Write out the dynamic OS choice, to avoid exec statements.

Adding support for a new OS is now a bit more work, but I bet that
'dos' or 'nt' will cover most situations...

diff --git a/Lib/os.py b/Lib/os.py
index 51e8a67fca56277f968f24a93231ca2388ddda31..7f9e696f3447906b38bc073f43c7afbd76ec0f50 100644 (file)
--- a/Lib/os.py
+++ b/Lib/os.py
@@ -6,7 +6,8 @@
 # - os.name is either 'posix' or 'mac'
 # - os.curdir is a string representing the current directory ('.' or ':')
 # - os.pardir is a string representing the parent directory ('..' or '::')
-# - os.sep is the (or a most common) pathname separator ('/' or ':')
+# - os.sep is the (or a most common) pathname separator ('/' or ':' or '\\')
+# - os.altsep is the alternatte pathname separator (None or '/')
 # - os.pathsep is the component separator used in $PATH etc
 # - os.defpath is the default search path for executables
 
@@ -16,39 +17,71 @@
 # and opendir), and leave all pathname manipulation to os.path
 # (e.g., split and join).
 
-_osindex = {
-         'posix': ('.', '..', '/', ':', ':/bin:/usr/bin'),
-         'dos':   ('.', '..', '\\', ';', '.;C:\\bin'),
-         'nt':    ('.', '..', '\\', ';', '.;C:\\bin'),
-         'mac':   (':', '::', ':', '\n', ':'),
-}
+import sys
 
-# For freeze.py script:
-if 0:
-       import posix
-       import posixpath
+_names = sys.builtin_module_names
 
-import sys
-for name in _osindex.keys():
-       if name in sys.builtin_module_names:
-               curdir, pardir, sep, pathsep, defpath = _osindex[name]
-               exec 'from %s import *' % name
-               exec 'import %spath' % name
-               exec 'path = %spath' % name
-               exec 'del %spath' % name
-               try:
-                       exec 'from %s import _exit' % name
-               except ImportError:
-                       pass
-               try:
-                       environ
-               except:
-                       environ = {} # Make sure os.environ exists, at least
-               break
+altsep = None
+
+if 'posix' in _names:
+       name = 'posix'
+       curdir = '.'; pardir = '..'; sep = '/'; pathsep = ':'
+       defpath = ':/bin:/usr/bin'
+       from posix import *
+       try:
+               from posix import _exit
+       except ImportError:
+               pass
+       import posixpath
+       path = posixpath
+       del posixpath
+elif 'nt' in _names:
+       name = 'nt'
+       curdir = '.'; pardir = '..'; sep = '\\'; pathsep = ';'
+       defpath = '.;C:\\bin'
+       from nt import *
+       try:
+               from nt import _exit
+       except ImportError:
+               pass
+       import ntpath
+       path = ntpath
+       del ntpath
+elif 'dos' in _names:
+       name = 'dos'
+       curdir = '.'; pardir = '..'; sep = '\\'; pathsep = ';'
+       defpath = '.;C:\\bin'
+       from dos import *
+       try:
+               from dos import _exit
+       except ImportError:
+               pass
+       import dospath
+       path = dospath
+       del dospath
+elif 'mac' in _names:
+       name = 'mac'
+       curdir = ':'; pardir = '::'; sep = ':'; pathsep = '\n'
+       defpath = ':'
+       from mac import *
+       try:
+               from mac import _exit
+       except ImportError:
+               pass
+       import macpath
+       path = macpath
+       del macpath
 else:
-       del name
        raise ImportError, 'no os specific module found'
 
+del _names
+
+# Make sure os.environ exists, at least
+try:
+       environ
+except NameError:
+       environ = {}
+
 def execl(file, *args):
        execv(file, args)
 
@@ -104,31 +137,13 @@ def _execvpe(file, args, env = None):
                                exc, arg = error, (errno, msg)
        raise exc, arg
 
-# Provide listdir for Windows NT that doesn't have it built in
-if name == 'nt':
-       try:
-               _tmp = listdir
-               del _tmp
-       except NameError:
-               def listdir(name):
-                       if path.ismount(name):
-                               list = ['.']
-                       else:
-                               list = ['.', '..']
-                       f = popen('dir/l/b ' + name, 'r')
-                       line = f.readline()
-                       while line:
-                               list.append(line[:-1])
-                               line = f.readline()
-                       return list
-
-
 # Change environ to automatically call putenv() if it exists
 try:
-       _putenv = putenv
+       # This will fail if there's no putenv
+       putenv
 except NameError:
-       _putenv = None
-if _putenv:
+       pass
+else:
        import UserDict
 
        class _Environ(UserDict.UserDict):