symbian-qemu-0.9.1-12/python-2.6.1/Doc/c-api/file.rst
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Doc/c-api/file.rst	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,168 @@
+.. highlightlang:: c
+
+.. _fileobjects:
+
+File Objects
+------------
+
+.. index:: object: file
+
+Python's built-in file objects are implemented entirely on the :ctype:`FILE\*`
+support from the C standard library.  This is an implementation detail and may
+change in future releases of Python.
+
+
+.. ctype:: PyFileObject
+
+   This subtype of :ctype:`PyObject` represents a Python file object.
+
+
+.. cvar:: PyTypeObject PyFile_Type
+
+   .. index:: single: FileType (in module types)
+
+   This instance of :ctype:`PyTypeObject` represents the Python file type.  This is
+   exposed to Python programs as ``file`` and ``types.FileType``.
+
+
+.. cfunction:: int PyFile_Check(PyObject *p)
+
+   Return true if its argument is a :ctype:`PyFileObject` or a subtype of
+   :ctype:`PyFileObject`.
+
+   .. versionchanged:: 2.2
+      Allowed subtypes to be accepted.
+
+
+.. cfunction:: int PyFile_CheckExact(PyObject *p)
+
+   Return true if its argument is a :ctype:`PyFileObject`, but not a subtype of
+   :ctype:`PyFileObject`.
+
+   .. versionadded:: 2.2
+
+
+.. cfunction:: PyObject* PyFile_FromString(char *filename, char *mode)
+
+   .. index:: single: fopen()
+
+   On success, return a new file object that is opened on the file given by
+   *filename*, with a file mode given by *mode*, where *mode* has the same
+   semantics as the standard C routine :cfunc:`fopen`.  On failure, return *NULL*.
+
+
+.. cfunction:: PyObject* PyFile_FromFile(FILE *fp, char *name, char *mode, int (*close)(FILE*))
+
+   Create a new :ctype:`PyFileObject` from the already-open standard C file
+   pointer, *fp*.  The function *close* will be called when the file should be
+   closed.  Return *NULL* on failure.
+
+
+.. cfunction:: FILE* PyFile_AsFile(PyObject \*p)
+
+   Return the file object associated with *p* as a :ctype:`FILE\*`.
+
+   If the caller will ever use the returned :ctype:`FILE\*` object while
+   the GIL is released it must also call the `PyFile_IncUseCount` and
+   `PyFile_DecUseCount` functions described below as appropriate.
+
+
+.. cfunction:: void PyFile_IncUseCount(PyFileObject \*p)
+
+   Increments the PyFileObject's internal use count to indicate
+   that the underlying :ctype:`FILE\*` is being used.
+   This prevents Python from calling f_close() on it from another thread.
+   Callers of this must call `PyFile_DecUseCount` when they are
+   finished with the :ctype:`FILE\*`.  Otherwise the file object will
+   never be closed by Python.
+
+   The GIL must be held while calling this function.
+
+   The suggested use is to call this after `PyFile_AsFile` just before
+   you release the GIL.
+
+   .. versionadded:: 2.6
+
+
+.. cfunction:: void PyFile_DecUseCount(PyFileObject \*p)
+
+   Decrements the PyFileObject's internal unlocked_count member to
+   indicate that the caller is done with its own use of the :ctype:`FILE\*`.
+   This may only be called to undo a prior call to `PyFile_IncUseCount`.
+
+   The GIL must be held while calling this function.
+
+   .. versionadded:: 2.6
+
+
+.. cfunction:: PyObject* PyFile_GetLine(PyObject *p, int n)
+
+   .. index:: single: EOFError (built-in exception)
+
+   Equivalent to ``p.readline([n])``, this function reads one line from the
+   object *p*.  *p* may be a file object or any object with a :meth:`readline`
+   method.  If *n* is ``0``, exactly one line is read, regardless of the length of
+   the line.  If *n* is greater than ``0``, no more than *n* bytes will be read
+   from the file; a partial line can be returned.  In both cases, an empty string
+   is returned if the end of the file is reached immediately.  If *n* is less than
+   ``0``, however, one line is read regardless of length, but :exc:`EOFError` is
+   raised if the end of the file is reached immediately.
+
+
+.. cfunction:: PyObject* PyFile_Name(PyObject *p)
+
+   Return the name of the file specified by *p* as a string object.
+
+
+.. cfunction:: void PyFile_SetBufSize(PyFileObject *p, int n)
+
+   .. index:: single: setvbuf()
+
+   Available on systems with :cfunc:`setvbuf` only.  This should only be called
+   immediately after file object creation.
+
+
+.. cfunction:: int PyFile_SetEncoding(PyFileObject *p, const char *enc)
+
+   Set the file's encoding for Unicode output to *enc*. Return 1 on success and 0
+   on failure.
+
+   .. versionadded:: 2.3
+
+
+.. cfunction:: int PyFile_SetEncodingAndErrors(PyFileObject *p, const char *enc, *errors)
+
+   Set the file's encoding for Unicode output to *enc*, and its error
+   mode to *err*. Return 1 on success and 0 on failure.
+
+   .. versionadded:: 2.6
+
+
+.. cfunction:: int PyFile_SoftSpace(PyObject *p, int newflag)
+
+   .. index:: single: softspace (file attribute)
+
+   This function exists for internal use by the interpreter.  Set the
+   :attr:`softspace` attribute of *p* to *newflag* and return the previous value.
+   *p* does not have to be a file object for this function to work properly; any
+   object is supported (thought its only interesting if the :attr:`softspace`
+   attribute can be set).  This function clears any errors, and will return ``0``
+   as the previous value if the attribute either does not exist or if there were
+   errors in retrieving it.  There is no way to detect errors from this function,
+   but doing so should not be needed.
+
+
+.. cfunction:: int PyFile_WriteObject(PyObject *obj, PyObject *p, int flags)
+
+   .. index:: single: Py_PRINT_RAW
+
+   Write object *obj* to file object *p*.  The only supported flag for *flags* is
+   :const:`Py_PRINT_RAW`; if given, the :func:`str` of the object is written
+   instead of the :func:`repr`.  Return ``0`` on success or ``-1`` on failure; the
+   appropriate exception will be set.
+
+
+.. cfunction:: int PyFile_WriteString(const char *s, PyObject *p)
+
+   Write string *s* to file object *p*.  Return ``0`` on success or ``-1`` on
+   failure; the appropriate exception will be set.