work in progress PipeReader

PipeReader.h

#pragma once

#include "ofMain.h"


extern "C"
{
	#include <fcntl.h>
	#include <stdio.h>
	#include <sys/stat.h>
	#include <unistd.h>
};

#define PIPE_BUFFER_SIZE 32

class ofxPipeListenerEventData
{
public:
	ofxPipeListenerEventData(char character_)
	{
		character = character_;
	}
	char character;
};

class ofxPipeListener
{
public:
	virtual void onCharacterReceived(ofxPipeListenerEventData& e) = 0;
};

class PipeReader : public ofThread{

public:
	
	string namedPipe;
	int fd;	
	ofxPipeListener* listener;
	PipeReader()
	{
		listener = NULL;
	}

	void start(ofxPipeListener *listener_)
	{
		listener = listener_;
		namedPipe = ofToDataPath("ofpipe", true);
		ofFile file(namedPipe, ofFile::ReadWrite, false);
		if (!file.exists()) 
		{
			bool didCreate = file.create();
			if (didCreate) 
			{
				ofLogVerbose() << "file creation PASS " << namedPipe;
			}else 
			{
				ofLogError() << "file creation FAIL " << namedPipe;
			}

		}else 
		{
			ofLogVerbose() << namedPipe << " EXISTS";
		}

		
		mkfifo(namedPipe.c_str(), 0777);
		
		startThread(true, false);
	}

	void stop()
	{
		
		stopThread();
	}

	void threadedFunction()
	{
		while( isThreadRunning())
		{
			ofBuffer pipeContents = ofBufferFromFile(namedPipe, false);
			char * content = pipeContents.getBinaryBuffer();
			if (content[0] != 0) 
			{
				ofxPipeListenerEventData eventData(content[0]);
				listener->onCharacterReceived(eventData);
				pipeContents.clear();
				ofBufferToFile(namedPipe, pipeContents, false);
			}
		}
	}
};

testApp.cpp

#include "testApp.h"

string info="";
void testApp::onCharacterReceived(ofxPipeListenerEventData& e)
{
  info+=ofToString(e.character)+"\n";	
}
//--------------------------------------------------------------
void testApp::setup(){
	ofSetLogLevel(OF_LOG_VERBOSE);	
	pipeReader.start(this);
}

//--------------------------------------------------------------
void testApp::update(){
	
}

//--------------------------------------------------------------
void testApp::draw(){
	ofDrawBitmapStringHighlight(info, 100, 100, ofColor::yellow, ofColor::blue);
}

testApp.h

#pragma once

#include "ofMain.h"
#include "PipeReader.h"

class testApp : public ofBaseApp, public ofxPipeListener{
  public:
		void setup();
		void update();
		void draw();
		
		void keyPressed(int key);
		void keyReleased(int key);
		void mouseMoved(int x, int y);
		void mouseDragged(int x, int y, int button);
		void mousePressed(int x, int y, int button);
		void mouseReleased(int x, int y, int button);
		void windowResized(int w, int h);
		void dragEvent(ofDragInfo dragInfo);
		void gotMessage(ofMessage msg);
	PipeReader pipeReader;
	void onCharacterReceived(ofxPipeListenerEventData& e);
};

example usage:
echo "c" > /home/pi/openFrameworks/apps/sandbox/pipeApp/bin/data/ofpipe