Introduction
At times we need to build a new version of the skimmer, or build a version for a particular OS or version of ROOT. Documentation concerning the skimmer is available in our Confluence pages here:
https://confluence.slac.stanford.edu/display/ds/Skimmer+at+Slac, which references the more recent documentation: http://llr.in2p3.fr/trac/tskim/wiki/FermiGuide
The instructions here differ somewhat from what is written in the FermiGuide.
Installation Area
We install the skimmer at SLAC in:
/afs/slac.stanford.edu/g/glast/ground/DataServer
Source Code
If the source for the version of the skimmer you are interested is not already available in the DataServer directory, you will have to obtain it from the Subversion repository maintained by David Chamont.
Details can be found here: http://llr.in2p3.fr/trac/tskim/wiki/Download
David is following our SCons-like tagging convention of the form xx-xx-xx. The most recent tag as of December 1, 2009 is 07-07-00.
Compiling Skimmer
In the bin directory of the skimmer distribution, you will see two scripts: make_fermi and make_tskim.
Note: Some earlier versions of the skimmer may have a script named make_skimmer in place of the more recent make_fermi script.
make_fermi will attempt to build the skimmer for both RHEL3 and RHEL4-32 using a variety of versions of ROOT. We use this script if this is a fresh installation of a version of the skimmer. There is no set up required to use this script. Just run make_fermi and the skimmer will be built.
make_tskim builds a specific version of the skimmer for a version of ROOT on a particular operating system. We use this script when we desire to build the skimmer against a specific version of ROOT on a particular operating system. To use this script, we need to set ROOTSYS as well as GLAST_EXT appropriately.
Location of the Binaries
Starting with skimmer v7r4, the skimmer binaries are placed under the bin directory. Previously, a new directory named linux would be generated and the binaries placed there - without a means to differentiate between OS or -gl* versions of ROOT.