161 lines
4.5 KiB
ReStructuredText
161 lines
4.5 KiB
ReStructuredText
:mod:`msvcrt` --- Useful routines from the MS VC++ runtime
|
|
==========================================================
|
|
|
|
.. module:: msvcrt
|
|
:platform: Windows
|
|
:synopsis: Miscellaneous useful routines from the MS VC++ runtime.
|
|
|
|
.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
|
|
|
|
--------------
|
|
|
|
These functions provide access to some useful capabilities on Windows platforms.
|
|
Some higher-level modules use these functions to build the Windows
|
|
implementations of their services. For example, the :mod:`getpass` module uses
|
|
this in the implementation of the :func:`getpass` function.
|
|
|
|
Further documentation on these functions can be found in the Platform API
|
|
documentation.
|
|
|
|
The module implements both the normal and wide char variants of the console I/O
|
|
api. The normal API deals only with ASCII characters and is of limited use
|
|
for internationalized applications. The wide char API should be used where
|
|
ever possible.
|
|
|
|
.. versionchanged:: 3.3
|
|
Operations in this module now raise :exc:`OSError` where :exc:`IOError`
|
|
was raised.
|
|
|
|
|
|
.. _msvcrt-files:
|
|
|
|
File Operations
|
|
---------------
|
|
|
|
|
|
.. function:: locking(fd, mode, nbytes)
|
|
|
|
Lock part of a file based on file descriptor *fd* from the C runtime. Raises
|
|
:exc:`OSError` on failure. The locked region of the file extends from the
|
|
current file position for *nbytes* bytes, and may continue beyond the end of the
|
|
file. *mode* must be one of the :const:`LK_\*` constants listed below. Multiple
|
|
regions in a file may be locked at the same time, but may not overlap. Adjacent
|
|
regions are not merged; they must be unlocked individually.
|
|
|
|
.. audit-event:: msvcrt.locking fd,mode,nbytes msvcrt.locking
|
|
|
|
|
|
.. data:: LK_LOCK
|
|
LK_RLCK
|
|
|
|
Locks the specified bytes. If the bytes cannot be locked, the program
|
|
immediately tries again after 1 second. If, after 10 attempts, the bytes cannot
|
|
be locked, :exc:`OSError` is raised.
|
|
|
|
|
|
.. data:: LK_NBLCK
|
|
LK_NBRLCK
|
|
|
|
Locks the specified bytes. If the bytes cannot be locked, :exc:`OSError` is
|
|
raised.
|
|
|
|
|
|
.. data:: LK_UNLCK
|
|
|
|
Unlocks the specified bytes, which must have been previously locked.
|
|
|
|
|
|
.. function:: setmode(fd, flags)
|
|
|
|
Set the line-end translation mode for the file descriptor *fd*. To set it to
|
|
text mode, *flags* should be :const:`os.O_TEXT`; for binary, it should be
|
|
:const:`os.O_BINARY`.
|
|
|
|
|
|
.. function:: open_osfhandle(handle, flags)
|
|
|
|
Create a C runtime file descriptor from the file handle *handle*. The *flags*
|
|
parameter should be a bitwise OR of :const:`os.O_APPEND`, :const:`os.O_RDONLY`,
|
|
and :const:`os.O_TEXT`. The returned file descriptor may be used as a parameter
|
|
to :func:`os.fdopen` to create a file object.
|
|
|
|
.. audit-event:: msvcrt.open_osfhandle handle,flags msvcrt.open_osfhandle
|
|
|
|
|
|
.. function:: get_osfhandle(fd)
|
|
|
|
Return the file handle for the file descriptor *fd*. Raises :exc:`OSError` if
|
|
*fd* is not recognized.
|
|
|
|
.. audit-event:: msvcrt.get_osfhandle fd msvcrt.get_osfhandle
|
|
|
|
|
|
.. _msvcrt-console:
|
|
|
|
Console I/O
|
|
-----------
|
|
|
|
|
|
.. function:: kbhit()
|
|
|
|
Return ``True`` if a keypress is waiting to be read.
|
|
|
|
|
|
.. function:: getch()
|
|
|
|
Read a keypress and return the resulting character as a byte string.
|
|
Nothing is echoed to the console. This call will block if a keypress
|
|
is not already available, but will not wait for :kbd:`Enter` to be
|
|
pressed. If the pressed key was a special function key, this will
|
|
return ``'\000'`` or ``'\xe0'``; the next call will return the keycode.
|
|
The :kbd:`Control-C` keypress cannot be read with this function.
|
|
|
|
|
|
.. function:: getwch()
|
|
|
|
Wide char variant of :func:`getch`, returning a Unicode value.
|
|
|
|
|
|
.. function:: getche()
|
|
|
|
Similar to :func:`getch`, but the keypress will be echoed if it represents a
|
|
printable character.
|
|
|
|
|
|
.. function:: getwche()
|
|
|
|
Wide char variant of :func:`getche`, returning a Unicode value.
|
|
|
|
|
|
.. function:: putch(char)
|
|
|
|
Print the byte string *char* to the console without buffering.
|
|
|
|
|
|
.. function:: putwch(unicode_char)
|
|
|
|
Wide char variant of :func:`putch`, accepting a Unicode value.
|
|
|
|
|
|
.. function:: ungetch(char)
|
|
|
|
Cause the byte string *char* to be "pushed back" into the console buffer;
|
|
it will be the next character read by :func:`getch` or :func:`getche`.
|
|
|
|
|
|
.. function:: ungetwch(unicode_char)
|
|
|
|
Wide char variant of :func:`ungetch`, accepting a Unicode value.
|
|
|
|
|
|
.. _msvcrt-other:
|
|
|
|
Other Functions
|
|
---------------
|
|
|
|
|
|
.. function:: heapmin()
|
|
|
|
Force the :c:func:`malloc` heap to clean itself up and return unused blocks to
|
|
the operating system. On failure, this raises :exc:`OSError`.
|