IShellLink GetPath and Dev-C++...

[cpeschke]

The best match to a search for finding a shortcut's target is http://cboard.cprogramming.com/showthread.php?t=61943.

But using Dev-C++ (4.9.9.2), I get several errors when using GetPath, here is the function...

char* getLinkTarget(char *sLink) {
      WIN32_FIND_DATA wfs;

      GetPath(sLink, MAX_PATH, &wfs, SLGP_RAWPATH);
      MessageBox(hWnd, wfs.cFileName, "GetPath", 0);
      return "";
}

Dev-C++ gives me the following errors...

[Warning] passing arg 1 of `GetPath' from incompatible pointer type
[Warning] passing arg 2 of `GetPath' makes pointer from integer without a cast
[Warning] passing arg 3 of `GetPath' from incompatible pointer type

I program through trial and error (because my only learning path for C is the internet and C for Dummies). I've tried several types of typecasting with no real change. I also can't find any examples for c (other than that post which I copied and pasted to try and get to work, which it didn't.

Any and all help is appreciated.

[anonytmouse]

Are you trying to call IShellLink::GetPath? If so, it needs to be called on a valid IShellLink object. The code in the linked thread is for C++ and will not compile in C. When faced with C++ code and you are using C, you have two choices.

The first is to leave the code as C++ and include it in your project as a seperate .cpp file. You will have to prepend the C++ function definitions with extern "C" so that they can be called from C code:

extern "C" BOOL GetShortcutTarget(LPCTSTR szShortcutFile, LPTSTR szTarget, SIZE_T cchTarget)
{
   ...

Then you will have to create a prototype at the top of your C file:

BOOL GetShortcutTarget(LPCTSTR szShortcutFile, LPTSTR szTarget, SIZE_T cchTarget);

With this done, you should be able to call the C++ functions from your .c files.

The other option, which usually involves more work, is to convert the code from C++ to C. Here is the GetShortcutTarget function converted to C:

#include <windows.h>
#include <objidl.h>   /* For IPersistFile */
#include <shlobj.h>   /* For IShellLink */

#if defined(_MSC_VER)
#pragma comment(lib, "ole32.lib")
#pragma comment(lib, "uuid.lib")
#endif


/*
 * GetShortcutTarget
 * Retrieves the path that a shortcut file points to.
 *
 * Paramaters:
 *    szShortcutFile    The path to the shortcut file.
 *    szTarget          Pointer to a buffer that will receive the target path.
 *                      The buffer length should be at least MAX_PATH characters.
 *    cchTarget         The size of the szTarget buffer, in characters.
 *
 * Return:
 *    A non-zero value is returned on success. If the function fails zero
 *    will be returned. GetLastError can NOT be called to get an additional error code.
 *
 * Runtime requirements:
 *    CoInitialize or CoInitializeEx must have been called before using this function.
 *
 * Compile requirements:
 *    C. Include <windows.h>, <objidl.h> & <shlobj.h>. Link "uuid.lib".
 */
BOOL GetShortcutTarget(LPCTSTR szShortcutFile, LPTSTR szTarget, SIZE_T cchTarget)
{
    IShellLink*    psl     = NULL;
    IPersistFile*  ppf     = NULL;
    BOOL           bResult = FALSE;

#   if !defined(UNICODE)
        WCHAR wsz[MAX_PATH];
        if (0 == MultiByteToWideChar(CP_ACP, 0, szShortcutFile, -1, wsz, MAX_PATH) )
            goto cleanup;
#   else
        LPCWSTR wsz = szShortcutFile;
#   endif

    if (FAILED( CoCreateInstance(&CLSID_ShellLink, NULL, CLSCTX_INPROC_SERVER, &IID_IShellLink, (void **) &psl) ))
        goto cleanup;

    if (FAILED( psl->lpVtbl->QueryInterface(psl, &IID_IPersistFile, (void **) &ppf) ))
        goto cleanup;

    if (FAILED( ppf->lpVtbl->Load(ppf, wsz, STGM_READ) ))
        goto cleanup;

    if (NOERROR != psl->lpVtbl->GetPath(psl, szTarget, cchTarget, NULL, 0) )
        goto cleanup;

    bResult = TRUE;

cleanup:
    if (ppf) ppf->lpVtbl->Release(ppf);
    if (psl) psl->lpVtbl->Release(psl);
    if (!bResult && cchTarget != 0) szTarget[0] = TEXT('\0');
    return bResult;
}


#if 1 /* Test code. */
#include <stdio.h>
#include <tchar.h>

int main(void)
{
    TCHAR szTarget[MAX_PATH];

    CoInitialize(NULL);

    GetShortcutTarget(
     TEXT("C:\\Documents and Settings\\All Users\\Start Menu\\")
     TEXT("Programs\\Accessories\\Calculator.lnk"),
         szTarget, MAX_PATH);

    _tprintf(TEXT("The shortcut target is '%s'.\n"), szTarget);

    CoUninitialize();
    getchar();
    return 0;
}
#endif

To compile this with Dev-C++, add -luuid -lole32 to the Linker box under Project->Project Options->Parameters tab.

[cpeschke]

I used the function and it works great! I very much appreciate the assistance. Thanks!

I tried to give you some more reputation but since you helped me with my last problem I can't give it anymore, hopefully some verbal praise will suffice, great work!