| 1 | """Extended file operations available in POSIX.
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| 2 |
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| 3 | f = posixfile.open(filename, [mode, [bufsize]])
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| 4 | will create a new posixfile object
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| 5 |
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| 6 | f = posixfile.fileopen(fileobject)
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| 7 | will create a posixfile object from a builtin file object
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| 8 |
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| 9 | f.file()
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| 10 | will return the original builtin file object
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| 11 |
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| 12 | f.dup()
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| 13 | will return a new file object based on a new filedescriptor
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| 14 |
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| 15 | f.dup2(fd)
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| 16 | will return a new file object based on the given filedescriptor
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| 17 |
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| 18 | f.flags(mode)
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| 19 | will turn on the associated flag (merge)
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| 20 | mode can contain the following characters:
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| 21 |
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| 22 | (character representing a flag)
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| 23 | a append only flag
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| 24 | c close on exec flag
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| 25 | n no delay flag
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| 26 | s synchronization flag
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| 27 | (modifiers)
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| 28 | ! turn flags 'off' instead of default 'on'
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| 29 | = copy flags 'as is' instead of default 'merge'
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| 30 | ? return a string in which the characters represent the flags
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| 31 | that are set
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| 32 |
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| 33 | note: - the '!' and '=' modifiers are mutually exclusive.
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| 34 | - the '?' modifier will return the status of the flags after they
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| 35 | have been changed by other characters in the mode string
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| 36 |
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| 37 | f.lock(mode [, len [, start [, whence]]])
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| 38 | will (un)lock a region
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| 39 | mode can contain the following characters:
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| 40 |
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| 41 | (character representing type of lock)
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| 42 | u unlock
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| 43 | r read lock
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| 44 | w write lock
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| 45 | (modifiers)
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| 46 | | wait until the lock can be granted
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| 47 | ? return the first lock conflicting with the requested lock
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| 48 | or 'None' if there is no conflict. The lock returned is in the
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| 49 | format (mode, len, start, whence, pid) where mode is a
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| 50 | character representing the type of lock ('r' or 'w')
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| 51 |
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| 52 | note: - the '?' modifier prevents a region from being locked; it is
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| 53 | query only
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| 54 | """
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| 55 |
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| 56 |
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| 57 | class _posixfile_:
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| 58 | """File wrapper class that provides extra POSIX file routines."""
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| 59 |
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| 60 | states = ['open', 'closed']
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| 61 |
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| 62 | #
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| 63 | # Internal routines
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| 64 | #
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| 65 | def __repr__(self):
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| 66 | file = self._file_
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| 67 | return "<%s posixfile '%s', mode '%s' at %s>" % \
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| 68 | (self.states[file.closed], file.name, file.mode, \
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| 69 | hex(id(self))[2:])
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| 70 |
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| 71 | #
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| 72 | # Initialization routines
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| 73 | #
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| 74 | def open(self, name, mode='r', bufsize=-1):
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| 75 | import __builtin__
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| 76 | return self.fileopen(__builtin__.open(name, mode, bufsize))
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| 77 |
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| 78 | def fileopen(self, file):
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| 79 | import types
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| 80 | if repr(type(file)) != "<type 'file'>":
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| 81 | raise TypeError, 'posixfile.fileopen() arg must be file object'
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| 82 | self._file_ = file
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| 83 | # Copy basic file methods
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| 84 | for maybemethod in dir(file):
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| 85 | if not maybemethod.startswith('_'):
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| 86 | attr = getattr(file, maybemethod)
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| 87 | if isinstance(attr, types.BuiltinMethodType):
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| 88 | setattr(self, maybemethod, attr)
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| 89 | return self
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| 90 |
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| 91 | #
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| 92 | # New methods
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| 93 | #
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| 94 | def file(self):
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| 95 | return self._file_
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| 96 |
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| 97 | def dup(self):
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| 98 | import posix
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| 99 |
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| 100 | if not hasattr(posix, 'fdopen'):
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| 101 | raise AttributeError, 'dup() method unavailable'
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| 102 |
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| 103 | return posix.fdopen(posix.dup(self._file_.fileno()), self._file_.mode)
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| 104 |
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