Lib/os.py

   1 # os.py -- either mac or posix depending on what system we're on.
   2
   3 # This exports:
   4 # - all functions from either posix or mac, e.g., os.unlink, os.stat, etc.
   5 # - os.path is either module posixpath or macpath
   6 # - os.name is either 'posix' or 'mac'
   7 # - os.curdir is a string representing the current directory ('.' or ':')
   8 # - os.pardir is a string representing the parent directory ('..' or '::')
   9 # - os.sep is the (or a most common) pathname separator ('/' or ':')
  10
  11 # Programs that import and use 'os' stand a better chance of being
  12 # portable between different platforms.  Of course, they must then
  13 # only use functions that are defined by all platforms (e.g., unlink
  14 # and opendir), and leave all pathname manipulation to os.path
  15 # (e.g., split and join).
  16
  17 # XXX This will need to distinguish between real posix and MS-DOS emulation
  18
  19 try:
  20         from posix import *
  21         try:
  22                 from posix import _exit
  23         except ImportError:
  24                 pass
  25         name = 'posix'
  26         curdir = '.'
  27         pardir = '..'
  28         sep = '/'
  29         import posixpath
  30         path = posixpath
  31         del posixpath
  32 except ImportError:
  33         from mac import *
  34         name = 'mac'
  35         curdir = ':'
  36         pardir = '::'
  37         sep = ':'
  38         import macpath
  39         path = macpath
  40         del macpath
  41
  42 def execl(file, *args):
  43         execv(file, args)
  44
  45 def execle(file, *args):
  46         env = args[-1]
  47         execve(file, args[:-1], env)
  48
  49 def execlp(file, *args):
  50         execvp(file, args)
  51
  52 def execvp(file, args):
  53         if '/' in file:
  54                 execv(file, args)
  55                 return
  56         ENOENT = 2
  57         if environ.has_key('PATH'):
  58                 import string
  59                 PATH = string.splitfields(environ['PATH'], ':')
  60         else:
  61                 PATH = ['', '/bin', '/usr/bin']
  62         exc, arg = (ENOENT, 'No such file or directory')
  63         for dir in PATH:
  64                 fullname = path.join(dir, file)
  65                 try:
  66                         execv(fullname, args)
  67                 except error, (errno, msg):
  68                         if errno != ENOENT:
  69                                 exc, arg = error, (errno, msg)
  70         raise exc, arg