What is CVS?

  cvs - Concurrent Versions System

DESCRIPTION
     cvs is a front end to the  rcs(1)  revision  control  system
     which  extends the notion of revision control from a collec-
     tion of files in a single directory to a  hierarchical  col-
     lection  of  directories  consisting  of revision controlled
     files.  These directories and files can be combined together
     to  form  a  software  release.   cvs provides the functions
     necessary to manage these software releases and  to  control
     the  concurrent  editing  of  source  files  among  multiple
     software developers.
  

Setting Up A Repository

What Is A Repository?

For a group to use CVS a single CVS repository must be created. The CVS repository stores a complete copy of all the files and directories which are under version control.

Normally, you never access any of the files in the repository directly. Instead, you use CVS commands to get your own copy of the files, and then work on that copy. When you've finished a set of changes, you check (or "commit") them back into the repository. The repository then contains the changes which you have made, as well as recording exactly what you changed, when you changed it, and other such information.

Specifying A Repository

Creating A Repository

File Permissions in the Repository

Creating Groups on AFS (acpub)

Using CVS

Starting a Project From a Tree of Files

You can now verify that it worked, and remove your original source directory. In the dialog below, the user moves the hyperwag directory to hyperwag.orig then check out the project named hyperwag (the hyperwag.orig directory is a backup in case something didn't work properly).

Starting a Project From Scratch

Getting the Source

You start your favorite editor, hack away at `Reader.cc', and a couple of hours later you have added support for a new week-at-glance language to the Reader hiearchy.

Committing Your Changes

The environment variable $CVSEDITOR determines which editor is started. If $CVSEDITOR is not set, then if the environment variable $EDITOR is set, it will be used. If both $CVSEDITOR and $EDITOR are not set then the editor defaults to vi. If you want to avoid the overhead of starting an editor you can specify the log message on the command line using the `-m' flag instead, like this:

Bringing a File Up to Date

Your modifications to a file are never lost when you use update. If no newer revision exists, running update has no effect. If you have edited the file, and a newer revision is available, CVS will merge all changes into your working copy.

For instance, imagine that you checked out revision 1.4 and started editing it. In the meantime someone else committed revision 1.5, and shortly after that revision 1.6. If you run update on the file now, CVS will incorporate all changes between revision 1.4 and 1.6 into your file.

If any of the changes between 1.4 and 1.6 were made too close to any of the changes you have made, a "conflict" occurs. In such cases a warning is printed, and the resulting file includes both versions of the lines that overlap, delimited by special markers.

Handling Conflicts

      Reader::Reader( const string & filename )
      {
        myFilename = filename;
      }
      

      Reader::Reader( const string & filename )
        : myFilename( filename )
      {
      }     
      

      #include 

      Reader::Reader( const string & filename )
      {
        myFilename = fullPath( filename );
      }     
      

      #include 

      Reader::Reader( const string & filename )
        : myFilename( filename )
      {
      <<<<<<< Reader.cc
        myFilename = fullPath( filename );
      =======
      >>>>>>> 1.6
      }
      

You resolve the conflict by editing the file, removing the markers and the erroneous line. Suppose you end up with this file:

      #include 

      Reader::Reader( const string & filename )
        : myFilename( fullPath( filename ) )
      {
      }
      

CVS Keywords

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