A CVS Tutorial for NuTeV

This is a step-by-step set of instructions on how to use CVS, written for the users on experiment E815. The first list explains how to get the source code for a product and use it for your own applications.

Getting a new Product

The basics of getting a new product is fairly easy. Most (but not neccessarily all) products are designed with a Makefile so that you can create a default executable and start running immediately. 
1. (Optional) > mkdir productdir

2. (Optional) > cd productdir

3.            > cvs checkout productname

4.            > cd productname

5.            > make
You should always check the README document, if there is one, or consult other sources. See the list of Software Available in CVS for product names and links to WWW documentation.

1-2 (Optional): Creating a product directory.
CVS will make its own directory for the source code it takes from the repository. However, if you are going to be significantly customizing or adding to the code, it is helpful to have a personal area separate from the ``pure'' product code.

3: Checking out the product.
This creates a new subdirectory of the current directory, with a directory name the same as the name of the product.
4-5: Making the executable.
Several products have a default Makefile which lets you create an executable quickly. You should check for the specifics, however.
For more details on this, see the section on cvs checkout in the full documentation.

Updating Your Version

In order to get all the updates which have been made to the product, simply go into the productname directory and say: 
1.       > cvs update -d
CVS will automatically merge the changes made to the repository and the changes which you have made. It will keep what changes you have made, and overlay the changes which have been made to the repository. This is indicated by the output which the cvs update command produces, which looks something like: 

U afile.F
M changedfile.F
U driver.F
A newfile.F
? userfile.f
The single-letter code on the left indicates what has happened to that file. The only code which you have to worry about would be a `C' - which would indicate that your changes and the repository changes conflict. This means that you have to go into that file, and edit it to be the version which you want. Within the file, you will find something like: 

>>>>>>>>>>>>>>>>>>>
   avar = value1
>>>>>>>>>>>>>>>>>>>
<<<<<<<<<<<<<<<<<<<
   avar = value2
<<<<<<<<<<<<<<<<<<<
The first code is the repository change, the second is the change which you made. You have to delete the version you don't want, and remove all the >'s and <'s.

The other codes mean the following:

For more details on this, see the section on cvs add in the full documentation.

Committing Changes to the Central Repository

The most important thing to remember in committing is to be careful. Test the code exactly as it will appear in the repository (i.e. no user-only routines or changes). You should inform whoever is in charge of that code what you are going to do. Assuming he or she approves, then the steps are as follows:

> setenv EDITOR yourfavorite
This line should probably be added to your .login file.
(Optional) > cvs add newfilename
If you are adding a new file or directory to the repository, you must specify it in advance of committing. Otherwise CVS will just ignore it.
> cvs commit filename
This commits the changes you have made to file filename to the central repository. If you leave filename blank, it will commit all the changes you have made to the code.

Upon the commit command, CVS will demand from you a comment for the record on the changes which you have done (using the editor defined in the first step). For most significant changes, you should also send a note to the NuTeV Bank System.

For more details on this, see the section on cvs commit in the full documentation.