Question

I have this

static std::string exec(char* cmd) {
            FILE* pipe = _popen(cmd, "r");
            if (!pipe) return "ERROR -22";
            char buffer[128];
            std::string result = "";
            while(!feof(pipe)) {
                if(fgets(buffer, 128, pipe) != NULL)
                        result += buffer;
            }
            _pclose(pipe);
            return result;

}

But the problem i have is that i want to hide the program that lunches how can I do that? thx

Answer 1

As Hans Passant mentioned in the comments, you have to use CreateProcess to spawn the child process instead of _popen, since _popen does not give you any control over the window creation process.

To hide the console window, use the CREATE_NO_WINDOW process creation flag for the dwCreationFlags parameter.

In order to capture the output of the process, you need to create a pipe for its standard output stream with CreatePipe. Assign that pipe handle to the hStdOutput member of the STARTUPINFO structure you pass in, and make sure to set the STARTF_USESTDHANDLES flag in the startup info’s dwFlags so it knows that that member is valid. Then, to read data, you just use ReadFile on the pipe handle.

Hans also provided a link to a good example of creating pipes with a child process here, although that example is doing more than you need to do—it’s creating pipes for all three streams (stdin, stdout, and stderr), whereas you only need to capture stdout.