msvcrt --- MS VC++ runtime 提供的有用例程


These functions provide access to some useful capabilities on Windows platforms.Some higher-level modules use these functions to build the Windowsimplementations of their services. For example, thegetpass module usesthis in the implementation of thegetpass() function.

Further documentation on these functions can be found in the Platform APIdocumentation.

The module implements both the normal and wide char variants of the console I/Oapi. The normal API deals only with ASCII characters and is of limited usefor internationalized applications. The wide char API should be used whereever possible.

在 3.3 版的變更:Operations in this module now raiseOSError whereIOErrorwas raised.

File Operations

msvcrt.locking(fd,mode,nbytes)

Lock part of a file based on file descriptorfd from the C runtime. RaisesOSError on failure. The locked region of the file extends from thecurrent file position fornbytes bytes, and may continue beyond the end of thefile.mode must be one of theLK_* constants listed below. Multipleregions in a file may be locked at the same time, but may not overlap. Adjacentregions are not merged; they must be unlocked individually.

引發一個附帶引數fdmodenbytes稽核事件msvcrt.locking

msvcrt.LK_LOCK
msvcrt.LK_RLCK

Locks the specified bytes. If the bytes cannot be locked, the programimmediately tries again after 1 second. If, after 10 attempts, the bytes cannotbe locked,OSError is raised.

msvcrt.LK_NBLCK
msvcrt.LK_NBRLCK

Locks the specified bytes. If the bytes cannot be locked,OSError israised.

msvcrt.LK_UNLCK

Unlocks the specified bytes, which must have been previously locked.

msvcrt.setmode(fd,flags)

Set the line-end translation mode for the file descriptorfd. To set it totext mode,flags should beos.O_TEXT; for binary, it should beos.O_BINARY.

msvcrt.open_osfhandle(handle,flags)

Create a C runtime file descriptor from the file handlehandle. Theflagsparameter should be a bitwise OR ofos.O_APPEND,os.O_RDONLY,os.O_TEXT andos.O_NOINHERIT.The returned file descriptor may be used as a parametertoos.fdopen() to create a file object.

The file descriptor is inheritable by default. Passos.O_NOINHERITflag to make it non inheritable.

引發一個附帶引數handleflags稽核事件msvcrt.open_osfhandle

msvcrt.get_osfhandle(fd)

Return the file handle for the file descriptorfd. RaisesOSError iffd is not recognized.

引發一個附帶引數fd稽核事件msvcrt.get_osfhandle

Console I/O

msvcrt.kbhit()

Returns a nonzero value if a keypress is waiting to be read. Otherwise,return 0.

msvcrt.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 keypressis not already available, but will not wait forEnter to bepressed. If the pressed key was a special function key, this willreturn'\000' or'\xe0'; the next call will return the keycode.TheControl-C keypress cannot be read with this function.

msvcrt.getwch()

Wide char variant ofgetch(), returning a Unicode value.

msvcrt.getche()

Similar togetch(), but the keypress will be echoed if it represents aprintable character.

msvcrt.getwche()

Wide char variant ofgetche(), returning a Unicode value.

msvcrt.putch(char)

Print the byte stringchar to the console without buffering.

msvcrt.putwch(unicode_char)

Wide char variant ofputch(), accepting a Unicode value.

msvcrt.ungetch(char)

Cause the byte stringchar to be "pushed back" into the console buffer;it will be the next character read bygetch() orgetche().

msvcrt.ungetwch(unicode_char)

Wide char variant ofungetch(), accepting a Unicode value.

Other Functions

msvcrt.heapmin()

Force themalloc() heap to clean itself up and return unused blocks tothe operating system. On failure, this raisesOSError.

msvcrt.set_error_mode(mode)

Changes the location where the C runtime writes an error message for an errorthat might end the program.mode must be one of theOUT_*constants listed below orREPORT_ERRMODE. Returns the old settingor -1 if an error occurs. Only available indebug build of Python.

msvcrt.OUT_TO_DEFAULT

Error sink is determined by the app's type. Only available indebug build of Python.

msvcrt.OUT_TO_STDERR

Error sink is a standard error. Only available indebug build of Python.

msvcrt.OUT_TO_MSGBOX

Error sink is a message box. Only available indebug build of Python.

msvcrt.REPORT_ERRMODE

Report the current error mode value. Only available indebug build of Python.

msvcrt.CrtSetReportMode(type,mode)

Specifies the destination or destinations for a specific report typegenerated by_CrtDbgReport() in the MS VC++ runtime.type must beone of theCRT_* constants listed below.mode must be one of theCRTDBG_* constants listed below. Only available indebug build of Python.

msvcrt.CrtSetReportFile(type,file)

After you useCrtSetReportMode() to specifyCRTDBG_MODE_FILE,you can specify the file handle to receive the message text.type must beone of theCRT_* constants listed below.file should be the filehandle your want specified. Only available indebug build of Python.

msvcrt.CRT_WARN

Warnings, messages, and information that doesn't need immediate attention.

msvcrt.CRT_ERROR

Errors, unrecoverable problems, and issues that require immediate attention.

msvcrt.CRT_ASSERT

Assertion failures.

msvcrt.CRTDBG_MODE_DEBUG

Writes the message to the debugger's output window.

msvcrt.CRTDBG_MODE_FILE

Writes the message to a user-supplied file handle.CrtSetReportFile()should be called to define the specific file or stream to use asthe destination.

msvcrt.CRTDBG_MODE_WNDW

Creates a message box to display the message along with theAbort,Retry, andIgnore buttons.

msvcrt.CRTDBG_REPORT_MODE

Returns currentmode for the specifiedtype.

msvcrt.CRT_ASSEMBLY_VERSION

The CRT Assembly version, from thecrtassem.h header file.

msvcrt.VC_ASSEMBLY_PUBLICKEYTOKEN

The VC Assembly public key token, from thecrtassem.h header file.

msvcrt.LIBRARIES_ASSEMBLY_NAME_PREFIX

The Libraries Assembly name prefix, from thecrtassem.h header file.