Why are the ShellExecuteEx() parameters not working?

Question

Let say I want the program "C:\MyProgram.exe" to run with parameters that are two variables. The problem that occurs is that MyProgram only receives 2 parameters, while I clearly pass 3 parameters.

My code:

SHELLEXECUTEINFO    ShExecInfo = { 0 };
CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
ShExecInfo.cbSize = sizeof(SHELLEXECUTEINFO);
ShExecInfo.fMask = SEE_MASK_NOCLOSEPROCESS;
ShExecInfo.hwnd = NULL;
ShExecInfo.lpVerb = NULL;
ShExecInfo.lpDirectory = NULL;
ShExecInfo.nShow = SW_SHOW;
ShExecInfo.hInstApp = NULL;

ShExecInfo.lpFile = T("\"C:\\MyProgram.exe\"");
ShExecInfo.lpParameters = _T("\"\"") _T(" ") + dir + file[i] + _T(" ") + dir + outputfile + _T(".TIFF");
ShellExecuteEx(&ShExecInfo);
WaitForSingleObject(ShExecInfo.hProcess, 1500);
if(GetExitCodeProcess(ShExecInfo.hProcess, &exitCode)){
    MessageBox(_T("Conversion ") + file[i] + _T(" unsuccesful."), _T("TEST!"), MB_OK);
    succes = 0;
}

Because there isn't much info on the internet on variable parameters with ShellExecuteEx, I could not find a proper explanation for this.

Does any of you maybe know how to solve this issue? Thanks in advance!

score 2 · Accepted Answer · answered Mar 17 '15 at 09:53

2

Simply because your construct yields into a temporary object and the pointer to it (a CString I guess) is stored but the temporary object is already destroyed when you launch the program.

auto str = _T("\"\"") _T(" ") + dir + file[i] + _T(" ") + dir + outputfile + _T(".TIFF");
ShExecInfo.lpParameters = str;
ShellExecuteEx(&ShExecInfo);

answered Mar 17 '15 at 09:53

xMRi

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Thanks, this worked for me. What does the 'auto' keyword do exactly? Does it determine the datatype for me? – moffeltje Mar 17 '15 at 11:08
1

Yes. http://www.codeproject.com/Articles/570638/Ten-Cplusplus-Features-Every-Cplusplus-Developer – xMRi Mar 17 '15 at 11:18

score 0 · Answer 2 · answered Mar 17 '15 at 09:52

Did you check those two parameters that MyProgram receives, what values do they have?

The problem is most likely this piece of code:

ShExecInfo.lpParameters = _T("\"\"") _T(" ") + dir + file[i] + _T(" ") + dir + outputfile + _T(".TIFF");

You didn't say what types dir or file[i] have, but in general adding C style strings like this (TCHAR[] or TCHAR* are still C style strings) doesn't concatenate them, if that's what you expect to happen in this case.

Check what ShExecInfo.lpParameterscontains after that assignment, by displaying it or preferably with the debugger.

Why are the ShellExecuteEx() parameters not working?

2 Answers2