diff --git a/Makefile b/Makefile
index 8c0da25..8c80416 100644
--- a/Makefile
+++ b/Makefile
@@ -9,6 +9,11 @@ sbin  := $(DESTDIR)/sbin
 man8 := $(DESTDIR)/share/man/man8/
 
 all: nethogs decpcap_test
+
+runtests: test
+	./test
+	
+	
 # nethogs_testsum
 
 CFLAGS=-g -Wall -Wextra
@@ -29,8 +34,11 @@ install: nethogs nethogs.8
 	install -d -m 755 $(man8)
 	install -m 644 nethogs.8 $(man8)
 
-nethogs: nethogs.cpp $(OBJS)
-	$(CXX) $(CFLAGS) nethogs.cpp $(OBJS) -o nethogs -lpcap -lm -lncurses -DVERSION=\"$(VERSION)\" -DSUBVERSION=\"$(SUBVERSION)\" -DMINORVERSION=\"$(MINORVERSION)\"
+test: test.cpp 
+	$(CXX) $(CFLAGS) test.cpp -o test -lpcap -lm -lncurses -DVERSION=\"$(VERSION)\" -DSUBVERSION=\"$(SUBVERSION)\" -DMINORVERSION=\"$(MINORVERSION)\"
+
+nethogs: main.cpp nethogs.cpp $(OBJS)
+	$(CXX) $(CFLAGS) main.cpp $(OBJS) -o nethogs -lpcap -lm -lncurses -DVERSION=\"$(VERSION)\" -DSUBVERSION=\"$(SUBVERSION)\" -DMINORVERSION=\"$(MINORVERSION)\"
 nethogs_testsum: nethogs_testsum.cpp $(OBJS)
 	$(CXX) $(CFLAGS) -g nethogs_testsum.cpp $(OBJS) -o nethogs_testsum -lpcap -lm -lncurses -DVERSION=\"$(VERSION)\" -DSUBVERSION=\"$(SUBVERSION)\" -DMINORVERSION=\"$(MINORVERSION)\"
 
@@ -62,3 +70,4 @@ cui.o: cui.cpp cui.h nethogs.h
 clean:
 	rm -f $(OBJS)
 	rm -f nethogs
+	rm -f test
diff --git a/README b/README
index f4a2fe1..2dc6cd0 100644
--- a/README
+++ b/README
@@ -18,8 +18,28 @@ Ideas/ToDo for new releases:
 * Make it work correctly on machines with multiple IP addresses
 * Integrate into another tool?? 
 
+== CODING STANDARDS ==
+
+Can anyone recommend a sensible set? :)
+
+For now:
+* '{' 
+** on a new line for function definitions
+** on a new line for enums
+** on the same line for conditionals/loops 
+** omitted when possible
+* use tab for indentation
+* use doxygen/javadoc-style comments.
+  * for multiline doxygen docs, add a newline after '/**'
+* case
+** classes: camelcased, start uppercase
+** enums: camelcased, start uppercase
+** functions: camelcased, start lowercase
+** local variables: camelcased, start lowercase
+
+
 == LICENSE ==
 
-Copyright 2004-2005, 2008, 2010-2011 Arnout Engelen <arnouten@bzzt.net>
+Copyright 2004-2005, 2008, 2010-2012 Arnout Engelen <arnouten@bzzt.net>
 License: nethogs may be redistributed under the terms of the GPLv2 or any 
 later version. See the COPYING file for the license text.
diff --git a/connection.cpp b/connection.cpp
index eb037c7..cfc03d2 100644
--- a/connection.cpp
+++ b/connection.cpp
@@ -25,17 +25,7 @@
 #include <malloc.h>
 #include "nethogs.h"
 #include "connection.h"
-
-class ConnList
-{
-public:
-	ConnList (Connection * m_val = NULL, ConnList * m_next = NULL)
-	{
-	    val = m_val; next = m_next;
-	}
-	Connection * val;
-	ConnList * next;
-};
+#include "process.h"
 
 ConnList * connections = NULL;
 
@@ -127,22 +117,22 @@ Connection::~Connection ()
 	ConnList * prev_conn = NULL;
 	while (curr_conn != NULL)
 	{
-		if (curr_conn->val == this)
+		if (curr_conn->getVal() == this)
 		{
 			ConnList * todelete = curr_conn;
-			curr_conn = curr_conn->next;
+			curr_conn = curr_conn->getNext();
 			if (prev_conn == NULL)
 			{
 				connections = curr_conn;
 			} else {
-				prev_conn->next = curr_conn;
+				prev_conn->setNext(curr_conn);
 			}
 			delete (todelete);
 		}
 		else
 		{
 			prev_conn = curr_conn;
-			curr_conn = curr_conn->next;
+			curr_conn = curr_conn->getNext();
 		}
 	}
 }
@@ -186,12 +176,12 @@ Connection * findConnection (Packet * packet)
 	while (current != NULL)
 	{
 		/* the reference packet is always *outgoing* */
-		if (packet->match(current->val->refpacket))
+		if (packet->match(current->getVal()->refpacket))
 		{
-			return current->val;
+			return current->getVal();
 		}
 
-		current = current->next;
+		current = current->getNext();
 	}
 
 	// Try again, now with the packet inverted:
@@ -201,13 +191,13 @@ Connection * findConnection (Packet * packet)
 	while (current != NULL)
 	{
 		/* the reference packet is always *outgoing* */
-		if (invertedPacket->match(current->val->refpacket))
+		if (invertedPacket->match(current->getVal()->refpacket))
 		{
 			delete invertedPacket;
-			return current->val;
+			return current->getVal();
 		}
 
-		current = current->next;
+		current = current->getNext();
 	}
 
 	delete invertedPacket;
diff --git a/cui.cpp b/cui.cpp
index 5d9541b..6f8595d 100644
--- a/cui.cpp
+++ b/cui.cpp
@@ -25,6 +25,7 @@
 #include <pwd.h>
 #include <sys/types.h>
 #include <stdlib.h>
+#include <errno.h>
 #include <cstdlib>
 #include <algorithm>
 
@@ -34,8 +35,7 @@
 
 
 std::string * caption;
-//extern char [] version;
-const char version[] = " version " VERSION "." SUBVERSION "." MINORVERSION;
+extern const char version[];
 extern ProcList * processes;
 extern timeval curtime;
 
@@ -79,20 +79,33 @@ private:
 	uid_t m_uid;
 };
 
-char * uid2username (uid_t uid)
+#include <sstream>
+
+std::string itoa(int i)
+{
+	std::stringstream out;
+	out << i;
+	return out.str();
+}
+
+/**
+ * @returns the username that corresponds to this uid 
+ */
+std::string uid2username (uid_t uid)
 {
 	struct passwd * pwd = NULL;
-	/* getpwuid() allocates space for this itself,
-	 * which we shouldn't free */
+	errno = NULL;
+
+	/* points to a static memory area, should not be freed */
 	pwd = getpwuid(uid);
 
 	if (pwd == NULL)
-	{
-		assert(false);
-		return strdup ("unlisted");
-	} else {
-		return strdup(pwd->pw_name);
-	}
+		if (errno == 0)
+			return itoa(uid);
+		else
+			forceExit(false, "Error calling getpwuid(3) for uid %d: %d %s", uid, errno, strerror(errno));
+	else
+		return std::string(pwd->pw_name);
 }
 
 
@@ -111,9 +124,8 @@ void Line::show (int row, unsigned int proglen)
 		mvprintw (3+row, 0, "?");
 	else
 		mvprintw (3+row, 0, "%d", m_pid);
-	char * username = uid2username(m_uid);
-	mvprintw (3+row, 6, "%s", username);
-	free (username);
+	std::string username = uid2username(m_uid);
+	mvprintw (3+row, 6, "%s", username.c_str());
 	if (strlen (m_name) > proglen) {
 		// truncate oversized names
 		char * tmp = strdup(m_name);
@@ -191,7 +203,7 @@ void init_ui ()
 	cbreak();
 	nodelay(screen, TRUE);
 	caption = new std::string ("NetHogs");
-	caption->append(version);
+	caption->append(getVersion());
 	//caption->append(", running at ");
 }
 
@@ -430,7 +442,7 @@ void do_refresh()
 			}
 			else
 			{
-				forceExit("Invalid viewmode", -1);
+				forceExit(false, "Invalid viewMode: %d", viewMode);
 			}
 			uid_t uid = curproc->getVal()->getUid();
 #ifndef NDEBUG
diff --git a/decpcap.h b/decpcap.h
index 8f7dd2c..a64255a 100644
--- a/decpcap.h
+++ b/decpcap.h
@@ -18,7 +18,8 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  */
-
+#ifndef __DECPCAP_H
+#define __DECPCAP_H
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -84,3 +85,5 @@ int dp_datalink(struct dp_handle * handle);
 int dp_setnonblock (struct dp_handle * handle, int i, char * errbuf);
 
 char * dp_geterr (struct dp_handle * handle);
+
+#endif
diff --git a/devices.h b/devices.h
index 68d4fda..6652305 100644
--- a/devices.h
+++ b/devices.h
@@ -19,6 +19,8 @@
  *
  */
 
+#ifndef __DEVICES_H
+#define __DEVICES_H
 
 #include <cstddef> // NULL
 
@@ -33,3 +35,5 @@ public:
 };
 
 device * determine_default_device();
+
+#endif
diff --git a/inode2prog.h b/inode2prog.h
index 92d8e31..120dc5f 100644
--- a/inode2prog.h
+++ b/inode2prog.h
@@ -18,7 +18,8 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  */
-
+#ifndef __INODE2PROG_h
+#define __INODE2PROG_h
 
 /* this should be called quickly after the packet
  * arrived, since the inode may disappear from the table
@@ -39,3 +40,5 @@ void prg_cache_clear();
  
 // reread the inode-to-prg_node-mapping
 void reread_mapping ();
+
+#endif
diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..139dd98
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,179 @@
+#include "nethogs.cpp"
+
+static void versiondisplay(void)
+{
+	std::cerr << version << "\n";
+}
+
+static void help(void)
+{
+	//std::cerr << "usage: nethogs [-V] [-b] [-d seconds] [-t] [-p] [-f (eth|ppp))] [device [device [device ...]]]\n";
+	std::cerr << "usage: nethogs [-V] [-b] [-d seconds] [-t] [-p] [device [device [device ...]]]\n";
+	std::cerr << "		-V : prints version.\n";
+	std::cerr << "		-d : delay for update refresh rate in seconds. default is 1.\n";
+	std::cerr << "		-t : tracemode.\n";
+	//std::cerr << "		-f : format of packets on interface, default is eth.\n";
+	std::cerr << "		-b : bughunt mode - implies tracemode.\n";
+	std::cerr << "		-p : sniff in promiscious mode (not recommended).\n";
+	std::cerr << "		device : device(s) to monitor. default is eth0\n";
+	std::cerr << std::endl;
+	std::cerr << "When nethogs is running, press:\n";
+	std::cerr << " q: quit\n";
+	std::cerr << " m: switch between total and kb/s mode\n";
+}
+
+int main (int argc, char** argv)
+{
+	process_init();
+
+	device * devices = NULL;
+	//dp_link_type linktype = dp_link_ethernet;
+	int promisc = 0;
+
+	int opt;
+	while ((opt = getopt(argc, argv, "Vhbtpd:")) != -1) {
+		switch(opt) {
+			case 'V':
+				versiondisplay();
+				exit(0);
+			case 'h':
+				help();
+				exit(0);
+			case 'b':
+				bughuntmode = true;
+				tracemode = true;
+				break;
+			case 't':
+				tracemode = true;
+				break;
+			case 'p':
+				promisc = 1;
+				break;
+			case 'd':
+				refreshdelay=atoi(optarg);
+				break;
+			/*
+			case 'f':
+				argv++;
+				if (strcmp (optarg, "ppp") == 0)
+					linktype = dp_link_ppp;
+				else if (strcmp (optarg, "eth") == 0)
+					linktype = dp_link_ethernet;
+				}
+				break;
+			*/
+			default:
+				help();
+				exit(EXIT_FAILURE);
+		}
+	}
+
+	while (optind < argc) {
+		devices = new device (strdup(argv[optind++]), devices);
+	}
+
+	if (devices == NULL)
+	{
+		devices = determine_default_device();
+	}
+
+	if ((!tracemode) && (!DEBUG)){
+		init_ui();
+	}
+
+	if (NEEDROOT && (getuid() != 0))
+		forceExit(false, "You need to be root to run NetHogs!");
+
+	char errbuf[PCAP_ERRBUF_SIZE];
+
+	handle * handles = NULL;
+	device * current_dev = devices;
+	while (current_dev != NULL) {
+		getLocal(current_dev->name, tracemode);
+		if ((!tracemode) && (!DEBUG)){
+			//caption->append(current_dev->name);
+			//caption->append(" ");
+		}
+
+		dp_handle * newhandle = dp_open_live(current_dev->name, BUFSIZ, promisc, 100, errbuf);
+		if (newhandle != NULL)
+		{
+			dp_addcb (newhandle, dp_packet_ip, process_ip);
+			dp_addcb (newhandle, dp_packet_ip6, process_ip6);
+			dp_addcb (newhandle, dp_packet_tcp, process_tcp);
+			dp_addcb (newhandle, dp_packet_udp, process_udp);
+
+			/* The following code solves sf.net bug 1019381, but is only available
+			 * in newer versions (from 0.8 it seems) of libpcap
+			 *
+			 * update: version 0.7.2, which is in debian stable now, should be ok
+			 * also.
+			 */
+			if (dp_setnonblock (newhandle, 1, errbuf) == -1)
+			{
+				fprintf(stderr, "Error putting libpcap in nonblocking mode\n");
+			}
+			handles = new handle (newhandle, current_dev->name, handles);
+		}
+		else
+		{
+			fprintf(stderr, "Error opening handler for device %s\n", current_dev->name);
+		}
+
+		current_dev = current_dev->next;
+	}
+
+	signal (SIGALRM, &alarm_cb);
+	signal (SIGINT, &quit_cb);
+	alarm (refreshdelay);
+
+	fprintf(stderr, "Waiting for first packet to arrive (see sourceforge.net bug 1019381)\n");
+
+	// Main loop:
+	//
+	//  Walks though the 'handles' list, which contains handles opened in non-blocking mode.
+	//  This causes the CPU utilisation to go up to 100%. This is tricky:
+	while (1)
+	{
+		bool packets_read = false;
+
+		handle * current_handle = handles;
+		while (current_handle != NULL)
+		{
+			struct dpargs * userdata = (dpargs *) malloc (sizeof (struct dpargs));
+			userdata->sa_family = AF_UNSPEC;
+			currentdevice = current_handle->devicename;
+			int retval = dp_dispatch (current_handle->content, -1, (u_char *)userdata, sizeof (struct dpargs));
+			if (retval == -1 || retval == -2)
+			{
+				std::cerr << "Error dispatching" << std::endl;
+			}
+			else if (retval != 0)
+			{
+				packets_read = true;
+			}
+			free (userdata);
+			current_handle = current_handle->next;
+		}
+
+		if ((!DEBUG)&&(!tracemode))
+		{
+			// handle user input
+			ui_tick();
+		}
+
+		if (needrefresh)
+		{
+			do_refresh();
+			needrefresh = false;
+		}
+
+		// If no packets were read at all this iteration, pause to prevent 100%
+		// CPU utilisation;
+		if (!packets_read)
+		{
+			usleep(100);
+		}
+	}
+}
+
diff --git a/nethogs.cpp b/nethogs.cpp
index 53ff9ce..a1920fb 100644
--- a/nethogs.cpp
+++ b/nethogs.cpp
@@ -106,6 +106,11 @@ struct dpargs {
 	in6_addr ip6_dst;
 };
 
+const char* getVersion()
+{
+	return version;
+}
+
 int process_tcp (u_char * userdata, const dp_header * header, const u_char * m_packet) {
 	struct dpargs * args = (struct dpargs *) userdata;
 	struct tcphdr * tcp = (struct tcphdr *) m_packet;
@@ -222,7 +227,7 @@ void quit_cb (int /* i */)
 	exit(0);
 }
 
-void forceExit(const char *msg, int errcode, ...)
+void forceExit(bool success, const char *msg, ...)
 {
 	if ((!tracemode)&&(!DEBUG)){
 		exit_ui();
@@ -234,30 +239,10 @@ void forceExit(const char *msg, int errcode, ...)
 	va_end(argp);
 	std::cerr << std::endl;
 
-    exit(errcode);
-}
-
-static void versiondisplay(void)
-{
-	std::cerr << version << "\n";
-}
-
-static void help(void)
-{
-	//std::cerr << "usage: nethogs [-V] [-b] [-d seconds] [-t] [-p] [-f (eth|ppp))] [device [device [device ...]]]\n";
-	std::cerr << "usage: nethogs [-V] [-b] [-d seconds] [-t] [-p] [device [device [device ...]]]\n";
-	std::cerr << "		-V : prints version.\n";
-	std::cerr << "		-d : delay for update refresh rate in seconds. default is 1.\n";
-	std::cerr << "		-t : tracemode.\n";
-	//std::cerr << "		-f : format of packets on interface, default is eth.\n";
-	std::cerr << "		-b : bughunt mode - implies tracemode.\n";
-	std::cerr << "		-p : sniff in promiscious mode (not recommended).\n";
-	std::cerr << "		device : device(s) to monitor. default is eth0\n";
-	std::cerr << std::endl;
-	std::cerr << "When nethogs is running, press:\n";
-	std::cerr << " q: quit\n";
-	std::cerr << " m: switch between total and kb/s mode\n";
-
+	if (success)
+		exit(EXIT_SUCCESS);
+	else
+		exit(EXIT_FAILURE);
 }
 
 class handle {
@@ -271,158 +256,3 @@ public:
 	handle * next;
 };
 
-int main (int argc, char** argv)
-{
-	process_init();
-
-	device * devices = NULL;
-	//dp_link_type linktype = dp_link_ethernet;
-	int promisc = 0;
-
-	int opt;
-	while ((opt = getopt(argc, argv, "Vhbtpd:")) != -1) {
-		switch(opt) {
-			case 'V':
-				versiondisplay();
-				exit(0);
-			case 'h':
-				help();
-				exit(0);
-			case 'b':
-				bughuntmode = true;
-				tracemode = true;
-				break;
-			case 't':
-				tracemode = true;
-				break;
-			case 'p':
-				promisc = 1;
-				break;
-			case 'd':
-				refreshdelay=atoi(optarg);
-				break;
-			/*
-			case 'f':
-				argv++;
-				if (strcmp (optarg, "ppp") == 0)
-					linktype = dp_link_ppp;
-				else if (strcmp (optarg, "eth") == 0)
-					linktype = dp_link_ethernet;
-				}
-				break;
-			*/
-			default:
-				help();
-				exit(EXIT_FAILURE);
-		}
-	}
-
-	while (optind < argc) {
-		devices = new device (strdup(argv[optind++]), devices);
-	}
-
-	if (devices == NULL)
-	{
-		devices = determine_default_device();
-	}
-
-	if ((!tracemode) && (!DEBUG)){
-		init_ui();
-	}
-
-	if (NEEDROOT && (getuid() != 0))
-		forceExit("You need to be root to run NetHogs!", -2);
-
-	char errbuf[PCAP_ERRBUF_SIZE];
-
-	handle * handles = NULL;
-	device * current_dev = devices;
-	while (current_dev != NULL) {
-		getLocal(current_dev->name, tracemode);
-		if ((!tracemode) && (!DEBUG)){
-			//caption->append(current_dev->name);
-			//caption->append(" ");
-		}
-
-		dp_handle * newhandle = dp_open_live(current_dev->name, BUFSIZ, promisc, 100, errbuf);
-		if (newhandle != NULL)
-		{
-			dp_addcb (newhandle, dp_packet_ip, process_ip);
-			dp_addcb (newhandle, dp_packet_ip6, process_ip6);
-			dp_addcb (newhandle, dp_packet_tcp, process_tcp);
-			dp_addcb (newhandle, dp_packet_udp, process_udp);
-
-			/* The following code solves sf.net bug 1019381, but is only available
-			 * in newer versions (from 0.8 it seems) of libpcap
-			 *
-			 * update: version 0.7.2, which is in debian stable now, should be ok
-			 * also.
-			 */
-			if (dp_setnonblock (newhandle, 1, errbuf) == -1)
-			{
-				fprintf(stderr, "Error putting libpcap in nonblocking mode\n");
-			}
-			handles = new handle (newhandle, current_dev->name, handles);
-		}
-		else
-		{
-			fprintf(stderr, "Error opening handler for device %s\n", current_dev->name);
-		}
-
-		current_dev = current_dev->next;
-	}
-
-	signal (SIGALRM, &alarm_cb);
-	signal (SIGINT, &quit_cb);
-	alarm (refreshdelay);
-
-	fprintf(stderr, "Waiting for first packet to arrive (see sourceforge.net bug 1019381)\n");
-
-	// Main loop:
-	//
-	//  Walks though the 'handles' list, which contains handles opened in non-blocking mode.
-	//  This causes the CPU utilisation to go up to 100%. This is tricky:
-	while (1)
-	{
-		bool packets_read = false;
-
-		handle * current_handle = handles;
-		while (current_handle != NULL)
-		{
-			struct dpargs * userdata = (dpargs *) malloc (sizeof (struct dpargs));
-			userdata->sa_family = AF_UNSPEC;
-			currentdevice = current_handle->devicename;
-			int retval = dp_dispatch (current_handle->content, -1, (u_char *)userdata, sizeof (struct dpargs));
-			if (retval == -1 || retval == -2)
-			{
-				std::cerr << "Error dispatching" << std::endl;
-			}
-			else if (retval != 0)
-			{
-				packets_read = true;
-			}
-			free (userdata);
-			current_handle = current_handle->next;
-		}
-
-		if ((!DEBUG)&&(!tracemode))
-		{
-			// handle user input
-			ui_tick();
-		}
-
-		if (needrefresh)
-		{
-			do_refresh();
-			needrefresh = false;
-		}
-
-		// If no packets were read at all this iteration, pause to prevent 100%
-		// CPU utilisation;
-		if (!packets_read)
-		{
-			usleep(100);
-		}
-	}
-}
-
diff --git a/nethogs.h b/nethogs.h
index a39d99f..cbca93b 100644
--- a/nethogs.h
+++ b/nethogs.h
@@ -63,7 +63,9 @@
 
 #define PROGNAME_WIDTH 512
 
-void forceExit(const char *msg, int errcode, ...);
+#define NORETURN __attribute__ ((__noreturn__))
+
+void forceExit(bool success, const char *msg, ...) NORETURN;
 
 class local_addr {
 public:
@@ -128,4 +130,6 @@ private:
 
 void quit_cb (int i);
 
+const char* getVersion();
+
 #endif
diff --git a/packet.cpp b/packet.cpp
index 36e19e1..fa36838 100644
--- a/packet.cpp
+++ b/packet.cpp
@@ -60,13 +60,14 @@ void getLocal (const char *device, bool tracemode)
 	struct ifreq iFreq;
 	struct sockaddr_in *saddr;
 
-	if((sock=socket(AF_INET, SOCK_RAW, htons(0x0806)))<0){
-		forceExit("creating socket failed while establishing local IP - are you root?", -3);
-	}
+	if((sock=socket(AF_INET, SOCK_RAW, htons(0x0806)))<0)
+		forceExit(false, "creating socket failed while establishing local IP - are you root?");
+
 	strcpy(iFreq.ifr_name, device);
-	if(ioctl(sock, SIOCGIFADDR, &iFreq)<0){
-		forceExit("ioctl failed while establishing local IP for selected device %s. You may specify the device on the command line.", -4, device);
-	}
+
+	if(ioctl(sock, SIOCGIFADDR, &iFreq)<0)
+		forceExit(false, "ioctl failed while establishing local IP for selected device %s. You may specify the device on the command line.", device);
+
 	saddr=(struct sockaddr_in*)&iFreq.ifr_addr;
 	local_addrs = new local_addr (saddr->sin_addr.s_addr, local_addrs);