Check if process is running - Windows - c++

Question

i'm using QT to check if process is running and i used the same code in msdn site.
It worked fine on Visual Studio but i'm having a problem making it work on QT.
Here's the code :
bool matchProcessName( DWORD processID, std::string processName)
{
TCHAR szProcessName[MAX_PATH] = TEXT(L"notepad.exe");
// Get a handle to the process.
HANDLE hProcess = OpenProcess( PROCESS_QUERY_INFORMATION |
PROCESS_VM_READ,
FALSE, processID );
// Get the process name.
if (NULL != hProcess )
{
HMODULE hMod;
DWORD cbNeeded;
if ( EnumProcessModules( hProcess, &hMod, sizeof(hMod),
&cbNeeded) )
{
GetModuleBaseName( hProcess, hMod, szProcessName,
sizeof(szProcessName)/sizeof(TCHAR) );
}
}
// Compare process name with your string
bool matchFound = !_tcscmp(szProcessName, processName.c_str() );
// Release the handle to the process.
CloseHandle( hProcess );
return matchFound;
}
The Error i'm getting is this :
error: cannot convert 'TCHAR*' to 'const char*' for argument '1' to 'int strcmp(const char*, const char*)'
How can i make this work on QT ?
Thanks alot.
Update
I also tried this code :
DWORD FindProcessId(char* processName)
{
char* p = strrchr(processName, '\\');
if(p)
processName = p+1;
PROCESSENTRY32 processInfo;
processInfo.dwSize = sizeof(processInfo);
HANDLE processesSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);
if ( processesSnapshot == INVALID_HANDLE_VALUE )
return 0;
Process32First(processesSnapshot, &processInfo);
if ( !strcmp(processName, processInfo.szExeFile) )
{
CloseHandle(processesSnapshot);
return processInfo.th32ProcessID;
}
while ( Process32Next(processesSnapshot, &processInfo) )
{
if ( !strcmp(processName, processInfo.szExeFile) )
{
CloseHandle(processesSnapshot);
return processInfo.th32ProcessID;
}
}
CloseHandle(processesSnapshot);
return 0;
}
I'm also getting an error :cannot convert 'WCHAR*' to 'const char*' for argument '2' to 'int strcmp(const char*, const char*)'
I prefer if i can make 2nd method work !
Thanks again

Answer 1

It has nothing to do with Qt.
In the updated code, PROCESSENTRY32.szExeFile is a TCHAR[],
i.e. it is a WCHAR[] if the macro _UNCODE is defined else is a char[].
So you have to transfer your char *processName to TCHAR[] and use _tcscmp(...) to compare TCHAR[].
Modified code:
#include <Windows.h>
#include <TlHelp32.h>
#include <tchar.h>
#include <Psapi.h>
#include <cstring>
#include <string>
#define MIN(x, y) ((x) > (y)) ? (y) : (x)
void cstringToTCHAR(TCHAR *dst, const char *src, size_t l) {
#if defined(_UNICODE) || defined(UNICODE
mbstowcs(dst, src, l);
#else
memcpy(dst, src, l);
#endif
}
bool matchProcessName( DWORD processID, std::string processName)
{
TCHAR szProcessName[MAX_PATH] = _T("notepad.exe");
// Get a handle to the process.
HANDLE hProcess = OpenProcess( PROCESS_QUERY_INFORMATION |
PROCESS_VM_READ,
FALSE, processID );
// Get the process name.
if (NULL != hProcess )
{
HMODULE hMod;
DWORD cbNeeded;
if ( EnumProcessModules( hProcess, &hMod, sizeof(hMod),
&cbNeeded) )
{
GetModuleBaseName( hProcess, hMod, szProcessName,
sizeof(szProcessName)/sizeof(TCHAR) );
}
}
// Compare process name with your string
TCHAR systemEncodeProcessName[30];
size_t processNameLen = MIN((processName.size() + 1), 30);
cstringToTCHAR(systemEncodeProcessName, processName.c_str(), processNameLen);
bool matchFound = !_tcscmp(szProcessName, systemEncodeProcessName);
// Release the handle to the process.
CloseHandle( hProcess );
return matchFound;
}
DWORD FindProcessId(char* processName) {
char* p = strrchr(processName, '\\');
if(p) {
processName = p+1;
}
PROCESSENTRY32 processInfo;
processInfo.dwSize = sizeof(processInfo);
HANDLE processesSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);
if (processesSnapshot == INVALID_HANDLE_VALUE) {
return 0;
}
//Transfer char array to TCHAR array.
TCHAR systemEncodeProcessName[30];//Maybe need more or dynamic allocation.
size_t processNameLen = MIN((strlen(processName) + 1), 30);
cstringToTCHAR(systemEncodeProcessName, processName, processNameLen);
Process32First(processesSnapshot, &processInfo);
if (!_tcscmp(systemEncodeProcessName, processInfo.szExeFile)) {
CloseHandle(processesSnapshot);
return processInfo.th32ProcessID;
}
while ( Process32Next(processesSnapshot, &processInfo) ) {
if ( !_tcscmp(systemEncodeProcessName, processInfo.szExeFile) ) {
CloseHandle(processesSnapshot);
return processInfo.th32ProcessID;
}
}
CloseHandle(processesSnapshot);
return 0;
}
Update
In Qt creator(3.3.0), the _UNICODE macro looks like missing in Windows platform, just add
DEFINES += _UNICODE
in your .pro file and then run qmake && build.