if necessary.
109 The import checks out from CVS every revision of every file. Reportedly
111 cvsimport can average some twenty revisions per second, so for a
112 medium-sized project this should not take more than a couple of
113 minutes. Larger projects or remote repositories may take longer.
114 The main trunk is stored in the Git branch named origin, and additional
116 CVS branches are stored in Git branches with the same names. The most
117 recent version of the main trunk is also left checked out on the master
118 branch, so you can start adding your own changes right away.
119 The import is incremental, so if you call it again next month it will
121 fetch any CVS updates that have been made in the meantime. For this to
122 work, you must not modify the imported branches; instead, create new
123 branches for your own changes, and merge in the imported branches as
124 necessary.
125 If you want a shared repository, you will need to make a bare clone of
127 the imported directory, as described above. Then treat the imported
128 directory as another development clone for purposes of merging
129 incremental imports.
130
132 Git allows you to specify scripts called "hooks" to be run at certain
133 points. You can use these, for example, to send all commits to the
134 shared repository to a mailing list. See githooks(5).
135 You can enforce finer grained permissions using update hooks. See
137 Controlling access to branches using update hooks[1].
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140 It is also possible to provide true CVS access to a Git repository, so
141 that developers can still use CVS; see git-cvsserver(1) for details.
142
144 CVS users are accustomed to giving a group of developers commit access
145 to a common repository. As we’ve seen, this is also possible with Git.
146 However, the distributed nature of Git allows other development models,
147 and you may want to first consider whether one of them might be a
148 better fit for your project.
149 For example, you can choose a single person to maintain the project’s
151 primary public repository. Other developers then clone this repository
152 and each work in their own clone. When they have a series of changes
153 that they’re happy with, they ask the maintainer to pull from the
154 branch containing the changes. The maintainer reviews their changes and
155 pulls them into the primary repository, which other developers pull
156 from as necessary to stay coordinated. The Linux kernel and other
157 projects use variants of this model.
158 With a small group, developers may just pull changes from each other’s
160 repositories without the need for a central maintainer.
161
163 gittutorial(7), gittutorial-2(7), gitcore-tutorial(7), gitglossary(7),
164 giteveryday(7), The Git User’s Manual[2]
165
167 Part of the git(1) suite
168
170 1. Controlling access to branches using update hooks
171 file:///usr/share/doc/git/howto/update-hook-example.html
172 2. The Git User’s Manual
174 file:///usr/share/doc/git/user-manual.html
175Git 2.39.1 2023-01-13 GITCVS-MIGRATION(7)