cpython/Lib/os.py
Guido van Rossum a28dab5ea2 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...
1997-08-29 22:36:47 +00:00

158 lines
3.6 KiB
Python

# os.py -- either mac, dos or posix depending on what system we're on.
# This exports:
# - all functions from either posix or mac, e.g., os.unlink, os.stat, etc.
# - os.path is either module posixpath or macpath
# - 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 ':' 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
# Programs that import and use 'os' stand a better chance of being
# portable between different platforms. Of course, they must then
# only use functions that are defined by all platforms (e.g., unlink
# and opendir), and leave all pathname manipulation to os.path
# (e.g., split and join).
import sys
_names = sys.builtin_module_names
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:
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)
def execle(file, *args):
env = args[-1]
execve(file, args[:-1], env)
def execlp(file, *args):
execvp(file, args)
def execlpe(file, *args):
env = args[-1]
execvpe(file, args[:-1], env)
def execvp(file, args):
_execvpe(file, args)
def execvpe(file, args, env):
_execvpe(file, args, env)
_notfound = None
def _execvpe(file, args, env = None):
if env:
func = execve
argrest = (args, env)
else:
func = execv
argrest = (args,)
env = environ
global _notfound
head, tail = path.split(file)
if head:
apply(func, (file,) + argrest)
return
if env.has_key('PATH'):
envpath = env['PATH']
else:
envpath = defpath
import string
PATH = string.splitfields(envpath, pathsep)
if not _notfound:
import tempfile
# Exec a file that is guaranteed not to exist
try: execv(tempfile.mktemp(), ())
except error, _notfound: pass
exc, arg = error, _notfound
for dir in PATH:
fullname = path.join(dir, file)
try:
apply(func, (fullname,) + argrest)
except error, (errno, msg):
if errno != arg[0]:
exc, arg = error, (errno, msg)
raise exc, arg
# Change environ to automatically call putenv() if it exists
try:
# This will fail if there's no putenv
putenv
except NameError:
pass
else:
import UserDict
class _Environ(UserDict.UserDict):
def __init__(self, environ):
UserDict.UserDict.__init__(self)
self.data = environ
def __setitem__(self, key, item):
putenv(key, item)
self.data[key] = item
environ = _Environ(environ)