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_dirs = [os.path.join(portable_base, "data")]
  43         xdg_cache_dirs = [os.path.join(portable_base, "cache")]
  44         xdg_config_dirs = [os.path.join(portable_base, "config")]
  45 else:
  46         if os.name == "nt":
  47                 from win32com.shell import shell, shellcon
  48                 appData = shell.SHGetFolderPath(0, shellcon.CSIDL_APPDATA, 0, 0)
  49                 localAppData = shell.SHGetFolderPath(0, shellcon.CSIDL_LOCAL_APPDATA, 0, 0)
  50                 commonAppData = shell.SHGetFolderPath(0, shellcon.CSIDL_COMMON_APPDATA, 0, 0)
  51
  52                 _default_paths = {
  53                         'DATA' : [appData, commonAppData],
  54                         'CACHE' : [localAppData, commonAppData],
  55                         'CONFIG' : [appData, commonAppData],
  56                 }
  57         else:
  58                 _default_paths = {
  59                         'DATA' : [os.path.join(home, '.local', 'share'), '/usr/local/share', '/usr/share'],
  60                         'CACHE' : [os.path.join(home, '.cache'), '/var/cache'],
  61                         'CONFIG' : [os.path.join(home, '.config'), '/etc/xdg'],
  62                 }
  63
  64         def _get_path(home_var, dirs_var, default_paths):
  65                 paths = default_paths
  66
  67                 x = os.environ.get(home_var, None)
  68                 if x is not None:
  69                         paths[0] = x
  70
  71                 x = os.environ.get(dirs_var, None)
  72                 if x is not None:
  73                         paths[1:] = filter(None, x.split(os.path.pathsep))
  74
  75                 return paths
  76
  77         xdg_data_dirs = _get_path('XDG_DATA_HOME', 'XDG_DATA_DIRS', _default_paths['DATA'])
  78         xdg_cache_dirs = _get_path('XDG_CACHE_HOME', 'XDG_CACHE_DIRS', _default_paths['CACHE'])
  79         xdg_config_dirs = _get_path('XDG_CONFIG_HOME', 'XDG_CONFIG_DIRS', _default_paths['CONFIG'])
  80
  81 # Maybe we should get rid of these?
  82 xdg_data_home = xdg_data_dirs[0]
  83 xdg_cache_home = xdg_cache_dirs[0]
  84 xdg_config_home = xdg_config_dirs[0]
  85
  86 def save_config_path(*resource):
  87         """Ensure $XDG_CONFIG_HOME/<resource>/ exists, and return its path.
  88         'resource' should normally be the name of your application. Use this
  89         when SAVING configuration settings. Use the xdg_config_dirs variable
  90         for loading."""
  91         resource = os.path.join(*resource)
  92         assert not os.path.isabs(resource)
  93         path = os.path.join(xdg_config_home, resource)
  94         if not os.path.isdir(path):
  95                 os.makedirs(path, 0o700)
  96         return path
  97
  98 def load_config_paths(*resource):
  99         """Returns an iterator which gives each directory named 'resource' in the
 100         configuration search path. Information provided by earlier directories should
 101         take precedence over later ones (ie, the user's config dir comes first)."""
 102         resource = os.path.join(*resource)
 103         for config_dir in xdg_config_dirs:
 104                 path = os.path.join(config_dir, resource)
 105                 if os.path.exists(path): yield path
 106
 107 def load_first_config(*resource):
 108         """Returns the first result from load_config_paths, or None if there is nothing
 109         to load."""
 110         for x in load_config_paths(*resource):
 111                 return x
 112         return None
 113
 114 def save_cache_path(*resource):
 115         """Ensure $XDG_CACHE_HOME/<resource>/ exists, and return its path.
 116         'resource' should normally be the name of your application."""
 117         resource = os.path.join(*resource)
 118         assert not os.path.isabs(resource)
 119         path = os.path.join(xdg_cache_home, resource)
 120         if not os.path.isdir(path):
 121                 os.makedirs(path, 0o700)
 122         return path
 123
 124 def load_cache_paths(*resource):
 125         """Returns an iterator which gives each directory named 'resource' in the
 126         cache search path. Information provided by earlier directories should
 127         take precedence over later ones (ie, the user's cache dir comes first)."""
 128         resource = os.path.join(*resource)
 129         for cache_dir in xdg_cache_dirs:
 130                 path = os.path.join(cache_dir, resource)
 131                 if os.path.exists(path): yield path
 132
 133 def load_first_cache(*resource):
 134         """Returns the first result from load_cache_paths, or None if there is nothing
 135         to load."""
 136         for x in load_cache_paths(*resource):
 137                 return x
 138         return None
 139
 140 def load_data_paths(*resource):
 141         """Returns an iterator which gives each directory named 'resource' in the
 142         shared data search path. Information provided by earlier directories should
 143         take precedence over later ones.
 144         @since: 0.28"""
 145         resource = os.path.join(*resource)
 146         for data_dir in xdg_data_dirs:
 147                 path = os.path.join(data_dir, resource)
 148                 if os.path.exists(path): yield path
 149
 150 def load_first_data(*resource):
 151         """Returns the first result from load_data_paths, or None if there is nothing
 152         to load.
 153         @since: 0.28"""
 154         for x in load_data_paths(*resource):
 155                 return x
 156         return None
 157
 158 def save_data_path(*resource):
 159         """Ensure $XDG_DATA_HOME/<resource>/ exists, and return its path.
 160         'resource' should normally be the name of your application."""
 161         resource = os.path.join(*resource)
 162         assert not os.path.isabs(resource)
 163         path = os.path.join(xdg_data_home, resource)
 164         if not os.path.isdir(path):
 165                 os.makedirs(path, 0o700)
 166         return path