Normally one uses the dataCatalog to identify and then either download or skim data files of interest. Upon occasion, there may be reasons for wishing to perform this function manually, such as if the "crawler" has not yet filled in certain crucial information in the dataCatalog and, thereby, preventing downloading and skimming. There are two basic steps to this process.

  1. Generate a list of files in xroot to download
  2. Copy the files to some available local disk space

*Details*

Step 1 can be accomplished a number of ways. The easiest is to use the dataCatalog, navigate to the task and file type of interest and then click the "Dump file list (SLAC_XROOT)" link, wherein you may then copy/paste the result into a text file. Xroot filename specifications look like this example:

root://glast-rdr//glast/mc/ServiceChallenge/allGammaOBF1-GR-v13r9p3/merit/allGammaOBF1-GR-v13r9p3-000002-merit.root

If the dataCatalog is not available, you may look into any of the task's log files or even guess the filenames based on their systematic and mostly predictable name construction,

root://glast-rdr//glast/mc/<taskCategory>/<taskName>/<fileType>/<taskName>-GR-<GlastRelease>-<streamNumber>-<dataType>.root

Step 2 can be accomplished manually copying/pasting each file name onto the appropriate command line, e.g.,

/afs/slac.stanford.edu/g/glast/applications/xrootd/PROD/bin/xrdcp root://glast-rdr//glast/mc/ServiceChallenge/allGammaOBF1-GR-v13r9p3/merit/allGammaOBF1-GR-v13r9p3-000002-merit.root .

Other options including using the unix "xargs" command or, if one is truly brave, a work-in-progress script called cpxrd.py which takes as an argument the name of a file containing a list of xroot files and then copies them all to your current working directory, e.g., assume "filelist" is a text file containing the names of five xroot files, then

$ /u/ec/dragon/glast/cpxrd/cpxrd.py filelist
args =  ['../cpxrd.py', 'filelist']
Number of arguments passed =  2
%INFO: 20080225:14:23:21 - cpxrd(<module>)/line-86 - READ MODE
%INFO: 20080225:14:23:21 - cpxrd(<module>)/line-141 -
         Read 5 lines from filelist

xrdcp command:
/afs/slac.stanford.edu/g/glast/applications/xrootd/PROD/bin/xrdcp root://glast-rdr//glast/mc/ServiceChallenge/allGammaOBF1-GR-v13r9p3/merit/allGammaOBF1-GR-v13r9p3-000000-merit.root .
[xrootd] Total 1.80 MB  |====================| 100.00 % [7.3 MB/s]
xrdcp command:
/afs/slac.stanford.edu/g/glast/applications/xrootd/PROD/bin/xrdcp root://glast-rdr//glast/mc/ServiceChallenge/allGammaOBF1-GR-v13r9p3/merit/allGammaOBF1-GR-v13r9p3-000001-merit.root .
[xrootd] Total 1.74 MB  |====================| 100.00 % [7.1 MB/s]
xrdcp command:
/afs/slac.stanford.edu/g/glast/applications/xrootd/PROD/bin/xrdcp root://glast-rdr//glast/mc/ServiceChallenge/allGammaOBF1-GR-v13r9p3/merit/allGammaOBF1-GR-v13r9p3-000002-merit.root .
[xrootd] Total 1.77 MB  |====================| 100.00 % [7.1 MB/s]
xrdcp command:
/afs/slac.stanford.edu/g/glast/applications/xrootd/PROD/bin/xrdcp root://glast-rdr//glast/mc/ServiceChallenge/allGammaOBF1-GR-v13r9p3/merit/allGammaOBF1-GR-v13r9p3-000003-merit.root .
[xrootd] Total 1.75 MB  |====================| 100.00 % [7.1 MB/s]
xrdcp command:
/afs/slac.stanford.edu/g/glast/applications/xrootd/PROD/bin/xrdcp root://glast-rdr//glast/mc/ServiceChallenge/allGammaOBF1-GR-v13r9p3/merit/allGammaOBF1-GR-v13r9p3-000004-merit.root .
[xrootd] Total 1.75 MB  |====================| 100.00 % [6.9 MB/s]