====== Overriding Software Versions ======

Most of the software titles installed in the SBGrid Suite have several versions available. Typically, we try to provide at least three versions of each software package, although very old or very new applications may have fewer versions.

===== Display Available Versions =====
To list the available versions of a software title, you can use the //sbgrid// utility.  Running //sbgrid -l// will list the versions for your current platform.  From a linux machine, a search for CCP4 versions looks like this:

<code>
$ sbgrid -l ccp4

  Linux programs tree:
setenv CCP4_L 6.1.1
#other supported versions: 5.0.2_1 6.0.2 6.1.0 
</code>

The //setenv// line defines the default version.  Running //sbgrid -L// will print the available versions for the three current platforms (OS X PowerPC and Intel, Linux).

Here is a listing of all currently available versions of PHENIX.

<code>
$ sbgrid -L phenix

  Linux programs tree:
setenv PHENIX_L 1.4-3
#other supported versions: 1.4-59

  OS X Intel programs tree:
setenv PHENIX_M 1.4-3
#other supported versions: 1.4-59

  OS X PowerPC programs tree:
setenv PHENIX_M 1.4-3
#other supported versions: 1.4-59
</code>

===== Override Default Version =====
To override the default version of a software title, edit or create a file at $HOME/.sbgrid and create an entry for the desired version. The syntax for specifying the version is the same as the //setenv// lines above.

<code>setenv APPLICATION_L 1.2</code>

APPLICATION_L is the name of the application followed by an underscore and the shorthand initial for the architecture.  We use L for linux, M for OS X Intel/PPC and S for SGI.  The last field on the line is the version you want to use.

When you open a new shell, you will see a message about the overridden version.  The example output below shows CCP4 on linux being changed from the default version:

<code>
Your ~/.sbgrid file was sourced. Default versions have 
been overridden.
------------------------------------------------------
Software            Version
CCP4_L              6.1.1
</code>