cpython/Lib/os.py

143 lines
3.4 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 ':')
# - 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).
_osindex = {
'posix': ('.', '..', '/', ':', ':/bin:/usr/bin'),
'dos': ('.', '..', '\\', ';', '.;C:\\bin'),
'nt': ('.', '..', '\\', ';', '.;C:\\bin'),
'mac': (':', '::', ':', '\n', ':'),
}
# For freeze.py script:
if 0:
import posix
import posixpath
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
else:
del name
raise ImportError, 'no os specific module found'
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
# 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
except NameError:
_putenv = None
if _putenv:
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)