ERROR_FILE_NOT_FOUND while CreateProcess - winapi

Question

Trying to run notepad by using CreateProcess:
void _tmain( int argc, TCHAR *argv[] )
{
STARTUPINFO si;
PROCESS_INFORMATION pi;
ZeroMemory( &si, sizeof(si) );
si.cb = sizeof(si);
ZeroMemory( &pi, sizeof(pi) );
// Start the child process.
if( !CreateProcess( "notepad.exe", // No module name (use command line)
NULL, // Command line
NULL, // Process handle not inheritable
NULL, // Thread handle not inheritable
FALSE, // Set handle inheritance to FALSE
0, // No creation flags
NULL, // Use parent's environment block
NULL, // Use parent's starting directory
&si, // Pointer to STARTUPINFO structure
&pi ) // Pointer to PROCESS_INFORMATION structure
)
{
printf( "CreateProcess failed (%d).\n", GetLastError() );
return;
}
// Wait until child process exits.
WaitForSingleObject( pi.hProcess, INFINITE );
// Close process and thread handles.
CloseHandle( pi.hProcess );
CloseHandle( pi.hThread );
}
Have error in output 2. This means ERROR_FILE_NOT_FOUND. Where I should start seek for a problem? Does it means it can't find notepad.exe?

Answer 1

The lpApplicationName parameter must provide the full path to the application, not only its name.
More exactly:
The string can specify the full path and file name of the module to
execute or it can specify a partial name. In the case of a partial
name, the function uses the current drive and current directory to
complete the specification. The function will not use the search path.
This parameter must include the file name extension; no default
extension is assumed.
But you're supposedly not in the current folder of notepad.exe. So if you want use the name only, set it in the second argument, lpCommandLine. And note that this string is not a constant because it is defined as an LPTSTR parameter this way:
BOOL WINAPI CreateProcess(
_In_opt_ LPCTSTR lpApplicationName,
_Inout_opt_ LPTSTR lpCommandLine, [...]
So you have 2 variants:
STARTUPINFO si = { sizeof(si) };
PROCESS_INFORMATION pi;
WCHAR CommandLine[] = L"notepad.exe";
if( CreateProcess( 0, // No module name (use command line)
CommandLine, // Command line
NULL, // Process handle not inheritable
NULL, // Thread handle not inheritable
FALSE, // Set handle inheritance to FALSE
0, // No creation flags
NULL, // Use parent's environment block
NULL, // Use parent's starting directory
&si, // Pointer to STARTUPINFO structure
&pi ) // Pointer to PROCESS_INFORMATION structure
)
{
CloseHandle(pi.hThread);
CloseHandle(pi.hProcess);
}
or
STARTUPINFO si = { sizeof(si) };
PROCESS_INFORMATION pi;
if( CreateProcess( L"c:\\windows\\notepad.exe",
0, // Command line
NULL, // Process handle not inheritable
NULL, // Thread handle not inheritable
FALSE, // Set handle inheritance to FALSE
0, // No creation flags
NULL, // Use parent's environment block
NULL, // Use parent's starting directory
&si, // Pointer to STARTUPINFO structure
&pi ) // Pointer to PROCESS_INFORMATION structure
)
{
CloseHandle(pi.hThread);
CloseHandle(pi.hProcess);
}