Windows 上的符号链接？

Question

有谁知道如何从 Python 跨 win32 版本创建/读取符号链接？理想情况下，应该有最少量的平台特定代码，因为我需要我的应用程序是跨平台的。

Answer 1

NTFS 文件系统有连接点，我想你可以使用它们，你可以使用 python win32 API 模块，例如

import win32file

win32file.CreateSymbolicLink(fileSrc, fileTarget, 1)

如果你不想依赖 win32API 模块，你可以随时使用 ctypes 并直接调用 CreateSymbolicLink win32 API 例如

import ctypes

kdll = ctypes.windll.LoadLibrary("kernel32.dll")

kdll.CreateSymbolicLinkA("d:\\test.txt", "d:\\test_link.txt", 0)

MSDN ( http://msdn.microsoft.com/en-us/library/aa363866(VS.85).aspx) 表示最低支持的客户端是 Windows Vista

此外：这也适用于目录（用第三个参数表示）。有了 unicode 支持，它看起来像这样：

kdll.CreateSymbolicLinkW(UR"D:\testdirLink", UR"D:\testdir", 1)

另请参阅
在 Python 中创建 NTFS 连接点

Answer 2

os.symlink 适用于使用 Windows 8.1 和 NTFS 文件系统的 Python 3.3。

Answer 3

在子进程中使用 mklink 命令创建链接。

from subprocess import call
call(['mklink', 'LINK', 'TARGET'], shell=True)

Answer 4

python ntfslink扩展

或者如果你想使用pywin32，你可以使用前面所说的方法，阅读时使用：

from win32file import *
from winioctlcon import FSCTL_GET_REPARSE_POINT

__all__ = ['islink', 'readlink']

# Win32file doesn't seem to have this attribute.
FILE_ATTRIBUTE_REPARSE_POINT = 1024
# To make things easier.
REPARSE_FOLDER = (FILE_ATTRIBUTE_DIRECTORY | FILE_ATTRIBUTE_REPARSE_POINT)

# For the parse_reparse_buffer function
SYMBOLIC_LINK = 'symbolic'
MOUNTPOINT = 'mountpoint'
GENERIC = 'generic'

def islink(fpath):
    """ Windows islink implementation. """
    if GetFileAttributes(fpath) & REPARSE_FOLDER == REPARSE_FOLDER:
        return True
    return False


def parse_reparse_buffer(original, reparse_type=SYMBOLIC_LINK):
    """ Implementing the below in Python:

    typedef struct _REPARSE_DATA_BUFFER {
        ULONG  ReparseTag;
        USHORT ReparseDataLength;
        USHORT Reserved;
        union {
            struct {
                USHORT SubstituteNameOffset;
                USHORT SubstituteNameLength;
                USHORT PrintNameOffset;
                USHORT PrintNameLength;
                ULONG Flags;
                WCHAR PathBuffer[1];
            } SymbolicLinkReparseBuffer;
            struct {
                USHORT SubstituteNameOffset;
                USHORT SubstituteNameLength;
                USHORT PrintNameOffset;
                USHORT PrintNameLength;
                WCHAR PathBuffer[1];
            } MountPointReparseBuffer;
            struct {
                UCHAR  DataBuffer[1];
            } GenericReparseBuffer;
        } DUMMYUNIONNAME;
    } REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER;

    """
    # Size of our data types
    SZULONG = 4 # sizeof(ULONG)
    SZUSHORT = 2 # sizeof(USHORT)

    # Our structure.
    # Probably a better way to iterate a dictionary in a particular order,
    # but I was in a hurry, unfortunately, so I used pkeys.
    buffer = {
        'tag' : SZULONG,
        'data_length' : SZUSHORT,
        'reserved' : SZUSHORT,
        SYMBOLIC_LINK : {
            'substitute_name_offset' : SZUSHORT,
            'substitute_name_length' : SZUSHORT,
            'print_name_offset' : SZUSHORT,
            'print_name_length' : SZUSHORT,
            'flags' : SZULONG,
            'buffer' : u'',
            'pkeys' : [
                'substitute_name_offset',
                'substitute_name_length',
                'print_name_offset',
                'print_name_length',
                'flags',
            ]
        },
        MOUNTPOINT : {
            'substitute_name_offset' : SZUSHORT,
            'substitute_name_length' : SZUSHORT,
            'print_name_offset' : SZUSHORT,
            'print_name_length' : SZUSHORT,
            'buffer' : u'',
            'pkeys' : [
                'substitute_name_offset',
                'substitute_name_length',
                'print_name_offset',
                'print_name_length',
            ]
        },
        GENERIC : {
            'pkeys' : [],
            'buffer': ''
        }
    }

    # Header stuff
    buffer['tag'] = original[:SZULONG]
    buffer['data_length'] = original[SZULONG:SZUSHORT]
    buffer['reserved'] = original[SZULONG+SZUSHORT:SZUSHORT]
    original = original[8:]

    # Parsing
    k = reparse_type
    for c in buffer[k]['pkeys']:
        if type(buffer[k][c]) == int:
            sz = buffer[k][c]
            bytes = original[:sz]
            buffer[k][c] = 0
            for b in bytes:
                n = ord(b)
                if n:
                    buffer[k][c] += n
            original = original[sz:]

    # Using the offset and length's grabbed, we'll set the buffer.
    buffer[k]['buffer'] = original
    return buffer

def readlink(fpath):
    """ Windows readlink implementation. """
    # This wouldn't return true if the file didn't exist, as far as I know.
    if not islink(fpath):
        return None

    # Open the file correctly depending on the string type.
    handle = CreateFileW(fpath, GENERIC_READ, 0, None, OPEN_EXISTING, FILE_FLAG_OPEN_REPARSE_POINT, 0) \
                if type(fpath) == unicode else \
            CreateFile(fpath, GENERIC_READ, 0, None, OPEN_EXISTING, FILE_FLAG_OPEN_REPARSE_POINT, 0)

    # MAXIMUM_REPARSE_DATA_BUFFER_SIZE = 16384 = (16*1024)
    buffer = DeviceIoControl(handle, FSCTL_GET_REPARSE_POINT, None, 16*1024)
    # Above will return an ugly string (byte array), so we'll need to parse it.

    # But first, we'll close the handle to our file so we're not locking it anymore.
    CloseHandle(handle)

    # Minimum possible length (assuming that the length of the target is bigger than 0)
    if len(buffer) < 9:
        return None
    # Parse and return our result.
    result = parse_reparse_buffer(buffer)
    offset = result[SYMBOLIC_LINK]['substitute_name_offset']
    ending = offset + result[SYMBOLIC_LINK]['substitute_name_length']
    rpath = result[SYMBOLIC_LINK]['buffer'][offset:ending].replace('\x00','')
    if len(rpath) > 4 and rpath[0:4] == '\\??\\':
        rpath = rpath[4:]
    return rpath

def realpath(fpath):
    from os import path
    while islink(fpath):
        rpath = readlink(fpath)
        if not path.isabs(rpath):
            rpath = path.abspath(path.join(path.dirname(fpath), rpath))
        fpath = rpath
    return fpath


def example():
    from os import system, unlink
    system('cmd.exe /c echo Hello World > test.txt')
    system('mklink test-link.txt test.txt')
    print 'IsLink: %s' % islink('test-link.txt')
    print 'ReadLink: %s' % readlink('test-link.txt')
    print 'RealPath: %s' % realpath('test-link.txt')
    unlink('test-link.txt')
    unlink('test.txt')

if __name__=='__main__':
    example()

Adjust CreateFile 中的属性可以满足您的需要，但对于正常情况，它应该可以工作。请随意改进它。

如果您使用 MOUNTPOINT 而不是 SYMBOLIC_LINK，它也应该适用于文件夹连接。

您可以检查一下是否

sys.getwindowsversion()[0] >= 6

将其放入要发布的内容中，因为这种形式的符号链接仅在 Vista+ 上受支持。

Answer 5

问题是，正如此处所解释的，Windows自己对符号链接功能的支持不同的 Windows 版本有所不同，因此，例如，在 Vista 中（需要做很多工作），您可以获得比 XP 或 2000 更多的功能（据我所知，在其他 win32 版本上没有）。或者您也可以使用快捷方式，当然快捷方式有其自己的限制，并且并不“真正”等同于 Unix 符号链接。所以，你必须准确地指定你需要什么功能，你愿意在跨 win32 操作的祭坛上牺牲多少功能，等等——然后，我们可以制定出如何实现你所选择的妥协方案ctypes 或 win32all 调用...从某种意义上说，这是最少的。

Answer 6

我将以下内容放入 Lib/site-packages/sitecustomize.py

import os

__CSL = None
def symlink(source, link_name):
    '''symlink(source, link_name)
       Creates a symbolic link pointing to source named link_name'''
    global __CSL
    if __CSL is None:
        import ctypes
        csl = ctypes.windll.kernel32.CreateSymbolicLinkW
        csl.argtypes = (ctypes.c_wchar_p, ctypes.c_wchar_p, ctypes.c_uint32)
        csl.restype = ctypes.c_ubyte
        __CSL = csl
    flags = 0
    if source is not None and os.path.isdir(source):
        flags = 1
    if __CSL(link_name, source, flags) == 0:
        raise ctypes.WinError()

os.symlink = symlink

Answer 7

Juntalis 的代码不处理 Unicode，因此我将其修改为使用 ctypes，并使用 struct 对其进行了简化。我还查阅了 中的代码在 python ctypes 模块中使用结构体作为函数参数

import os, ctypes, struct
from ctypes import windll, wintypes

FSCTL_GET_REPARSE_POINT = 0x900a8

FILE_ATTRIBUTE_READONLY      = 0x0001
FILE_ATTRIBUTE_HIDDEN        = 0x0002
FILE_ATTRIBUTE_DIRECTORY     = 0x0010
FILE_ATTRIBUTE_NORMAL        = 0x0080
FILE_ATTRIBUTE_REPARSE_POINT = 0x0400


GENERIC_READ  = 0x80000000
GENERIC_WRITE = 0x40000000
OPEN_EXISTING = 3
FILE_READ_ATTRIBUTES = 0x80
FILE_FLAG_OPEN_REPARSE_POINT = 0x00200000
INVALID_HANDLE_VALUE = wintypes.HANDLE(-1).value

INVALID_FILE_ATTRIBUTES = 0xFFFFFFFF

FILE_FLAG_OPEN_REPARSE_POINT = 2097152
FILE_FLAG_BACKUP_SEMANTICS = 33554432
# FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTI
FILE_FLAG_REPARSE_BACKUP = 35651584


GetFileAttributes = windll.kernel32.GetFileAttributesW
_CreateFileW = windll.kernel32.CreateFileW
_DevIoCtl = windll.kernel32.DeviceIoControl
_DevIoCtl.argtypes = [
    wintypes.HANDLE, #HANDLE hDevice
    wintypes.DWORD, #DWORD dwIoControlCode
    wintypes.LPVOID, #LPVOID lpInBuffer
    wintypes.DWORD, #DWORD nInBufferSize
    wintypes.LPVOID, #LPVOID lpOutBuffer
    wintypes.DWORD, #DWORD nOutBufferSize
    ctypes.POINTER(wintypes.DWORD), #LPDWORD lpBytesReturned
    wintypes.LPVOID] #LPOVERLAPPED lpOverlapped
_DevIoCtl.restype = wintypes.BOOL


def islink(path):
    assert os.path.isdir(path), path
    if GetFileAttributes(path) & FILE_ATTRIBUTE_REPARSE_POINT:
        return True
    else:
        return False


def DeviceIoControl(hDevice, ioControlCode, input, output):
    # DeviceIoControl Function
    # http://msdn.microsoft.com/en-us/library/aa363216(v=vs.85).aspx
    if input:
        input_size = len(input)
    else:
        input_size = 0
    if isinstance(output, int):
        output = ctypes.create_string_buffer(output)
    output_size = len(output)
    assert isinstance(output, ctypes.Array)
    bytesReturned = wintypes.DWORD()
    status = _DevIoCtl(hDevice, ioControlCode, input,
                       input_size, output, output_size, bytesReturned, None)
    print "status(%d)" % status
    if status != 0:
        return output[:bytesReturned.value]
    else:
        return None


def CreateFile(path, access, sharemode, creation, flags):
    return _CreateFileW(path, access, sharemode, None, creation, flags, None)


SymbolicLinkReparseFormat = "LHHHHHHL"
SymbolicLinkReparseSize = struct.calcsize(SymbolicLinkReparseFormat);

def readlink(path):
    """ Windows readlink implementation. """
    # This wouldn't return true if the file didn't exist, as far as I know.
    assert islink(path)
    assert type(path) == unicode

    # Open the file correctly depending on the string type.
    hfile = CreateFile(path, GENERIC_READ, 0, OPEN_EXISTING,
                       FILE_FLAG_REPARSE_BACKUP)
    # MAXIMUM_REPARSE_DATA_BUFFER_SIZE = 16384 = (16*1024)
    buffer = DeviceIoControl(hfile, FSCTL_GET_REPARSE_POINT, None, 16384)
    CloseHandle(hfile)

    # Minimum possible length (assuming length of the target is bigger than 0)
    if not buffer or len(buffer) < 9:
        return None

    # Parse and return our result.
    # typedef struct _REPARSE_DATA_BUFFER {
    #   ULONG  ReparseTag;
    #   USHORT ReparseDataLength;
    #   USHORT Reserved;
    #   union {
    #       struct {
    #           USHORT SubstituteNameOffset;
    #           USHORT SubstituteNameLength;
    #           USHORT PrintNameOffset;
    #           USHORT PrintNameLength;
    #           ULONG Flags;
    #           WCHAR PathBuffer[1];
    #       } SymbolicLinkReparseBuffer;
    #       struct {
    #           USHORT SubstituteNameOffset;
    #           USHORT SubstituteNameLength;
    #           USHORT PrintNameOffset;
    #           USHORT PrintNameLength;
    #           WCHAR PathBuffer[1];
    #       } MountPointReparseBuffer;
    #       struct {
    #           UCHAR  DataBuffer[1];
    #       } GenericReparseBuffer;
    #   } DUMMYUNIONNAME;
    # } REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER;

    # Only handle SymbolicLinkReparseBuffer
    (tag, dataLength, reserver, SubstituteNameOffset, SubstituteNameLength,
     PrintNameOffset, PrintNameLength,
     Flags) = struct.unpack(SymbolicLinkReparseFormat,
                            buffer[:SymbolicLinkReparseSize])
    print tag, dataLength, reserver, SubstituteNameOffset, SubstituteNameLength
    start = SubstituteNameOffset + SymbolicLinkReparseSize
    actualPath = buffer[start : start + SubstituteNameLength].decode("utf-16")
    # This utf-16 string is null terminated
    index = actualPath.find(u"\0")
    assert index > 0
    if index > 0:
        actualPath = actualPath[:index]
    if actualPath.startswith(u"?\\"):
        return actualPath[2:]
    else:
        return actualPath

Answer 8

正如另一个答案中提到的，使用 subprocess.call 可能是 Windows 的最佳选择。然而直接调用“mklink”可能会导致：

[WinError 2]系统找不到指定的文件

在 Windows Server 2016 上，我能够对文件执行以下操作：

import subprocess
subprocess.call(['cmd', '/c', 'mklink', '<path_for_symlink>', '<path_for_file>'])

按照 mklink 文档更改上面的开关。

Answer 9

尝试在 Windows 中创建符号链接我总是收到错误

A required privilege is not held by the client

但是使用此代码创建快捷方式时我成功了

import win32com.client
import pythoncom
import os

def create_shortcut(original_filepath, shortcut_filepath):
    shell = win32com.client.Dispatch("WScript.Shell")
    shortcut = shell.CreateShortCut(shortcut_filepath)
    shortcut.Targetpath = original_filepath
    shortcut.WindowStyle = 7
    shortcut.save()

create_shortcut(r'C:\Users\xxx\Desktop\test.jpg', 
                r'C:\Users\xxx\Desktop\test.lnk')

注意：确保快捷方式以“.lnk”结尾

Answer 10

这是包含 kernel32.dll 所有方法的链接

http://www.geoffchappell .com/studies/windows/win32/kernel32/api/

我在 Windows xp sp3 上使用了 CreateHardLinkA，它有效！

导入ctypes
如果 os.path.exists(link_file):
os.remove（链接文件）

dll = ctypes.windll.LoadLibrary("kernel32.dll")
dll.CreateHardLinkA(link_file, _log_filename, 0)

Answer 11

python3 支持 windows vista+(windows 10...) 上的符号链接，只需在提升的 cmd 中运行