======================================
HowTo: Determine 3DBM and GSM Projects 
======================================

.. include:: ..\version.h
.. include:: howto-reference.h

.. contents:: Table of Contents
   :backlinks: top

.. The steps for creating a howto are,
..  
..   1. Copy the howto-boilerplate to the desired filename (X).
..   2. Update the index-howto.txt file to have a reference to X.
..   3. Update the howto-reference.h file with the appropriate 
..      reference.

-------
Preface
-------

To illustrate the ability to query the Project Control File (PCF), this
HowTo_ will discuss iterating across a set of directories and reporting
whether or not the project is a GSM or 3DBM.

---------------
Getting Started
---------------

The following script will iterate through the given directory
(defaulting to the current working directory). Open every PCF, and
report whether or not that PCF is a GSM or 3DBM file. The original
source can be found at `rptpcftype.py`__.

.. __: rptpcftype.py

.. Python::

   import fnmatch
   import os
   import sys

   from grail.data import pcf


   def _walk(arg, dirname, fnames):
       # Only consider files that pass this filter. Note that files like
       # rpt110.rpt will pass, but they will have trouble loading later.
       filter = "*10.*"        
       dats = fnmatch.filter(fnames, filter)
       for d in dats:
           path = os.path.join(dirname, d)
           try:
               # If the file was not a PCF file, then we will get a
               # pcf.PCFError, that we catch and ignore.
               p = pcf.Pcf(path)
               print path,
               if p.isgsm():
                   print "is GSM!"
               else:
                   print "is 3DBM!"
           except pcf.PcfError:
               # Not that important, just keep iterating through the files.
               pass


   if __name__=="__main__":
      # See if there is an argument to this program. If not then default to
      # the current working directory.
      try:
          startDir = sys.argv[1]
      except IndexError:
          # Oh well, you didn't supply an argument. We will default to the
          # current working directory.
          startDir = os.getcwd()
      
      print "walking through ", startDir
      os.path.walk(startDir, _walk, None)


In this script we use the :f:`os.path.walk` [#os.path.walk]_ function
from Python to iterate through all the directories starting at the given
:a:`startDir`, and attempt to open up any file that matches the "\*10.\*"
pattern"

---------
Reference
---------

..  [#os.path.walk]

    "os.path" *Python Library Reference*. 21 December 2001. 23 November
    2007.
    <http://www.python.org/doc/2.2/lib/module-os.path.html#l2h-1290>