GITCVS-MIGRATION(7)       (08/17/2021)        GITCVS-MIGRATION(7)

     NAME
          gitcvs-migration - Git for CVS users

     SYNOPSIS
          git cvsimport *

     DESCRIPTION
          Git differs from CVS in that every working tree contains a
          repository with a full copy of the project history, and no
          repository is inherently more important than any other.
          However, you can emulate the CVS model by designating a
          single shared repository which people can synchronize with;
          this document explains how to do that.

          Some basic familiarity with Git is required. Having gone
          through gittutorial(7) and gitglossary(7) should be
          sufficient.

     DEVELOPING AGAINST A SHARED REPOSITORY
          Suppose a shared repository is set up in /pub/repo.git on
          the host foo.com. Then as an individual committer you can
          clone the shared repository over ssh with:

              $ git clone foo.com:/pub/repo.git/ my-project
              $ cd my-project

          and hack away. The equivalent of cvs update is

              $ git pull origin

          which merges in any work that others might have done since
          the clone operation. If there are uncommitted changes in
          your working tree, commit them first before running git
          pull.

              Note

              The pull command knows where to get updates from because
              of certain configuration variables that were set by the
              first git clone command; see git config -l and the git-
              config(1) man page for details.

          You can update the shared repository with your changes by
          first committing your changes, and then using the git push
          command:

              $ git push origin master

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          to "push" those commits to the shared repository. If someone
          else has updated the repository more recently, git push,
          like cvs commit, will complain, in which case you must pull
          any changes before attempting the push again.

          In the git push command above we specify the name of the
          remote branch to update (master). If we leave that out, git
          push tries to update any branches in the remote repository
          that have the same name as a branch in the local repository.
          So the last push can be done with either of:

              $ git push origin
              $ git push foo.com:/pub/project.git/

          as long as the shared repository does not have any branches
          other than master.

     SETTING UP A SHARED REPOSITORY
          We assume you have already created a Git repository for your
          project, possibly created from scratch or from a tarball
          (see gittutorial(7)), or imported from an already existing
          CVS repository (see the next section).

          Assume your existing repo is at /home/alice/myproject.
          Create a new "bare" repository (a repository without a
          working tree) and fetch your project into it:

              $ mkdir /pub/my-repo.git
              $ cd /pub/my-repo.git
              $ git --bare init --shared
              $ git --bare fetch /home/alice/myproject master:master

          Next, give every team member read/write access to this
          repository. One easy way to do this is to give all the team
          members ssh access to the machine where the repository is
          hosted. If you doncqt want to give them a full shell on the
          machine, there is a restricted shell which only allows users
          to do Git pushes and pulls; see git-shell(1).

          Put all the committers in the same group, and make the
          repository writable by that group:

              $ chgrp -R $group /pub/my-repo.git

          Make sure committers have a umask of at most 027, so that
          the directories they create are writable and searchable by
          other group members.

     IMPORTING A CVS ARCHIVE

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              Note

              These instructions use the git-cvsimport script which
              ships with git, but other importers may provide better
              results. See the note in git-cvsimport(1) for other
              options.

          First, install version 2.1 or higher of cvsps from
          m[blue]https://github.com/andreyvit/cvspsm[] and make sure
          it is in your path. Then cd to a checked out CVS working
          directory of the project you are interested in and run git-
          cvsimport(1):

              $ git cvsimport -C <destination> <module>

          This puts a Git archive of the named CVS module in the
          directory <destination>, which will be created if necessary.

          The import checks out from CVS every revision of every file.
          Reportedly cvsimport can average some twenty revisions per
          second, so for a medium-sized project this should not take
          more than a couple of minutes. Larger projects or remote
          repositories may take longer.

          The main trunk is stored in the Git branch named origin, and
          additional CVS branches are stored in Git branches with the
          same names. The most recent version of the main trunk is
          also left checked out on the master branch, so you can start
          adding your own changes right away.

          The import is incremental, so if you call it again next
          month it will fetch any CVS updates that have been made in
          the meantime. For this to work, you must not modify the
          imported branches; instead, create new branches for your own
          changes, and merge in the imported branches as necessary.

          If you want a shared repository, you will need to make a
          bare clone of the imported directory, as described above.
          Then treat the imported directory as another development
          clone for purposes of merging incremental imports.

     ADVANCED SHARED REPOSITORY MANAGEMENT
          Git allows you to specify scripts called "hooks" to be run
          at certain points. You can use these, for example, to send
          all commits to the shared repository to a mailing list. See
          githooks(5).

          You can enforce finer grained permissions using update
          hooks. See m[blue]Controlling access to branches using
          update hooksm[][1].


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     PROVIDING CVS ACCESS TO A GIT REPOSITORY
          It is also possible to provide true CVS access to a Git
          repository, so that developers can still use CVS; see git-
          cvsserver(1) for details.

     ALTERNATIVE DEVELOPMENT MODELS
          CVS users are accustomed to giving a group of developers
          commit access to a common repository. As wecqve seen, this is
          also possible with Git. However, the distributed nature of
          Git allows other development models, and you may want to
          first consider whether one of them might be a better fit for
          your project.

          For example, you can choose a single person to maintain the
          projectcqs primary public repository. Other developers then
          clone this repository and each work in their own clone. When
          they have a series of changes that theycqre happy with, they
          ask the maintainer to pull from the branch containing the
          changes. The maintainer reviews their changes and pulls them
          into the primary repository, which other developers pull
          from as necessary to stay coordinated. The Linux kernel and
          other projects use variants of this model.

          With a small group, developers may just pull changes from
          each othercqs repositories without the need for a central
          maintainer.

     SEE ALSO
          gittutorial(7), gittutorial-2(7), gitcore-tutorial(7),
          gitglossary(7), giteveryday(7), m[blue]The Git Usercqs
          Manualm[][2]

     GIT
          Part of the git(1) suite

     NOTES
           1. Controlling access to branches using update hooks
              file:///usr/share/doc/git/html/howto/update-hook-example.html

           2. The Git Usercqs Manual
              file:///usr/share/doc/git/html/user-manual.html

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