I'm trying to read the target file/directory of a shortcut (.lnk
) file from Python. Is there a headache-free way to do it? The .lnk spec [PDF] is way over my head.
I don't mind using Windows-only APIs.
My ultimate goal is to find the "(My) Videos"
folder on Windows XP and Vista. On XP, by default, it's at %HOMEPATH%\My Documents\My Videos
, and on Vista it's %HOMEPATH%\Videos
. However, the user can relocate this folder. In the case, the %HOMEPATH%\Videos
folder ceases to exists and is replaced by %HOMEPATH%\Videos.lnk
which points to the new "My Videos"
folder. And I want its absolute location.
Create a shortcut using Python (via WSH)
import sys
import win32com.client
shell = win32com.client.Dispatch("WScript.Shell")
shortcut = shell.CreateShortCut("t:\\test.lnk")
shortcut.Targetpath = "t:\\ftemp"
shortcut.save()
Read the Target of a Shortcut using Python (via WSH)
import sys
import win32com.client
shell = win32com.client.Dispatch("WScript.Shell")
shortcut = shell.CreateShortCut("t:\\test.lnk")
print(shortcut.Targetpath)
Basically call the Windows API directly. Here is a good example found after Googling:
import os, sys
import pythoncom
from win32com.shell import shell, shellcon
shortcut = pythoncom.CoCreateInstance (
shell.CLSID_ShellLink,
None,
pythoncom.CLSCTX_INPROC_SERVER,
shell.IID_IShellLink
)
desktop_path = shell.SHGetFolderPath (0, shellcon.CSIDL_DESKTOP, 0, 0)
shortcut_path = os.path.join (desktop_path, "python.lnk")
persist_file = shortcut.QueryInterface (pythoncom.IID_IPersistFile)
persist_file.Load (shortcut_path)
shortcut.SetDescription ("Updated Python %s" % sys.version)
mydocs_path = shell.SHGetFolderPath (0, shellcon.CSIDL_PERSONAL, 0, 0)
shortcut.SetWorkingDirectory (mydocs_path)
persist_file.Save (shortcut_path, 0)
This is from http://timgolden.me.uk/python/win32_how_do_i/create-a-shortcut.html.
You can search for "python ishelllink" for other examples.
Also, the API reference helps too: http://msdn.microsoft.com/en-us/library/bb774950(VS.85).aspx
Alternatively, you could try using SHGetFolderPath(). The following code might work, but I'm not on a Windows machine right now so I can't test it.
import ctypes
shell32 = ctypes.windll.shell32
# allocate MAX_PATH bytes in buffer
video_folder_path = ctypes.create_string_buffer(260)
# 0xE is CSIDL_MYVIDEO
# 0 is SHGFP_TYPE_CURRENT
# If you want a Unicode path, use SHGetFolderPathW instead
if shell32.SHGetFolderPathA(None, 0xE, None, 0, video_folder_path) >= 0:
# success, video_folder_path now contains the correct path
else:
# error
I know this is an older thread but I feel that there isn't much information on the method that uses the link specification as noted in the original question.
My shortcut target implementation could not use the win32com module and after a lot of searching, decided to come up with my own. Nothing else seemed to accomplish what I needed under my restrictions. Hopefully this will help other folks in this same situation.
It uses the binary structure Microsoft has provided for MS-SHLLINK.
import struct
path = 'myfile.txt.lnk'
target = ''
with open(path, 'rb') as stream:
content = stream.read()
# skip first 20 bytes (HeaderSize and LinkCLSID)
# read the LinkFlags structure (4 bytes)
lflags = struct.unpack('I', content[0x14:0x18])[0]
position = 0x18
# if the HasLinkTargetIDList bit is set then skip the stored IDList
# structure and header
if (lflags & 0x01) == 1:
position = struct.unpack('H', content[0x4C:0x4E])[0] + 0x4E
last_pos = position
position += 0x04
# get how long the file information is (LinkInfoSize)
length = struct.unpack('I', content[last_pos:position])[0]
# skip 12 bytes (LinkInfoHeaderSize, LinkInfoFlags, and VolumeIDOffset)
position += 0x0C
# go to the LocalBasePath position
lbpos = struct.unpack('I', content[position:position+0x04])[0]
position = last_pos + lbpos
# read the string at the given position of the determined length
size= (length + last_pos) - position - 0x02
temp = struct.unpack('c' * size, content[position:position+size])
target = ''.join([chr(ord(a)) for a in temp])
I also realize this question is old, but I found the answers to be most relevant to my situation.
Like Jared's answer, I also could not use the win32com module. So Jared's use of the binary structure from MS-SHLLINK got me part of the way there. I needed read shortcuts on both Windows and Linux, where the shortcuts are created on a samba share by Windows. Jared's implementation didn't quite work for me, I think only because I encountered some different variations on the shortcut format. But, it gave me the start I needed (thanks Jared).
So, here is a class named MSShortcut which expands on Jared's approach. However, the implementation is only Python3.4 and above, due to using some pathlib features added in Python3.4
#!/usr/bin/python3
# Link Format from MS: https://msdn.microsoft.com/en-us/library/dd871305.aspx
# Need to be able to read shortcut target from .lnk file on linux or windows.
# Original inspiration from: http://stackoverflow.com/questions/397125/reading-the-target-of-a-lnk-file-in-python
from pathlib import Path, PureWindowsPath
import struct, sys, warnings
if sys.hexversion < 0x03040000:
warnings.warn("'{}' module requires python3.4 version or above".format(__file__), ImportWarning)
# doc says class id =
# 00021401-0000-0000-C000-000000000046
# requiredCLSID = b'\x00\x02\x14\x01\x00\x00\x00\x00\xC0\x00\x00\x00\x00\x00\x00\x46'
# Actually Getting:
requiredCLSID = b'\x01\x14\x02\x00\x00\x00\x00\x00\xC0\x00\x00\x00\x00\x00\x00\x46' # puzzling
class ShortCutError(RuntimeError):
pass
class MSShortcut():
"""
interface to Microsoft Shortcut Objects. Purpose:
- I need to be able to get the target from a samba shared on a linux machine
- Also need to get access from a Windows machine.
- Need to support several forms of the shortcut, as they seem be created differently depending on the
creating machine.
- Included some 'flag' types in external interface to help test differences in shortcut types
Args:
scPath (str): path to shortcut
Limitations:
- There are some omitted object properties in the implementation.
Only implemented / tested enough to recover the shortcut target information. Recognized omissions:
- LinkTargetIDList
- VolumeId structure (if captured later, should be a separate class object to hold info)
- Only captured environment block from extra data
- I don't know how or when some of the shortcut information is used, only captured what I recognized,
so there may be bugs related to use of the information
- NO shortcut update support (though might be nice)
- Implementation requires python 3.4 or greater
- Tested only with Unicode data on a 64bit little endian machine, did not consider potential endian issues
Not Debugged:
- localBasePath - didn't check if parsed correctly or not.
- commonPathSuffix
- commonNetworkRelativeLink
"""
def __init__(self, scPath):
"""
Parse and keep shortcut properties on creation
"""
self.scPath = Path(scPath)
self._clsid = None
self._lnkFlags = None
self._lnkInfoFlags = None
self._localBasePath = None
self._commonPathSuffix = None
self._commonNetworkRelativeLink = None
self._name = None
self._relativePath = None
self._workingDir = None
self._commandLineArgs = None
self._iconLocation = None
self._envTarget = None
self._ParseLnkFile(self.scPath)
@property
def clsid(self):
return self._clsid
@property
def lnkFlags(self):
return self._lnkFlags
@property
def lnkInfoFlags(self):
return self._lnkInfoFlags
@property
def localBasePath(self):
return self._localBasePath
@property
def commonPathSuffix(self):
return self._commonPathSuffix
@property
def commonNetworkRelativeLink(self):
return self._commonNetworkRelativeLink
@property
def name(self):
return self._name
@property
def relativePath(self):
return self._relativePath
@property
def workingDir(self):
return self._workingDir
@property
def commandLineArgs(self):
return self._commandLineArgs
@property
def iconLocation(self):
return self._iconLocation
@property
def envTarget(self):
return self._envTarget
@property
def targetPath(self):
"""
Args:
woAnchor (bool): remove the anchor (\\server\path or drive:) from returned path.
Returns:
a libpath PureWindowsPath object for combined workingDir/relative path
or the envTarget
Raises:
ShortCutError when no target path found in Shortcut
"""
target = None
if self.workingDir:
target = PureWindowsPath(self.workingDir)
if self.relativePath:
target = target / PureWindowsPath(self.relativePath)
else: target = None
if not target and self.envTarget:
target = PureWindowsPath(self.envTarget)
if not target:
raise ShortCutError("Unable to retrieve target path from MS Shortcut: shortcut = {}"
.format(str(self.scPath)))
return target
@property
def targetPathWOAnchor(self):
tp = self.targetPath
return tp.relative_to(tp.anchor)
def _ParseLnkFile(self, lnkPath):
with lnkPath.open('rb') as f:
content = f.read()
# verify size (4 bytes)
hdrSize = struct.unpack('I', content[0x00:0x04])[0]
if hdrSize != 0x4C:
raise ShortCutError("MS Shortcut HeaderSize = {}, but required to be = {}: shortcut = {}"
.format(hdrSize, 0x4C, str(lnkPath)))
# verify LinkCLSID id (16 bytes)
self._clsid = bytes(struct.unpack('B'*16, content[0x04:0x14]))
if self._clsid != requiredCLSID:
raise ShortCutError("MS Shortcut ClassID = {}, but required to be = {}: shortcut = {}"
.format(self._clsid, requiredCLSID, str(lnkPath)))
# read the LinkFlags structure (4 bytes)
self._lnkFlags = struct.unpack('I', content[0x14:0x18])[0]
#logger.debug("lnkFlags=0x%0.8x" % self._lnkFlags)
position = 0x4C
# if HasLinkTargetIDList bit, then position to skip the stored IDList structure and header
if (self._lnkFlags & 0x01):
idListSize = struct.unpack('H', content[position:position+0x02])[0]
position += idListSize + 2
# if HasLinkInfo, then process the linkinfo structure
if (self._lnkFlags & 0x02):
(linkInfoSize, linkInfoHdrSize, self._linkInfoFlags,
volIdOffset, localBasePathOffset,
cmnNetRelativeLinkOffset, cmnPathSuffixOffset) = struct.unpack('IIIIIII', content[position:position+28])
# check for optional offsets
localBasePathOffsetUnicode = None
cmnPathSuffixOffsetUnicode = None
if linkInfoHdrSize >= 0x24:
(localBasePathOffsetUnicode, cmnPathSuffixOffsetUnicode) = struct.unpack('II', content[position+28:position+36])
#logger.debug("0x%0.8X" % linkInfoSize)
#logger.debug("0x%0.8X" % linkInfoHdrSize)
#logger.debug("0x%0.8X" % self._linkInfoFlags)
#logger.debug("0x%0.8X" % volIdOffset)
#logger.debug("0x%0.8X" % localBasePathOffset)
#logger.debug("0x%0.8X" % cmnNetRelativeLinkOffset)
#logger.debug("0x%0.8X" % cmnPathSuffixOffset)
#logger.debug("0x%0.8X" % localBasePathOffsetUnicode)
#logger.debug("0x%0.8X" % cmnPathSuffixOffsetUnicode)
# if info has a localBasePath
if (self._linkInfoFlags & 0x01):
bpPosition = position + localBasePathOffset
# not debugged - don't know if this works or not
self._localBasePath = UnpackZ('z', content[bpPosition:])[0].decode('ascii')
#logger.debug("localBasePath: {}".format(self._localBasePath))
if localBasePathOffsetUnicode:
bpPosition = position + localBasePathOffsetUnicode
self._localBasePath = UnpackUnicodeZ('z', content[bpPosition:])[0]
self._localBasePath = self._localBasePath.decode('utf-16')
#logger.debug("localBasePathUnicode: {}".format(self._localBasePath))
# get common Path Suffix
cmnSuffixPosition = position + cmnPathSuffixOffset
self._commonPathSuffix = UnpackZ('z', content[cmnSuffixPosition:])[0].decode('ascii')
#logger.debug("commonPathSuffix: {}".format(self._commonPathSuffix))
if cmnPathSuffixOffsetUnicode:
cmnSuffixPosition = position + cmnPathSuffixOffsetUnicode
self._commonPathSuffix = UnpackUnicodeZ('z', content[cmnSuffixPosition:])[0]
self._commonPathSuffix = self._commonPathSuffix.decode('utf-16')
#logger.debug("commonPathSuffix: {}".format(self._commonPathSuffix))
# check for CommonNetworkRelativeLink
if (self._linkInfoFlags & 0x02):
relPosition = position + cmnNetRelativeLinkOffset
self._commonNetworkRelativeLink = CommonNetworkRelativeLink(content, relPosition)
position += linkInfoSize
# If HasName
if (self._lnkFlags & 0x04):
(position, self._name) = self.readStringObj(content, position)
#logger.debug("name: {}".format(self._name))
# get relative path string
if (self._lnkFlags & 0x08):
(position, self._relativePath) = self.readStringObj(content, position)
#logger.debug("relPath='{}'".format(self._relativePath))
# get working dir string
if (self._lnkFlags & 0x10):
(position, self._workingDir) = self.readStringObj(content, position)
#logger.debug("workingDir='{}'".format(self._workingDir))
# get command line arguments
if (self._lnkFlags & 0x20):
(position, self._commandLineArgs) = self.readStringObj(content, position)
#logger.debug("commandLineArgs='{}'".format(self._commandLineArgs))
# get icon location
if (self._lnkFlags & 0x40):
(position, self._iconLocation) = self.readStringObj(content, position)
#logger.debug("iconLocation='{}'".format(self._iconLocation))
# look for environment properties
if (self._lnkFlags & 0x200):
while True:
size = struct.unpack('I', content[position:position+4])[0]
#logger.debug("blksize=%d" % size)
if size==0: break
signature = struct.unpack('I', content[position+4:position+8])[0]
#logger.debug("signature=0x%0.8x" % signature)
# EnvironmentVariableDataBlock
if signature == 0xA0000001:
if (self._lnkFlags & 0x80): # unicode
self._envTarget = UnpackUnicodeZ('z', content[position+268:])[0]
self._envTarget = self._envTarget.decode('utf-16')
else:
self._envTarget = UnpackZ('z', content[position+8:])[0].decode('ascii')
#logger.debug("envTarget='{}'".format(self._envTarget))
position += size
def readStringObj(self, scContent, position):
"""
returns:
tuple: (newPosition, string)
"""
strg = ''
size = struct.unpack('H', scContent[position:position+2])[0]
#logger.debug("workingDirSize={}".format(size))
if (self._lnkFlags & 0x80): # unicode
size *= 2
strg = struct.unpack(str(size)+'s', scContent[position+2:position+2+size])[0]
strg = strg.decode('utf-16')
else:
strg = struct.unpack(str(size)+'s', scContent[position+2:position+2+size])[0].decode('ascii')
#logger.debug("strg='{}'".format(strg))
position += size + 2 # 2 bytes to account for CountCharacters field
return (position, strg)
class CommonNetworkRelativeLink():
def __init__(self, scContent, linkContentPos):
self._networkProviderType = None
self._deviceName = None
self._netName = None
(linkSize, flags, netNameOffset,
devNameOffset, self._networkProviderType) = struct.unpack('IIIII', scContent[linkContentPos:linkContentPos+20])
#logger.debug("netnameOffset = {}".format(netNameOffset))
if netNameOffset > 0x014:
(netNameOffsetUnicode, devNameOffsetUnicode) = struct.unpack('II', scContent[linkContentPos+20:linkContentPos+28])
#logger.debug("netnameOffsetUnicode = {}".format(netNameOffsetUnicode))
self._netName = UnpackUnicodeZ('z', scContent[linkContentPos+netNameOffsetUnicode:])[0]
self._netName = self._netName.decode('utf-16')
self._deviceName = UnpackUnicodeZ('z', scContent[linkContentPos+devNameOffsetUnicode:])[0]
self._deviceName = self._deviceName.decode('utf-16')
else:
self._netName = UnpackZ('z', scContent[linkContentPos+netNameOffset:])[0].decode('ascii')
self._deviceName = UnpackZ('z', scContent[linkContentPos+devNameOffset:])[0].decode('ascii')
@property
def deviceName(self):
return self._deviceName
@property
def netName(self):
return self._netName
@property
def networkProviderType(self):
return self._networkProviderType
def UnpackZ (fmt, buf) :
"""
Unpack Null Terminated String
"""
#logger.debug(bytes(buf))
while True :
pos = fmt.find ('z')
if pos < 0 :
break
z_start = struct.calcsize (fmt[:pos])
z_len = buf[z_start:].find(b'\0')
#logger.debug(z_len)
fmt = '%s%dsx%s' % (fmt[:pos], z_len, fmt[pos+1:])
#logger.debug("fmt='{}', len={}".format(fmt, z_len))
fmtlen = struct.calcsize(fmt)
return struct.unpack (fmt, buf[0:fmtlen])
def UnpackUnicodeZ (fmt, buf) :
"""
Unpack Null Terminated String
"""
#logger.debug(bytes(buf))
while True :
pos = fmt.find ('z')
if pos < 0 :
break
z_start = struct.calcsize (fmt[:pos])
# look for null bytes by pairs
z_len = 0
for i in range(z_start,len(buf),2):
if buf[i:i+2] == b'\0\0':
z_len = i-z_start
break
fmt = '%s%dsxx%s' % (fmt[:pos], z_len, fmt[pos+1:])
# logger.debug("fmt='{}', len={}".format(fmt, z_len))
fmtlen = struct.calcsize(fmt)
return struct.unpack (fmt, buf[0:fmtlen])
I hope this helps others as well.
Thanks