python/rox/basedir.py

   1 """The freedesktop.org Base Directory specification provides a way for
   2 applications to locate shared data and configuration:
   3
   4         http://www.freedesktop.org/standards/
   5
   6 This module can be used to load and save from and to these directories.
   7
   8 Typical usage:
   9
  10         from rox import basedir
  11
  12         for dir in basedir.load_config_paths('mydomain.org', 'MyProg', 'Options'):
  13                 print "Load settings from", dir
  14
  15         dir = basedir.save_config_path('mydomain.org', 'MyProg')
  16         print >>file(os.path.join(dir, 'Options'), 'w'), "foo=2"
  17
  18 Note: see the rox.Options module for a higher-level API for managing options.
  19 """
  20
  21 from __future__ import generators
  22 import os
  23
  24 _home = os.environ.get('HOME', '/')
  25 xdg_data_home = os.environ.get('XDG_DATA_HOME',
  26                         os.path.join(_home, '.local', 'share'))
  27
  28 xdg_data_dirs = [xdg_data_home] + \
  29         os.environ.get('XDG_DATA_DIRS', '/usr/local/share:/usr/share').split(':')
  30
  31 xdg_config_home = os.environ.get('XDG_CONFIG_HOME',
  32                         os.path.join(_home, '.config'))
  33
  34 xdg_config_dirs = [xdg_config_home] + \
  35         os.environ.get('XDG_CONFIG_DIRS', '/etc/xdg').split(':')
  36
  37 xdg_data_dirs = filter(lambda x: x, xdg_data_dirs)
  38 xdg_config_dirs = filter(lambda x: x, xdg_config_dirs)
  39
  40 def save_config_path(*resource):
  41         """Ensure $XDG_CONFIG_HOME/<resource>/ exists, and return its path.
  42         'resource' should normally be the name of your application. Use this
  43         when SAVING configuration settings. Use the xdg_config_dirs variable
  44         for loading."""
  45         resource = os.path.join(*resource)
  46         assert not resource.startswith('/')
  47         path = os.path.join(xdg_config_home, resource)
  48         if not os.path.isdir(path):
  49                 os.makedirs(path, 0700)
  50         return path
  51
  52 def save_data_path(*resource):
  53         """Ensure $XDG_DATA_HOME/<resource>/ exists, and return its path.
  54         'resource' is the name of some shared resource. Use this when updating
  55         a shared (between programs) database. Use the xdg_data_dirs variable
  56         for loading."""
  57         resource = os.path.join(*resource)
  58         assert not resource.startswith('/')
  59         path = os.path.join(xdg_data_home, resource)
  60         if not os.path.isdir(path):
  61                 os.makedirs(path)
  62         return path
  63
  64 def load_config_paths(*resource):
  65         """Returns an iterator which gives each directory named 'resource' in the
  66         configuration search path. Information provided by earlier directories should
  67         take precedence over later ones (ie, the user's config dir comes first)."""
  68         resource = os.path.join(*resource)
  69         for config_dir in xdg_config_dirs:
  70                 path = os.path.join(config_dir, resource)
  71                 if os.path.exists(path): yield path
  72
  73 def load_first_config(*resource):
  74         """Returns the first result from load_config_paths, or None if there is nothing
  75         to load."""
  76         for x in load_config_paths(*resource):
  77                 return x
  78         return None
  79
  80 def load_data_paths(*resource):
  81         """Returns an iterator which gives each directory named 'resource' in the
  82         shared data search path. Information provided by earlier directories should
  83         take precedence over later ones."""
  84         resource = os.path.join(*resource)
  85         for data_dir in xdg_data_dirs:
  86                 path = os.path.join(data_dir, resource)
  87                 if os.path.exists(path): yield path