some 'const' specifications, putting the code to determine the default device

in its own file

Makefile

@@ -13,7 +13,7 @@ all: nethogs decpcap_test
 
 CFLAGS=-g -Wall -Wextra
 #CFLAGS=-O2
-OBJS=packet.o connection.o process.o refresh.o decpcap.o cui.o inode2prog.o conninode.o
+OBJS=packet.o connection.o process.o refresh.o decpcap.o cui.o inode2prog.o conninode.o devices.o
 .PHONY: tgz
 
 tgz: clean
@@ -53,6 +53,8 @@ inode2prog.o: inode2prog.cpp inode2prog.h nethogs.h
 	$(CXX) $(CFLAGS) -c inode2prog.cpp
 conninode.o: conninode.cpp nethogs.h conninode.h
 	$(CXX) $(CFLAGS) -c conninode.cpp
+#devices.o: devices.cpp devices.h
+#	$(CXX) $(CFLAGS) -c devices.cpp
 cui.o: cui.cpp cui.h nethogs.h
 	$(CXX) $(CFLAGS) -c cui.cpp -DVERSION=\"$(VERSION)\" -DSUBVERSION=\"$(SUBVERSION)\" -DMINORVERSION=\"$(MINORVERSION)\"
 

decpcap.c

@@ -55,7 +55,7 @@ struct dp_handle * dp_open_offline(char * fname, char * ebuf)
 	return dp_fillhandle(temp);
 }
 
-struct dp_handle * dp_open_live(char * device, int snaplen, int promisc, int to_ms, char * ebuf)
+struct dp_handle * dp_open_live(const char * device, int snaplen, int promisc, int to_ms, const char * ebuf)
 {
 	pcap_t * temp = pcap_open_live(device, snaplen, promisc, to_ms, ebuf); 
 

decpcap.h

@@ -40,7 +40,7 @@ struct dp_handle {
 
 /* functions to set up a handle (which is basically just a pcap handle) */
 
-struct dp_handle * dp_open_live(char * device, int snaplen, int promisc, int to_ms, char * ebuf);
+struct dp_handle * dp_open_live(const char * device, int snaplen, int promisc, int to_ms, const char * ebuf);
 struct dp_handle * dp_open_offline(char * fname, char * ebuf);
 
 /* functions to add callbacks */

decpcap_test.cpp

@@ -4,7 +4,7 @@ extern "C" {
 	#include "decpcap.h"
 }
 
-int process_tcp (u_char * userdata, const dp_header * header, const u_char * m_packet) {
+int process_tcp (u_char * /* userdata */, const dp_header * /* header */, const u_char * /* m_packet */) {
 	std::cout << "Callback for processing TCP packet called" << std::endl;
 	return 0;
 }

devices.cpp

@@ -0,0 +1,7 @@
+#include "devices.h"
+
+device * determine_default_device()
+{
+	return new device("eth0");
+}
+

devices.h

@@ -0,0 +1,13 @@
+#include <cstddef> // NULL
+
+class device {
+public:
+	device (const char * m_name, device * m_next = NULL) 
+	{
+		name = m_name; next = m_next;
+	}
+	const char * name;
+	device * next;
+};
+
+device * determine_default_device();

nethogs.cpp

@@ -28,6 +28,7 @@ extern "C" {
 #include "connection.h"
 #include "process.h"
 #include "refresh.h"
+#include "devices.h"
 
 extern Process * unknownudp;
 
@@ -39,7 +40,7 @@ bool needrefresh = true;
 //dp_link_type linktype = dp_link_ethernet;
 const char version[] = " version " VERSION "." SUBVERSION "." MINORVERSION;
 
-char * currentdevice = NULL;
+const char * currentdevice = NULL;
 
 timeval curtime;
 
@@ -172,7 +173,7 @@ int process_udp (u_char * userdata, const dp_header * header, const u_char * m_p
 	return true;
 }
 
-int process_ip (u_char * userdata, const dp_header * header, const u_char * m_packet) {
+int process_ip (u_char * userdata, const dp_header * /* header */, const u_char * m_packet) {
 	struct dpargs * args = (struct dpargs *) userdata;
 	struct ip * ip = (struct ip *) m_packet;
 	args->sa_family = AF_INET;
@@ -183,7 +184,7 @@ int process_ip (u_char * userdata, const dp_header * header, const u_char * m_pa
 	return false;
 }
 
-int process_ip6 (u_char * userdata, const dp_header * header, const u_char * m_packet) {
+int process_ip6 (u_char * userdata, const dp_header * /* header */, const u_char * m_packet) {
 	struct dpargs * args = (struct dpargs *) userdata;
 	const struct ip6_hdr * ip6 = (struct ip6_hdr *) m_packet;
 	args->sa_family = AF_INET6;
@@ -194,7 +195,7 @@ int process_ip6 (u_char * userdata, const dp_header * header, const u_char * m_p
 	return false;
 }
 
-void quit_cb (int i)
+void quit_cb (int /* i */)
 {
 	procclean();
 	if ((!tracemode) && (!DEBUG))
@@ -240,24 +241,14 @@ static void help(void)
 
 }
 
-class device {
-public:
-	device (char * m_name, device * m_next = NULL)
-	{
-		name = m_name; next = m_next;
-	}
-	char * name;
-	device * next;
-};
-
 class handle {
 public:
-	handle (dp_handle * m_handle, char * m_devicename = NULL,
+	handle (dp_handle * m_handle, const char * m_devicename = NULL,
 			handle * m_next = NULL) {
 		content = m_handle; next = m_next; devicename = m_devicename;
 	}
 	dp_handle * content;
-	char * devicename;
+	const char * devicename;
 	handle * next;
 };
 
@@ -313,7 +304,7 @@ int main (int argc, char** argv)
 
 	if (devices == NULL)
 	{
-		devices = new device (strdup("eth0"));
+		devices = determine_default_device();
 	}
 
 	if ((!tracemode) && (!DEBUG)){

process.cpp

@@ -174,7 +174,7 @@ void check_all_procs ()
  * if the inode is not associated with any PID, return the unknown process
  * if the process is not yet in the proclist, add it
  */
-Process * getProcess (unsigned long inode, char * devicename)
+Process * getProcess (unsigned long inode, const char * devicename)
 {
 	struct prg_node * node = findPID(inode);
 	
@@ -232,7 +232,7 @@ Process * getProcess (unsigned long inode, char * devicename)
  * is made. If no process can be found even then, it's added to the 
  * 'unknown' process.
  */
-Process * getProcess (Connection * connection, char * devicename)
+Process * getProcess (Connection * connection, const char * devicename)
 {
 	unsigned long inode = conninode[connection->refpacket->gethashstring()];
 

process.h

@@ -109,7 +109,7 @@ private:
 	Process * val;
 };
 
-Process * getProcess (Connection * connection, char * devicename = NULL);
+Process * getProcess (Connection * connection, const char * devicename = NULL);
 
 void process_init ();