如何从delphi 7 aplpication运行mklink系统命令（cmd.exe）

Question

In my application at runtime I want to run the cmd line Mklink /d (link location) (actual file/folder location).

So far I have:

symLink := PChar('/d C:\Data\'+fileName+' N:\"Database Archives"\'+fileName);

ShellExecute(0, nil, 'Mklink', symLink, nil, SW_SHOWNORMAL);

but I have also tried:

symLink := PChar('Mklink /d C:\Data\'+fileName+' N:\"Database Archives"\'+fileName);

ShellExecute(0, nil, 'cmd.exe', symLink, nil, SW_SHOWNORMAL);

Am I along the right lines? Is there any documentation to explain each parameter required by ShellExecute ?

Answer 1

Simply put, don't do this. Use the API. It's called CreateSymbolicLink . Pass the SYMBOLIC_LINK_FLAG_DIRECTORY flag.

This is much more robust and allows you to report errors properly, cope with systems that don't have cmd.exe and so on.

Do note that creating symbolic links requires the process to be elevated. I trust you already know that. Do also check for errors as described the linked documentation.

More broadly you'll need to reconsider the specific paths in your question. You cannot make cross volume symbolic links.

As regards documentation, these are Windows functions. Just type the name into a search engine and you will find the MSDN docs.

---

In an older Delphi you'll need to define the function because the supplied header translations don't have it.

const
  SYMBOLIC_LINK_FLAG_DIRECTORY = $00000001;

function CreateSymbolicLinkA(
  lpSymlinkFileName: PAnsiChar;
  lpTargetFileName: PAnsiChar;
  dwFlags: DWORD
): Boolean; stdcall; external 'kernel32';

function CreateSymbolicLinkW(
  lpSymlinkFileName: PWideChar;
  lpTargetFileName: PWideChar;
  dwFlags: DWORD
): Boolean; stdcall; external 'kernel32';