zeroinstall/injector/basedir.py

   1 """
   2 Support code for the freedesktop.org basedir spec.
   3
   4 This module provides functions for locating configuration files.
   5
   6 @see: U{http://freedesktop.org/wiki/Standards/basedir-spec}
   7 """
   8
   9 # Copyright (C) 2006, Thomas Leonard
  10 # See the README file for details, or visit http://0install.net.
  11
  12 import os
  13
  14 _home = os.environ.get('HOME', '/')
  15
  16 xdg_data_home = os.environ.get('XDG_DATA_HOME',
  17                         os.path.join(_home, '.local', 'share'))
  18
  19 xdg_data_dirs = [xdg_data_home] + \
  20         os.environ.get('XDG_DATA_DIRS', '/usr/local/share:/usr/share').split(':')
  21
  22 xdg_cache_home = os.environ.get('XDG_CACHE_HOME',
  23                         os.path.join(_home, '.cache'))
  24
  25 xdg_cache_dirs = [xdg_cache_home] + \
  26         os.environ.get('XDG_CACHE_DIRS', '/var/cache').split(':')
  27
  28 xdg_config_home = os.environ.get('XDG_CONFIG_HOME',
  29                         os.path.join(_home, '.config'))
  30
  31 xdg_config_dirs = [xdg_config_home] + \
  32         os.environ.get('XDG_CONFIG_DIRS', '/etc/xdg').split(':')
  33
  34 xdg_data_dirs = filter(lambda x: x, xdg_data_dirs)
  35 xdg_cache_dirs = filter(lambda x: x, xdg_cache_dirs)
  36 xdg_config_dirs = filter(lambda x: x, xdg_config_dirs)
  37
  38 def save_config_path(*resource):
  39         """Ensure $XDG_CONFIG_HOME/<resource>/ exists, and return its path.
  40         'resource' should normally be the name of your application. Use this
  41         when SAVING configuration settings. Use the xdg_config_dirs variable
  42         for loading."""
  43         resource = os.path.join(*resource)
  44         assert not resource.startswith('/')
  45         path = os.path.join(xdg_config_home, resource)
  46         if not os.path.isdir(path):
  47                 os.makedirs(path, 0700)
  48         return path
  49
  50 def load_config_paths(*resource):
  51         """Returns an iterator which gives each directory named 'resource' in the
  52         configuration search path. Information provided by earlier directories should
  53         take precedence over later ones (ie, the user's config dir comes first)."""
  54         resource = os.path.join(*resource)
  55         for config_dir in xdg_config_dirs:
  56                 path = os.path.join(config_dir, resource)
  57                 if os.path.exists(path): yield path
  58
  59 def load_first_config(*resource):
  60         """Returns the first result from load_config_paths, or None if there is nothing
  61         to load."""
  62         for x in load_config_paths(*resource):
  63                 return x
  64         return None
  65
  66 def save_cache_path(*resource):
  67         """Ensure $XDG_CACHE_HOME/<resource>/ exists, and return its path.
  68         'resource' should normally be the name of your application."""
  69         resource = os.path.join(*resource)
  70         assert not resource.startswith('/')
  71         path = os.path.join(xdg_cache_home, resource)
  72         if not os.path.isdir(path):
  73                 os.makedirs(path, 0700)
  74         return path
  75
  76 def load_cache_paths(*resource):
  77         """Returns an iterator which gives each directory named 'resource' in the
  78         cache search path. Information provided by earlier directories should
  79         take precedence over later ones (ie, the user's cache dir comes first)."""
  80         resource = os.path.join(*resource)
  81         for cache_dir in xdg_cache_dirs:
  82                 path = os.path.join(cache_dir, resource)
  83                 if os.path.exists(path): yield path
  84
  85 def load_first_cache(*resource):
  86         """Returns the first result from load_cache_paths, or None if there is nothing
  87         to load."""
  88         for x in load_cache_paths(*resource):
  89                 return x
  90         return None
  91
  92 def load_data_paths(*resource):
  93         """Returns an iterator which gives each directory named 'resource' in the
  94         shared data search path. Information provided by earlier directories should
  95         take precedence over later ones.
  96         @since: 0.28"""
  97         resource = os.path.join(*resource)
  98         for data_dir in xdg_data_dirs:
  99                 path = os.path.join(data_dir, resource)
 100                 if os.path.exists(path): yield path
 101
 102 def load_first_data(*resource):
 103         """Returns the first result from load_data_paths, or None if there is nothing
 104         to load.
 105         @since: 0.28"""
 106         for x in load_data_paths(*resource):
 107                 return x
 108         return None