zeroinstall/support/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 @var home: The value of $HOME (or '/' if not set). If we're running as root and
   9 $HOME isn't owned by root, then this will be root's home from /etc/passwd
  10 instead.
  11 """
  12
  13 # Copyright (C) 2009, Thomas Leonard
  14 # See the README file for details, or visit http://0install.net.
  15
  16 from zeroinstall import _
  17 import os
  18
  19 home = os.environ.get('HOME', '/')
  20
  21 try:
  22         _euid = os.geteuid()
  23 except AttributeError:
  24         pass    # Windows?
  25 else:
  26         if _euid == 0:
  27                 # We're running as root. Ensure that $HOME really is root's home,
  28                 # not the user's home, or we're likely to fill it will unreadable
  29                 # root-owned files.
  30                 home_owner = os.stat(home).st_uid
  31                 if home_owner != 0:
  32                         import pwd
  33                         from logging import info
  34                         old_home = home
  35                         home = pwd.getpwuid(0).pw_dir or '/'
  36                         info(_("$HOME (%(home)s) is owned by user %(user)d, but we are root (0). Using %(root_home)s instead."), {'home': old_home, 'user': home_owner, 'root_home': home})
  37                         del old_home
  38                         del home_owner
  39
  40 portable_base = os.environ.get('ZEROINSTALL_PORTABLE_BASE')
  41 if portable_base:
  42         xdg_data_home = os.path.join(portable_base, "data")
  43         xdg_data_dirs = [xdg_data_home]
  44         xdg_cache_home = os.path.join(portable_base, "cache")
  45         xdg_cache_dirs = [xdg_cache_home]
  46         xdg_config_home = os.path.join(portable_base, "config")
  47         xdg_config_dirs = [xdg_config_home]
  48 elif os.name == "nt":
  49         from win32com.shell import shell, shellcon
  50         appData = shell.SHGetFolderPath(0, shellcon.CSIDL_APPDATA, 0, 0)
  51         localAppData = shell.SHGetFolderPath(0, shellcon.CSIDL_LOCAL_APPDATA, 0, 0)
  52         commonAppData = shell.SHGetFolderPath(0, shellcon.CSIDL_COMMON_APPDATA, 0, 0)
  53
  54         xdg_data_home = appData
  55         xdg_data_dirs = [xdg_data_home, commonAppData]
  56
  57         xdg_cache_home = localAppData
  58         xdg_cache_dirs = [xdg_cache_home, commonAppData]
  59
  60         xdg_config_home = appData
  61         xdg_config_dirs = [xdg_config_home, commonAppData]
  62 else:
  63         xdg_data_home = os.environ.get('XDG_DATA_HOME',
  64                                 os.path.join(home, '.local', 'share'))
  65
  66         xdg_data_dirs = [xdg_data_home] + \
  67                 os.environ.get('XDG_DATA_DIRS', '/usr/local/share:/usr/share').split(':')
  68
  69         xdg_cache_home = os.environ.get('XDG_CACHE_HOME',
  70                                 os.path.join(home, '.cache'))
  71
  72         xdg_cache_dirs = [xdg_cache_home] + \
  73                 os.environ.get('XDG_CACHE_DIRS', '/var/cache').split(':')
  74
  75         xdg_config_home = os.environ.get('XDG_CONFIG_HOME',
  76                                 os.path.join(home, '.config'))
  77
  78         xdg_config_dirs = [xdg_config_home] + \
  79                 os.environ.get('XDG_CONFIG_DIRS', '/etc/xdg').split(':')
  80
  81 xdg_data_dirs = filter(lambda x: x, xdg_data_dirs)
  82 xdg_cache_dirs = filter(lambda x: x, xdg_cache_dirs)
  83 xdg_config_dirs = filter(lambda x: x, xdg_config_dirs)
  84
  85 def save_config_path(*resource):
  86         """Ensure $XDG_CONFIG_HOME/<resource>/ exists, and return its path.
  87         'resource' should normally be the name of your application. Use this
  88         when SAVING configuration settings. Use the xdg_config_dirs variable
  89         for loading."""
  90         resource = os.path.join(*resource)
  91         assert not os.path.isabs(resource)
  92         path = os.path.join(xdg_config_home, resource)
  93         if not os.path.isdir(path):
  94                 os.makedirs(path, 0o700)
  95         return path
  96
  97 def load_config_paths(*resource):
  98         """Returns an iterator which gives each directory named 'resource' in the
  99         configuration search path. Information provided by earlier directories should
 100         take precedence over later ones (ie, the user's config dir comes first)."""
 101         resource = os.path.join(*resource)
 102         for config_dir in xdg_config_dirs:
 103                 path = os.path.join(config_dir, resource)
 104                 if os.path.exists(path): yield path
 105
 106 def load_first_config(*resource):
 107         """Returns the first result from load_config_paths, or None if there is nothing
 108         to load."""
 109         for x in load_config_paths(*resource):
 110                 return x
 111         return None
 112
 113 def save_cache_path(*resource):
 114         """Ensure $XDG_CACHE_HOME/<resource>/ exists, and return its path.
 115         'resource' should normally be the name of your application."""
 116         resource = os.path.join(*resource)
 117         assert not os.path.isabs(resource)
 118         path = os.path.join(xdg_cache_home, resource)
 119         if not os.path.isdir(path):
 120                 os.makedirs(path, 0o700)
 121         return path
 122
 123 def load_cache_paths(*resource):
 124         """Returns an iterator which gives each directory named 'resource' in the
 125         cache search path. Information provided by earlier directories should
 126         take precedence over later ones (ie, the user's cache dir comes first)."""
 127         resource = os.path.join(*resource)
 128         for cache_dir in xdg_cache_dirs:
 129                 path = os.path.join(cache_dir, resource)
 130                 if os.path.exists(path): yield path
 131
 132 def load_first_cache(*resource):
 133         """Returns the first result from load_cache_paths, or None if there is nothing
 134         to load."""
 135         for x in load_cache_paths(*resource):
 136                 return x
 137         return None
 138
 139 def load_data_paths(*resource):
 140         """Returns an iterator which gives each directory named 'resource' in the
 141         shared data search path. Information provided by earlier directories should
 142         take precedence over later ones.
 143         @since: 0.28"""
 144         resource = os.path.join(*resource)
 145         for data_dir in xdg_data_dirs:
 146                 path = os.path.join(data_dir, resource)
 147                 if os.path.exists(path): yield path
 148
 149 def load_first_data(*resource):
 150         """Returns the first result from load_data_paths, or None if there is nothing
 151         to load.
 152         @since: 0.28"""
 153         for x in load_data_paths(*resource):
 154                 return x
 155         return None