summaryrefslogtreecommitdiffstats
path: root/Lib/os.py
blob: c7a3cc5a57b178a1c82d8eaf41169000ff6b67b5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
"""OS routines for Mac, DOS, NT, or Posix depending on what system we're on.

This exports:
  - all functions from posix, nt, dos, os2, mac, or ce, e.g. unlink, stat, etc.
  - os.path is one of the modules posixpath, ntpath, macpath, or dospath
  - os.name is 'posix', 'nt', 'dos', 'os2', 'mac', or 'ce'
  - 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 alternate pathname separator (None or '/')
  - os.pathsep is the component separator used in $PATH etc
  - os.linesep is the line separator in text files ('\r' or '\n' or '\r\n')
  - 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'
    linesep = '\n'
    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'
    linesep = '\r\n'
    curdir = '.'; pardir = '..'; sep = '\\'; pathsep = ';'
    defpath = '.;C:\\bin'
    from nt import *
    for i in ['_exit']:
        try:
            exec "from nt import " + i
        except ImportError:
            pass
    import ntpath
    path = ntpath
    del ntpath
elif 'dos' in _names:
    name = 'dos'
    linesep = '\r\n'
    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 'os2' in _names:
    name = 'os2'
    linesep = '\r\n'
    curdir = '.'; pardir = '..'; sep = '\\'; pathsep = ';'
    defpath = '.;C:\\bin'
    from os2 import *
    try:
        from os2 import _exit
    except ImportError:
        pass
    import ntpath
    path = ntpath
    del ntpath
elif 'mac' in _names:
    name = 'mac'
    linesep = '\r'
    curdir = ':'; pardir = '::'; sep = ':'; pathsep = '\n'
    defpath = ':'
    from mac import *
    try:
        from mac import _exit
    except ImportError:
        pass
    import macpath
    path = macpath
    del macpath
elif 'ce' in _names:
    name = 'ce'
    linesep = '\r\n'
    curdir = '.'; pardir = '..'; sep = '\\'; pathsep = ';'
    defpath = '\\Windows'
    from ce import *
    for i in ['_exit']:
        try:
            exec "from ce import " + i
        except ImportError:
            pass
    # We can use the standard Windows path.
    import ntpath
    path = ntpath
    del ntpath
else:
    raise ImportError, 'no os specific module found'

del _names

sys.modules['os.path'] = path

# Super directory utilities.
# (Inspired by Eric Raymond; the doc strings are mostly his)

def makedirs(name, mode=0777):
    """makedirs(path [, mode=0777]) -> None

    Super-mkdir; create a leaf directory and all intermediate ones.
    Works like mkdir, except that any intermediate path segment (not
    just the rightmost) will be created if it does not exist.  This is
    recursive.

    """
    head, tail = path.split(name)
    if head and tail and not path.exists(head):
        makedirs(head, mode)
    mkdir(name, mode)

def removedirs(name):
    """removedirs(path) -> None

    Super-rmdir; remove a leaf directory and empty all intermediate
    ones.  Works like rmdir except that, if the leaf directory is
    successfully removed, directories corresponding to rightmost path
    segments will be pruned way until either the whole path is
    consumed or an error occurs.  Errors during this latter phase are
    ignored -- they generally mean that a directory was not empty.

    """
    rmdir(name)
    head, tail = path.split(name)
    while head and tail:
        try:
            rmdir(head)
        except error:
            break
        head, tail = path.split(head)

def renames(old, new):
    """renames(old, new) -> None

    Super-rename; create directories as necessary and delete any left
    empty.  Works like rename, except creation of any intermediate
    directories needed to make the new pathname good is attempted
    first.  After the rename, directories corresponding to rightmost
    path segments of the old name will be pruned way until either the
    whole path is consumed or a nonempty directory is found.

    Note: this function can fail with the new directory structure made
    if you lack permissions needed to unlink the leaf directory or
    file.

    """
    head, tail = path.split(new)
    if head and tail and not path.exists(head):
        makedirs(head)
    rename(old, new)
    head, tail = path.split(old)
    if head and tail:
        try:
            removedirs(head)
        except error:
            pass

# Make sure os.environ exists, at least
try:
    environ
except NameError:
    environ = {}

def execl(file, *args):
    """execl(file, *args)

    Execute the executable file with argument list args, replacing the
    current process. """
    execv(file, args)

def execle(file, *args):
    """execle(file, *args, env)

    Execute the executable file with argument list args and
    environment env, replacing the current process. """
    env = args[-1]
    execve(file, args[:-1], env)

def execlp(file, *args):
    """execlp(file, *args)

    Execute the executable file (which is searched for along $PATH)
    with argument list args, replacing the current process. """
    execvp(file, args)

def execlpe(file, *args):
    """execlpe(file, *args, env)

    Execute the executable file (which is searched for along $PATH)
    with argument list args and environment env, replacing the current
    process. """    
    env = args[-1]
    execvpe(file, args[:-1], env)

def execvp(file, args):
    """execp(file, args)

    Execute the executable file (which is searched for along $PATH)
    with argument list args, replacing the current process.
    args may be a list or tupe of strings. """
    _execvpe(file, args)

def execvpe(file, args, env):
    """execv(file, args, env)

    Execute the executable file (which is searched for along $PATH)
    with argument list args and environment env , replacing the
    current process.
    args may be a list or tupe of strings. """    
    _execvpe(file, args, env)

_notfound = None
def _execvpe(file, args, env=None):
    if env is not None:
        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
    PATH = envpath.split(pathsep)
    if not _notfound:
        import tempfile
        # Exec a file that is guaranteed not to exist
        try: execv(tempfile.mktemp(), ('blah',))
        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

    if name in ('os2', 'nt', 'dos'):  # Where Env Var Names Must Be UPPERCASE
        # But we store them as upper case
        class _Environ(UserDict.UserDict):
            def __init__(self, environ):
                UserDict.UserDict.__init__(self)
                data = self.data
                for k, v in environ.items():
                    data[k.upper()] = v
            def __setitem__(self, key, item):
                putenv(key, item)
                self.data[key.upper()] = item
            def __getitem__(self, key):
                return self.data[key.upper()]
            def __delitem__(self, key):
                del self.data[key.upper()]
            def has_key(self, key):
                return self.data.has_key(key.upper())
            def get(self, key, failobj=None):
                return self.data.get(key.upper(), failobj)
            def update(self, dict):
                for k, v in dict.items():
                    self[k] = v

    else:  # Where Env Var Names Can Be Mixed Case
        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
            def update(self, dict):
                for k, v in dict.items():
                    self[k] = v

    environ = _Environ(environ)

def getenv(key, default=None):
    """Get an environment variable, return None if it doesn't exist.

    The optional second argument can specify an alternative default."""
    return environ.get(key, default)

def _exists(name):
    try:
        eval(name)
        return 1
    except NameError:
        return 0

# Supply spawn*() (probably only for Unix)
if _exists("fork") and not _exists("spawnv") and _exists("execv"):

    P_WAIT = 0
    P_NOWAIT = P_NOWAITO = 1

    # XXX Should we support P_DETACH?  I suppose it could fork()**2
    # and close the std I/O streams.  Also, P_OVERLAY is the same
    # as execv*()?

    def _spawnvef(mode, file, args, env, func):
        # Internal helper; func is the exec*() function to use
        pid = fork()
        if not pid:
            # Child
            try:
                if env is None:
                    func(file, args)
                else:
                    func(file, args, env)
            except:
                _exit(127)
        else:
            # Parent
            if mode == P_NOWAIT:
                return pid # Caller is responsible for waiting!
            while 1:
                wpid, sts = waitpid(pid, 0)
                if WIFSTOPPED(sts):
                    continue
                elif WIFSIGNALED(sts):
                    return -WTERMSIG(sts)
                elif WIFEXITED(sts):
                    return WEXITSTATUS(sts)
                else:
                    raise error, "Not stopped, signaled or exited???"

    def spawnv(mode, file, args):
        """spawnv(mode, file, args) -> integer

Execute file with arguments from args in a subprocess.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it. """   
        return _spawnvef(mode, file, args, None, execv)

    def spawnve(mode, file, args, env):
        """spawnve(mode, file, args, env) -> integer

Execute file with arguments from args in a subprocess with the
specified environment.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it. """
        return _spawnvef(mode, file, args, env, execve)

    # Note: spawnvp[e] is't currently supported on Windows

    def spawnvp(mode, file, args):
        """spawnvp(mode, file, args) -> integer

Execute file (which is looked for along $PATH) with arguments from
args in a subprocess.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it. """
        return _spawnvef(mode, file, args, None, execvp)

    def spawnvpe(mode, file, args, env):
        """spawnvpe(mode, file, args, env) -> integer

Execute file (which is looked for along $PATH) with arguments from
args in a subprocess with the supplied environment.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it. """
        return _spawnvef(mode, file, args, env, execvpe)

if _exists("spawnv"):
    # These aren't supplied by the basic Windows code
    # but can be easily implemented in Python

    def spawnl(mode, file, *args):
        """spawnl(mode, file, *args) -> integer

Execute file with arguments from args in a subprocess.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it. """
        return spawnv(mode, file, args)

    def spawnle(mode, file, *args):
        """spawnle(mode, file, *args, env) -> integer

Execute file with arguments from args in a subprocess with the
supplied environment.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it. """
        env = args[-1]
        return spawnve(mode, file, args[:-1], env)

if _exists("spawnvp"):
    # At the moment, Windows doesn't implement spawnvp[e],
    # so it won't have spawnlp[e] either.
    def spawnlp(mode, file, *args):
        """spawnlp(mode, file, *args, env) -> integer

Execute file (which is looked for along $PATH) with arguments from
args in a subprocess with the supplied environment.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it. """
        return spawnvp(mode, file, args)

    def spawnlpe(mode, file, *args):
        """spawnlpe(mode, file, *args, env) -> integer

Execute file (which is looked for along $PATH) with arguments from
args in a subprocess with the supplied environment.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it. """
        env = args[-1]
        return spawnvpe(mode, file, args[:-1], env)