Page 1 of 1
Creating a hard link
Posted: Sun Sep 09, 2018 4:02 pm
by Bitblazer
The hard link requirements by microsoft for windows are : NTFS file system V5 or above, administrator rights to create them, with win32 API :
CreateHardLinkW or via commandline "{systemfolder}\cmd.exe /q /s mklink /h" (its a standard cmd.exe internal command with recent windows versions). I tried both methods and try to get a clean simple win32 api method running, but no matter which kind of string passing or pototype for import i use, i always get the result of "failed" with a lasterror() of 2 (see
error codes). I tried pointers and direct argument passing as p-utf8, p-unicode and string on PB 5.62 x86. The NTFS versions are the latest official, so it should be above Ver. 5. My OS is Windows7 x64, i wonder if i have to use the 64bit PB 5.62 version
Any hint why it does'nt work?
The snippet was comiled in a project with admin rights and i get the UAC confirmation request so that should be fine.
Code: Select all
Import "Kernel32.lib"
CreateHardLinkW(lpLinkFileName.p-unicode, lpExistingFileName.p-unicode, lpSecurityAttributes.i = 0)
GetLastError.i()
EndImport
EnableExplicit
Define LinkResult.i, ErrorCode.i = 0
Debug "link test"
LinkResult = CreateHardLinkW("e:\linktest.exe", "e:\streamwriter.exe")
If (LinkResult = 0)
Debug "Ein fehler ist aufgetreten"
ErrorCode = GetLastError()
EndIf
Debug "Ergebnis war " + Str(LinkResult) + " ErrorCode = " + Str(ErrorCode)
ignore the german text, it should be irrelevant to the problem
Re: Creating a hard link
Posted: Sun Sep 09, 2018 5:25 pm
by RSBasic
My code works:
Code: Select all
EnableExplicit
Define lpFileName$
Define lpExistingFileName$
If OpenLibrary(0, "Kernel32.dll")
Prototype CreateHardLink(lpFileName, lpExistingFileName, lpSecurityAttributes)
Define CreateHardLink.CreateHardLink = GetFunction(0, "CreateHardLinkW")
CloseLibrary(0)
EndIf
lpFileName$ = "D:\Hardlink.png"
lpExistingFileName$ = "D:\Originalfile.png"
If CreateHardLink(@lpFileName$, @lpExistingFileName$, 0)
MessageRequester("", "Hard link was created.", 0)
Else
MessageRequester("", "Hard link could not be created.", 0)
EndIf
Tested with x86 (Unicode) and x64 (Unicode).
Re: Creating a hard link
Posted: Sun Sep 09, 2018 6:04 pm
by fryquez
Works fine here, even without admin rights. What error code do you get?
Re: Creating a hard link
Posted: Sun Sep 09, 2018 6:15 pm
by skywalk
Both codes work. v562 x64 on Windows 10 Pro.
Re: Creating a hard link
Posted: Mon Sep 10, 2018 9:05 am
by Bitblazer
Thanks for the help. I am still not sure why my attempt with the .lib didnt work, but the method with .dll works even without admin mode in win7 x64. That's a definitive plus and to make this reply useful for others, here is a cleaned up and re-useable snippet for general use. Thanks again
Code snippet to create a
hard link to a file
Code: Select all
EnableExplicit
Define LibraryID.i
Prototype CreateHardLink_Type(lpFileName, lpExistingFileName, lpSecurityAttributes)
Global CreateHardLink.CreateHardLink_Type = GetFunction(0, "CreateHardLinkW")
Procedure.i CreateLink(lpFileName$, lpExistingFileName$)
Define Result.i
Result = CreateHardLink(@lpFileName$, @lpExistingFileName$, 0)
ProcedureReturn Result
EndProcedure
LibraryID = OpenLibrary(#PB_Any, "Kernel32.dll")
If (LibraryID = 0)
MessageRequester("Fatal error!", "Could not open kernel32.dll" + Chr(10) + "this should not be possible.", #PB_MessageRequester_Error | #PB_MessageRequester_Ok)
End 999
EndIf
CreateHardLink = GetFunction(LibraryID, "CreateHardLinkW")
CloseLibrary(LibraryID)
LibraryID = 0
CreateLink("e:\zz_linktest.jpg", "e:\testpicture.jpg")
MessageRequester("Success!", "Link 'zz_linktest.jpg' created", #PB_MessageRequester_Ok | #PB_MessageRequester_Info)