Thread: _popen problems

Hey everyone

I have the following code that I want to use on my web server to pipe output from a CGI interpreter (such as PHP).

Code:

// Assume that 
Extension = "php";
Options.CGI[Extension] = "c:\\PHP\\php.exe";
RealFile = "c:\\webroot\\sample.php";

bool CONNECTION::SendCGI()
{
	char psBuffer[128];
	FILE * hPipe;
	string CGIInterpreter = "\"";								// Put quotes around the name of the interpreter	
	CGIInterpreter += Options.CGI[Extension];					// Interpreter
	CGIInterpreter += "\" ";									// End quote
	CGIInterpreter += RealFile;									// Add the file to be interpreted

	if ((hPipe = _popen(CGIInterpreter.c_str(), "rt")) == NULL)			
	{															// Open a pipe
		send (SFD, "Content-type: text/html\n\nCouldn't open pipe :(",48, 0);
	}
	else 
	{
	while (!feof( hPipe ))										// Loop until output finishes
	{
		if( fread( psBuffer,1, 128, hPipe) )						// Get part of the output
		{	
			send (SFD, psBuffer, 128, 0);						// Send it
		}
	}
	fclose(hPipe);												// Close pipe	
	}												return true;
}

Now, for some reason when this runs I am told there is an illegal operation, and the service (it runs as an NT service) has to shut down.

No output is ever sent to the client. Am I doing something wrong with the pointers? I don't like to use FILE *'s but this was the only example I could find to use _popen().

If anyone has any other easier ways I could create a pipe (win32) or if you can see what I've done wrong with my code, I'd love to hear from you.

this line looks a little suspicious.

Code:

  string CGIInterpreter = "\"";

You can use CreatePipe() for making pipes on a win32 platform. However, popen is much easier to use.

Yeah, I add the "\"" so that the string ends up:

_popen ( "\"C:\\PHP\\php.exe\" c:\\webroot\\sample.php", "rt");

I put quotes around the name of the interpreter because there might be spaces in it (and so it wouldn't work without them).

Thanks for the CreatePipe tip, I'll go to MSDN and look it up.