get Executable directory cross platform

getExecutableDir.cpp

QString getExecutableDir() {
#if defined(Q_OS_MAC)
    unsigned int bufferSize = 512;
    std::vector<char> buffer(bufferSize + 1);

    if(_NSGetExecutablePath(&buffer[0], &bufferSize))
    {
        buffer.resize(bufferSize);
        _NSGetExecutablePath(&buffer[0], &bufferSize);
    }

    char* lastForwardSlash = strrchr(&buffer[0], '/');
    if (lastForwardSlash == NULL) return NULL;
    *lastForwardSlash = 0;

    return &buffer[0];
#elif defined(Q_OS_WINDOWS)
    HMODULE hModule = GetModuleHandleW(NULL);
    WCHAR path[MAX_PATH];
    DWORD retVal = GetModuleFileNameW(hModule, path, MAX_PATH);
    if (retVal == 0) return NULL;

    wchar_t *lastBackslash = wcsrchr(path, '\\');
    if (lastBackslash == NULL) return NULL;
    *lastBackslash = 0;

    return QString::fromWCharArray(path);
#elif defined(Q_OS_LINUX)
    char pBuf[FILENAME_MAX];
    int len = sizeof(pBuf);
    int bytes = MIN(readlink("/proc/self/exe", pBuf, len), len - 1);
    if (bytes >= 0) {
        pBuf[bytes] = '\0';
    }

    char* lastForwardSlash = strrchr(&pBuf[0], '/');
    if (lastForwardSlash == NULL) return NULL;
    *lastForwardSlash = '\0';

    return QString::fromStdString(pBuf);
#else
    #error getExecutableDir not implemented on this platform
#endif
}