1 # taken from plone

     2 

     3 import os

     4 

     5 bin_search_path = [

     6     '/usr/bin',

     7     '/usr/local/bin',

     8     ]

     9 

    10 class MissingBinary(Exception): pass

    11 

    12 def bin_search(binary):

    13     """search the bin_search_path  for a given binary

    14     returning its fullname or None"""

    15     result = None

    16     mode   = os.R_OK | os.X_OK

    17     for p in bin_search_path:

    18         path = os.path.join(p, binary)

    19         if os.access(path, mode) == 1:

    20             result = path

    21             break

    22     else:

    23         raise MissingBinary('Unable to find binary "%s"' % binary)

    24     return result