diff options
Diffstat (limited to 'Lib/tempfile.py')
| -rw-r--r-- | Lib/tempfile.py | 169 |
1 files changed, 134 insertions, 35 deletions
diff --git a/Lib/tempfile.py b/Lib/tempfile.py index 0537228ba5..ad687b9a03 100644 --- a/Lib/tempfile.py +++ b/Lib/tempfile.py @@ -6,6 +6,14 @@ provided by this module can be used without fear of race conditions except for 'mktemp'. 'mktemp' is subject to race conditions and should not be used; it is provided for backward compatibility only. +The default path names are returned as str. If you supply bytes as +input, all return values will be in bytes. Ex: + + >>> tempfile.mkstemp() + (4, '/tmp/tmptpu9nin8') + >>> tempfile.mkdtemp(suffix=b'') + b'/tmp/tmppbi8f0hy' + This module also provides some data items to the user: TMP_MAX - maximum number of names that will be tried before @@ -21,7 +29,8 @@ __all__ = [ "mkstemp", "mkdtemp", # low level safe interfaces "mktemp", # deprecated unsafe interface "TMP_MAX", "gettempprefix", # constants - "tempdir", "gettempdir" + "tempdir", "gettempdir", + "gettempprefixb", "gettempdirb", ] @@ -55,8 +64,10 @@ if hasattr(_os, 'TMP_MAX'): else: TMP_MAX = 10000 -# Although it does not have an underscore for historical reasons, this -# variable is an internal implementation detail (see issue 10354). +# This variable _was_ unused for legacy reasons, see issue 10354. +# But as of 3.5 we actually use it at runtime so changing it would +# have a possibly desirable side effect... But we do not want to support +# that as an API. It is undocumented on purpose. Do not depend on this. template = "tmp" # Internal routines. @@ -82,6 +93,46 @@ def _exists(fn): else: return True + +def _infer_return_type(*args): + """Look at the type of all args and divine their implied return type.""" + return_type = None + for arg in args: + if arg is None: + continue + if isinstance(arg, bytes): + if return_type is str: + raise TypeError("Can't mix bytes and non-bytes in " + "path components.") + return_type = bytes + else: + if return_type is bytes: + raise TypeError("Can't mix bytes and non-bytes in " + "path components.") + return_type = str + if return_type is None: + return str # tempfile APIs return a str by default. + return return_type + + +def _sanitize_params(prefix, suffix, dir): + """Common parameter processing for most APIs in this module.""" + output_type = _infer_return_type(prefix, suffix, dir) + if suffix is None: + suffix = output_type() + if prefix is None: + if output_type is str: + prefix = template + else: + prefix = _os.fsencode(template) + if dir is None: + if output_type is str: + dir = gettempdir() + else: + dir = gettempdirb() + return prefix, suffix, dir, output_type + + class _RandomNameSequence: """An instance of _RandomNameSequence generates an endless sequence of unpredictable strings which can safely be incorporated @@ -195,17 +246,18 @@ def _get_candidate_names(): return _name_sequence -def _mkstemp_inner(dir, pre, suf, flags): +def _mkstemp_inner(dir, pre, suf, flags, output_type): """Code common to mkstemp, TemporaryFile, and NamedTemporaryFile.""" names = _get_candidate_names() + if output_type is bytes: + names = map(_os.fsencode, names) for seq in range(TMP_MAX): name = next(names) file = _os.path.join(dir, pre + name + suf) try: fd = _os.open(file, flags, 0o600) - return (fd, _os.path.abspath(file)) except FileExistsError: continue # try again except PermissionError: @@ -216,6 +268,7 @@ def _mkstemp_inner(dir, pre, suf, flags): continue else: raise + return (fd, _os.path.abspath(file)) raise FileExistsError(_errno.EEXIST, "No usable temporary file name found") @@ -224,9 +277,13 @@ def _mkstemp_inner(dir, pre, suf, flags): # User visible interfaces. def gettempprefix(): - """Accessor for tempdir.template.""" + """The default prefix for temporary directories.""" return template +def gettempprefixb(): + """The default prefix for temporary directories as bytes.""" + return _os.fsencode(gettempprefix()) + tempdir = None def gettempdir(): @@ -241,24 +298,32 @@ def gettempdir(): _once_lock.release() return tempdir -def mkstemp(suffix="", prefix=template, dir=None, text=False): +def gettempdirb(): + """A bytes version of tempfile.gettempdir().""" + return _os.fsencode(gettempdir()) + +def mkstemp(suffix=None, prefix=None, dir=None, text=False): """User-callable function to create and return a unique temporary file. The return value is a pair (fd, name) where fd is the file descriptor returned by os.open, and name is the filename. - If 'suffix' is specified, the file name will end with that suffix, + If 'suffix' is not None, the file name will end with that suffix, otherwise there will be no suffix. - If 'prefix' is specified, the file name will begin with that prefix, + If 'prefix' is not None, the file name will begin with that prefix, otherwise a default prefix is used. - If 'dir' is specified, the file will be created in that directory, + If 'dir' is not None, the file will be created in that directory, otherwise a default directory is used. If 'text' is specified and true, the file is opened in text mode. Else (the default) the file is opened in binary mode. On some operating systems, this makes no difference. + If any of 'suffix', 'prefix' and 'dir' are not None, they must be the + same type. If they are bytes, the returned name will be bytes; str + otherwise. + The file is readable and writable only by the creating user ID. If the operating system uses permission bits to indicate whether a file is executable, the file is executable by no one. The file @@ -267,18 +332,17 @@ def mkstemp(suffix="", prefix=template, dir=None, text=False): Caller is responsible for deleting the file when done with it. """ - if dir is None: - dir = gettempdir() + prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir) if text: flags = _text_openflags else: flags = _bin_openflags - return _mkstemp_inner(dir, prefix, suffix, flags) + return _mkstemp_inner(dir, prefix, suffix, flags, output_type) -def mkdtemp(suffix="", prefix=template, dir=None): +def mkdtemp(suffix=None, prefix=None, dir=None): """User-callable function to create and return a unique temporary directory. The return value is the pathname of the directory. @@ -291,17 +355,17 @@ def mkdtemp(suffix="", prefix=template, dir=None): Caller is responsible for deleting the directory when done with it. """ - if dir is None: - dir = gettempdir() + prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir) names = _get_candidate_names() + if output_type is bytes: + names = map(_os.fsencode, names) for seq in range(TMP_MAX): name = next(names) file = _os.path.join(dir, prefix + name + suffix) try: _os.mkdir(file, 0o700) - return file except FileExistsError: continue # try again except PermissionError: @@ -312,6 +376,7 @@ def mkdtemp(suffix="", prefix=template, dir=None): continue else: raise + return file raise FileExistsError(_errno.EEXIST, "No usable temporary directory name found") @@ -320,11 +385,12 @@ def mktemp(suffix="", prefix=template, dir=None): """User-callable function to return a unique temporary file name. The file is not created. - Arguments are as for mkstemp, except that the 'text' argument is - not accepted. + Arguments are similar to mkstemp, except that the 'text' argument is + not accepted, and suffix=None, prefix=None and bytes file names are not + supported. - This function is unsafe and should not be used. The file name - refers to a file that did not exist at some point, but by the time + THIS FUNCTION IS UNSAFE AND SHOULD NOT BE USED. The file name may + refer to a file that did not exist at some point, but by the time you get around to creating it, someone else may have beaten you to the punch. """ @@ -454,7 +520,7 @@ class _TemporaryFileWrapper: def NamedTemporaryFile(mode='w+b', buffering=-1, encoding=None, - newline=None, suffix="", prefix=template, + newline=None, suffix=None, prefix=None, dir=None, delete=True): """Create and return a temporary file. Arguments: @@ -467,12 +533,11 @@ def NamedTemporaryFile(mode='w+b', buffering=-1, encoding=None, The file is created as mkstemp() would do it. Returns an object with a file-like interface; the name of the file - is accessible as file.name. The file will be automatically deleted - when it is closed unless the 'delete' argument is set to False. + is accessible as its 'name' attribute. The file will be automatically + deleted when it is closed unless the 'delete' argument is set to False. """ - if dir is None: - dir = gettempdir() + prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir) flags = _bin_openflags @@ -481,13 +546,14 @@ def NamedTemporaryFile(mode='w+b', buffering=-1, encoding=None, if _os.name == 'nt' and delete: flags |= _os.O_TEMPORARY - (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags) + (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags, output_type) try: file = _io.open(fd, mode, buffering=buffering, newline=newline, encoding=encoding) return _TemporaryFileWrapper(file, name, delete) - except Exception: + except BaseException: + _os.unlink(name) _os.close(fd) raise @@ -497,8 +563,13 @@ if _os.name != 'posix' or _os.sys.platform == 'cygwin': TemporaryFile = NamedTemporaryFile else: + # Is the O_TMPFILE flag available and does it work? + # The flag is set to False if os.open(dir, os.O_TMPFILE) raises an + # IsADirectoryError exception + _O_TMPFILE_WORKS = hasattr(_os, 'O_TMPFILE') + def TemporaryFile(mode='w+b', buffering=-1, encoding=None, - newline=None, suffix="", prefix=template, + newline=None, suffix=None, prefix=None, dir=None): """Create and return a temporary file. Arguments: @@ -512,13 +583,41 @@ else: Returns an object with a file-like interface. The file has no name, and will cease to exist when it is closed. """ + global _O_TMPFILE_WORKS - if dir is None: - dir = gettempdir() + prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir) flags = _bin_openflags - - (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags) + if _O_TMPFILE_WORKS: + try: + flags2 = (flags | _os.O_TMPFILE) & ~_os.O_CREAT + fd = _os.open(dir, flags2, 0o600) + except IsADirectoryError: + # Linux kernel older than 3.11 ignores the O_TMPFILE flag: + # O_TMPFILE is read as O_DIRECTORY. Trying to open a directory + # with O_RDWR|O_DIRECTORY fails with IsADirectoryError, a + # directory cannot be open to write. Set flag to False to not + # try again. + _O_TMPFILE_WORKS = False + except OSError: + # The filesystem of the directory does not support O_TMPFILE. + # For example, OSError(95, 'Operation not supported'). + # + # On Linux kernel older than 3.11, trying to open a regular + # file (or a symbolic link to a regular file) with O_TMPFILE + # fails with NotADirectoryError, because O_TMPFILE is read as + # O_DIRECTORY. + pass + else: + try: + return _io.open(fd, mode, buffering=buffering, + newline=newline, encoding=encoding) + except: + _os.close(fd) + raise + # Fallback to _mkstemp_inner(). + + (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags, output_type) try: _os.unlink(name) return _io.open(fd, mode, buffering=buffering, @@ -536,7 +635,7 @@ class SpooledTemporaryFile: def __init__(self, max_size=0, mode='w+b', buffering=-1, encoding=None, newline=None, - suffix="", prefix=template, dir=None): + suffix=None, prefix=None, dir=None): if 'b' in mode: self._file = _io.BytesIO() else: @@ -687,7 +786,7 @@ class TemporaryDirectory(object): in it are removed. """ - def __init__(self, suffix="", prefix=template, dir=None): + def __init__(self, suffix=None, prefix=None, dir=None): self.name = mkdtemp(suffix, prefix, dir) self._finalizer = _weakref.finalize( self, self._cleanup, self.name, |