diff --git a/src/input/Manager.cc b/src/input/Manager.cc
index 43346f7d0f..2ea60a89cb 100644
--- a/src/input/Manager.cc
+++ b/src/input/Manager.cc
@@ -166,13 +166,13 @@ Manager::TableStream::~TableStream()
 	if ( rtype ) // can be 0 for sets
 		Unref(rtype);
 
-	if ( currDict != 0 )
+	if ( currDict )
 		{
 		currDict->Clear();
 		delete currDict;
 		}
 
-	if ( lastDict != 0 )
+	if ( lastDict )
 		{
 		lastDict->Clear();;
 		delete lastDict;
@@ -211,7 +211,7 @@ ReaderBackend* Manager::CreateBackend(ReaderFrontend* frontend, EnumVal* tag)
 	if ( ! c )
 		{
 		reporter->Error("The reader that was requested was not found and could not be initialized.");
-		return 0;
+		return nullptr;
 		}
 
 	ReaderBackend* backend = (*c->Factory())(frontend);
@@ -234,8 +234,7 @@ bool Manager::CreateStream(Stream* info, RecordVal* description)
 
 	string name = description->Lookup("name", true)->AsString()->CheckString();
 
-	Stream *i = FindStream(name);
-	if ( i != 0 )
+	if ( Stream *i = FindStream(name) )
 		{
 		reporter->Error("Trying create already existing input stream %s",
 				name.c_str());
@@ -551,7 +550,7 @@ bool Manager::CreateTableStream(RecordVal* fval)
 		}
 
 	auto event_val = fval->Lookup("ev", true);
-	Func* event = event_val ? event_val->AsFunc() : 0;
+	Func* event = event_val ? event_val->AsFunc() : nullptr;
 
 	if ( event )
 		{
@@ -672,13 +671,13 @@ bool Manager::CreateTableStream(RecordVal* fval)
 	for ( unsigned int i = 0; i < fieldsV.size(); i++ )
 		fields[i] = fieldsV[i];
 
-	stream->pred = pred ? pred->AsFunc() : 0;
+	stream->pred = pred ? pred->AsFunc() : nullptr;
 	stream->num_idx_fields = idxfields;
 	stream->num_val_fields = valfields;
 	stream->tab = dst.release()->AsTableVal();
 	stream->rtype = val.release();
 	stream->itype = idx->Ref()->AsRecordType();
-	stream->event = event ? event_registry->Lookup(event->Name()) : 0;
+	stream->event = event ? event_registry->Lookup(event->Name()) : nullptr;
 	stream->error_event = error_event ? event_registry->Lookup(error_event->Name()) : nullptr;
 	stream->currDict = new PDict<InputHash>;
 	stream->currDict->SetDeleteFunc(input_hash_delete_func);
@@ -769,7 +768,7 @@ bool Manager::CreateAnalysisStream(RecordVal* fval)
 
 	// reader takes in a byte stream as the only field
 	Field** fields = new Field*[1];
-	fields[0] = new Field("bytestream", 0, TYPE_STRING, TYPE_VOID, false);
+	fields[0] = new Field("bytestream", nullptr, TYPE_STRING, TYPE_VOID, false);
 	stream->reader->Init(1, fields);
 
 	readers[stream->reader] = stream;
@@ -833,7 +832,7 @@ bool Manager::IsCompatibleType(BroType* t, bool atomic_only)
 
 bool Manager::RemoveStream(Stream *i)
 	{
-	if ( i == 0 )
+	if ( i == nullptr )
 		return false; // not found
 
 	if ( i->removed )
@@ -868,7 +867,7 @@ bool Manager::RemoveStreamContinuation(ReaderFrontend* reader)
 	{
 	Stream *i = FindStream(reader);
 
-	if ( i == 0 )
+	if ( i == nullptr )
 		{
 		reporter->Error("Stream not found in RemoveStreamContinuation");
 		return false;
@@ -934,7 +933,7 @@ bool Manager::UnrollRecordType(vector<Field*> *fields, const RecordType *rec,
 		else
 			{
 			string name = nameprepend + rec->FieldName(i);
-			const char* secondary = 0;
+			const char* secondary = nullptr;
 			IntrusivePtr<Val> c;
 			TypeTag ty = rec->FieldType(i)->Tag();
 			TypeTag st = TYPE_VOID;
@@ -951,7 +950,7 @@ bool Manager::UnrollRecordType(vector<Field*> *fields, const RecordType *rec,
 				{
 				// we have an annotation for the second column
 
-				c = rec->FieldDecl(i)->FindAttr(ATTR_TYPE_COLUMN)->AttrExpr()->Eval(0);
+				c = rec->FieldDecl(i)->FindAttr(ATTR_TYPE_COLUMN)->AttrExpr()->Eval(nullptr);
 
 				assert(c);
 				assert(c->Type()->Tag() == TYPE_STRING);
@@ -973,7 +972,7 @@ bool Manager::UnrollRecordType(vector<Field*> *fields, const RecordType *rec,
 bool Manager::ForceUpdate(const string &name)
 	{
 	Stream *i = FindStream(name);
-	if ( i == 0 )
+	if ( i == nullptr )
 		{
 		reporter->Error("Stream %s not found", name.c_str());
 		return false;
@@ -1057,7 +1056,7 @@ Val* Manager::ValueToIndexVal(const Stream* i, int num_fields, const RecordType
 void Manager::SendEntry(ReaderFrontend* reader, Value* *vals)
 	{
 	Stream *i = FindStream(reader);
-	if ( i == 0 )
+	if ( i == nullptr )
 		{
 		reporter->InternalWarning("Unknown reader %s in SendEntry",
 		                          reader->Name());
@@ -1101,7 +1100,7 @@ int Manager::SendEntryTable(Stream* i, const Value* const *vals)
 
 	HashKey* idxhash = HashValues(stream->num_idx_fields, vals);
 
-	if ( idxhash == 0 )
+	if ( idxhash == nullptr )
 		{
 		Warning(i, "Could not hash line. Ignoring");
 		return stream->num_val_fields + stream->num_idx_fields;
@@ -1110,21 +1109,20 @@ int Manager::SendEntryTable(Stream* i, const Value* const *vals)
 	hash_t valhash = 0;
 	if ( stream->num_val_fields > 0 )
 		{
-		HashKey* valhashkey = HashValues(stream->num_val_fields, vals+stream->num_idx_fields);
-		if ( valhashkey == 0 )
-			{
-			// empty line. index, but no values.
-			// hence we also have no hash value...
-			}
-		else
+		if ( HashKey* valhashkey = HashValues(stream->num_val_fields, vals+stream->num_idx_fields) )
 			{
 			valhash = valhashkey->Hash();
 			delete(valhashkey);
 			}
+		else
+			{
+			// empty line. index, but no values.
+			// hence we also have no hash value...
+			}
 		}
 
 	InputHash *h = stream->lastDict->Lookup(idxhash);
-	if ( h != 0 )
+	if ( h )
 		{
 		// seen before
 		if ( stream->num_val_fields == 0 || h->valhash == valhash )
@@ -1148,14 +1146,14 @@ int Manager::SendEntryTable(Stream* i, const Value* const *vals)
 		}
 
 	Val* valval;
-	RecordVal* predidx = 0;
+	RecordVal* predidx = nullptr;
 
 	int position = stream->num_idx_fields;
 
 	bool convert_error = false; // this will be set to true by ValueTo* on Error
 
 	if ( stream->num_val_fields == 0 )
-		valval = 0;
+		valval = nullptr;
 
 	else if ( stream->num_val_fields == 1 && !stream->want_record )
 		valval = ValueToVal(i, vals[position], stream->rtype->FieldType(0), convert_error);
@@ -1213,10 +1211,10 @@ int Manager::SendEntryTable(Stream* i, const Value* const *vals)
 
 	// now we don't need h anymore - if we are here, the entry is updated and a new h is created.
 	delete h;
-	h = 0;
+	h = nullptr;
 
 	Val* idxval;
-	if ( predidx != 0 )
+	if ( predidx != nullptr )
 		{
 		idxval = RecordValToIndexVal(predidx);
 		// I think there is an unref missing here. But if I insert is, it crashes :)
@@ -1256,7 +1254,7 @@ int Manager::SendEntryTable(Stream* i, const Value* const *vals)
 	stream->tab->Assign(idxval, k, valval);
 	Unref(idxval); // asssign does not consume idxval.
 
-	if ( predidx != 0 )
+	if ( predidx != nullptr )
 		Unref(predidx);
 
 	auto prev = stream->currDict->Insert(idxhash, ih);
@@ -1279,7 +1277,7 @@ int Manager::SendEntryTable(Stream* i, const Value* const *vals)
 			{ // in case of update send back the old value.
 			assert ( stream->num_val_fields > 0 );
 			ev = BifType::Enum::Input::Event->GetVal(BifEnum::Input::EVENT_CHANGED).release();
-			assert ( oldval != 0 );
+			assert ( oldval != nullptr );
 			SendEvent(stream->event, 4, stream->description->Ref(), ev, predidx, oldval.release());
 			}
 		else
@@ -1302,7 +1300,7 @@ void Manager::EndCurrentSend(ReaderFrontend* reader)
 	{
 	Stream *i = FindStream(reader);
 
-	if ( i == 0 )
+	if ( i == nullptr )
 		{
 		reporter->InternalWarning("Unknown reader %s in EndCurrentSend",
 		                          reader->Name());
@@ -1336,8 +1334,8 @@ void Manager::EndCurrentSend(ReaderFrontend* reader)
 		{
 		IntrusivePtr<Val> val;
 
-		Val* predidx = 0;
-		EnumVal* ev = 0;
+		Val* predidx = nullptr;
+		EnumVal* ev = nullptr;
 		int startpos = 0;
 
 		if ( stream->pred || stream->event )
@@ -1345,7 +1343,7 @@ void Manager::EndCurrentSend(ReaderFrontend* reader)
 			auto idx = stream->tab->RecoverIndex(ih->idxkey);
 			assert(idx != nullptr);
 			val = stream->tab->Lookup(idx.get());
-			assert(val != 0);
+			assert(val != nullptr);
 			predidx = ListValToRecordVal(idx.get(), stream->itype, &startpos);
 			ev = BifType::Enum::Input::Event->GetVal(BifEnum::Input::EVENT_REMOVED).release();
 			}
@@ -1409,7 +1407,7 @@ void Manager::SendEndOfData(ReaderFrontend* reader)
 	{
 	Stream *i = FindStream(reader);
 
-	if ( i == 0 )
+	if ( i == nullptr )
 		{
 		reporter->InternalWarning("Unknown reader %s in SendEndOfData",
 		                          reader->Name());
@@ -1436,7 +1434,7 @@ void Manager::SendEndOfData(const Stream *i)
 void Manager::Put(ReaderFrontend* reader, Value* *vals)
 	{
 	Stream *i = FindStream(reader);
-	if ( i == 0 )
+	if ( i == nullptr )
 		{
 		reporter->InternalWarning("Unknown reader %s in Put", reader->Name());
 		return;
@@ -1500,7 +1498,7 @@ int Manager::SendEventStreamEvent(Stream* i, EnumVal* type, const Value* const *
 		{
 		for ( int j = 0; j < stream->fields->NumFields(); j++)
 			{
-			Val* val = 0;
+			Val* val = nullptr;
 
 			if ( stream->fields->FieldType(j)->Tag() == TYPE_RECORD )
 				val = ValueToRecordVal(i, vals,
@@ -1544,7 +1542,7 @@ int Manager::PutTable(Stream* i, const Value* const *vals)
 	int position = stream->num_idx_fields;
 
 	if ( stream->num_val_fields == 0 )
-		valval = 0;
+		valval = nullptr;
 
 	else if ( stream->num_val_fields == 1 && stream->want_record == 0 )
 		valval = ValueToVal(i, vals[position], stream->rtype->FieldType(0), convert_error);
@@ -1571,7 +1569,7 @@ int Manager::PutTable(Stream* i, const Value* const *vals)
 			oldval = stream->tab->Lookup(idxval, false);
 			}
 
-		if ( oldval != 0 )
+		if ( oldval != nullptr )
 			{
 			// it is an update
 			updated = true;
@@ -1633,7 +1631,7 @@ int Manager::PutTable(Stream* i, const Value* const *vals)
 					// in case of update send back the old value.
 					assert ( stream->num_val_fields > 0 );
 					ev = BifType::Enum::Input::Event->GetVal(BifEnum::Input::EVENT_CHANGED).release();
-					assert ( oldval != 0 );
+					assert ( oldval != nullptr );
 					SendEvent(stream->event, 4, stream->description->Ref(),
 					          ev, predidx, oldval.release());
 					}
@@ -1665,7 +1663,7 @@ int Manager::PutTable(Stream* i, const Value* const *vals)
 void Manager::Clear(ReaderFrontend* reader)
 	{
 	Stream *i = FindStream(reader);
-	if ( i == 0 )
+	if ( i == nullptr )
 		{
 		reporter->InternalWarning("Unknown reader %s in Clear",
 		                          reader->Name());
@@ -1687,7 +1685,7 @@ void Manager::Clear(ReaderFrontend* reader)
 bool Manager::Delete(ReaderFrontend* reader, Value* *vals)
 	{
 	Stream *i = FindStream(reader);
-	if ( i == 0 )
+	if ( i == nullptr )
 		{
 		reporter->InternalWarning("Unknown reader %s in Delete", reader->Name());
 		return false;
@@ -1701,7 +1699,7 @@ bool Manager::Delete(ReaderFrontend* reader, Value* *vals)
 		TableStream* stream = (TableStream*) i;
 		bool convert_error = false;
 		Val* idxval = ValueToIndexVal(i, stream->num_idx_fields, stream->itype, vals, convert_error);
-		assert(idxval != 0);
+		assert(idxval != nullptr);
 		readVals = stream->num_idx_fields + stream->num_val_fields;
 		bool streamresult = true;
 
@@ -1742,7 +1740,7 @@ bool Manager::Delete(ReaderFrontend* reader, Value* *vals)
 			if ( streamresult && stream->event )
 				{
 				Ref(idxval);
-				assert(val != 0);
+				assert(val != nullptr);
 				EnumVal* ev = BifType::Enum::Input::Event->GetVal(BifEnum::Input::EVENT_REMOVED).release();
 				SendEvent(stream->event, 4, stream->description->Ref(), ev, idxval, IntrusivePtr{val}.release());
 				}
@@ -1806,7 +1804,7 @@ bool Manager::CallPred(Func* pred_func, const int numvals, ...) const
 bool Manager::SendEvent(ReaderFrontend* reader, const string& name, const int num_vals, Value* *vals) const
 	{
 	Stream *i = FindStream(reader);
-	if ( i == 0 )
+	if ( i == nullptr )
 		{
 		reporter->InternalWarning("Unknown reader %s in SendEvent for event %s", reader->Name(), name.c_str());
 		delete_value_ptr_array(vals, num_vals);
@@ -1814,7 +1812,7 @@ bool Manager::SendEvent(ReaderFrontend* reader, const string& name, const int nu
 		}
 
 	EventHandler* handler = event_registry->Lookup(name);
-	if ( handler == 0 )
+	if ( handler == nullptr )
 		{
 		Warning(i, "Event %s not found", name.c_str());
 		delete_value_ptr_array(vals, num_vals);
@@ -1904,18 +1902,18 @@ void Manager::SendEvent(EventHandlerPtr ev, list<Val*> events) const
 // I / we could think about moving this functionality to val.cc
 RecordVal* Manager::ListValToRecordVal(ListVal* list, RecordType *request_type, int* position) const
 	{
-	assert(position != 0 ); // we need the pointer to point to data;
+	assert(position != nullptr); // we need the pointer to point to data;
 
 	RecordVal* rec = new RecordVal(request_type->AsRecordType());
 
-	assert(list != 0);
+	assert(list != nullptr);
 	int maxpos = list->Length();
 
 	for ( int i = 0; i < request_type->NumFields(); i++ )
 		{
 		assert ( (*position) <= maxpos );
 
-		Val* fieldVal = 0;
+		Val* fieldVal = nullptr;
 		if ( request_type->FieldType(i)->Tag() == TYPE_RECORD )
 			fieldVal = ListValToRecordVal(list, request_type->FieldType(i)->AsRecordType(), position);
 		else
@@ -1934,12 +1932,12 @@ RecordVal* Manager::ListValToRecordVal(ListVal* list, RecordType *request_type,
 RecordVal* Manager::ValueToRecordVal(const Stream* stream, const Value* const *vals,
 	                             RecordType *request_type, int* position, bool& have_error) const
 	{
-	assert(position != 0); // we need the pointer to point to data.
+	assert(position != nullptr); // we need the pointer to point to data.
 
 	RecordVal* rec = new RecordVal(request_type->AsRecordType());
 	for ( int i = 0; i < request_type->NumFields(); i++ )
 		{
-		Val* fieldVal = 0;
+		Val* fieldVal = nullptr;
 		if ( request_type->FieldType(i)->Tag() == TYPE_RECORD )
 			fieldVal = ValueToRecordVal(stream, vals, request_type->FieldType(i)->AsRecordType(), position, have_error);
 		else if ( request_type->FieldType(i)->Tag() == TYPE_FILE ||
@@ -2215,7 +2213,7 @@ HashKey* Manager::HashValues(const int num_elements, const Value* const *vals) c
 	assert ( length >= num_elements );
 
 	if ( length == num_elements )
-		return NULL;
+		return nullptr;
 
 	int position = 0;
 	char *data = new char[length];
@@ -2285,7 +2283,7 @@ Val* Manager::ValueToVal(const Stream* i, const Value* val, BroType* request_typ
 
 	case TYPE_ADDR:
 		{
-		IPAddr* addr = 0;
+		IPAddr* addr = nullptr;
 		switch ( val->val.addr_val.family ) {
 		case IPv4:
 			addr = new IPAddr(val->val.addr_val.in.in4);
@@ -2344,7 +2342,7 @@ Val* Manager::ValueToVal(const Stream* i, const Value* val, BroType* request_typ
 			{
 			Val* assignval = ValueToVal(i, val->val.set_val.vals[j], type, have_error);
 
-			t->Assign(assignval, 0);
+			t->Assign(assignval, nullptr);
 			Unref(assignval); // index is not consumed by assign.
 			}
 
@@ -2395,7 +2393,7 @@ Val* Manager::ValueToVal(const Stream* i, const Value* val, BroType* request_typ
 	}
 
 	assert(false);
-	return NULL;
+	return nullptr;
 	}
 
 Val* Manager::ValueToVal(const Stream* i, const Value* val, bool& have_error) const
@@ -2433,7 +2431,7 @@ Val* Manager::ValueToVal(const Stream* i, const Value* val, bool& have_error) co
 
 	case TYPE_ADDR:
 		{
-		IPAddr* addr = 0;
+		IPAddr* addr = nullptr;
 		switch ( val->val.addr_val.family ) {
 		case IPv4:
 			addr = new IPAddr(val->val.addr_val.in.in4);
@@ -2526,7 +2524,7 @@ Val* Manager::ValueToVal(const Stream* i, const Value* val, bool& have_error) co
 			{
 			Val* assignval = ValueToVal(i, val->val.set_val.vals[j], have_error);
 
-			t->Assign(assignval, 0);
+			t->Assign(assignval, nullptr);
 			Unref(assignval); // index is not consumed by assign.
 			}
 
@@ -2593,7 +2591,7 @@ Val* Manager::ValueToVal(const Stream* i, const Value* val, bool& have_error) co
 	}
 
 	assert(false);
-	return NULL;
+	return nullptr;
 	}
 
 Manager::Stream* Manager::FindStream(const string &name) const
@@ -2604,7 +2602,7 @@ Manager::Stream* Manager::FindStream(const string &name) const
 			return (*s).second;
 		}
 
-	return 0;
+	return nullptr;
 	}
 
 Manager::Stream* Manager::FindStream(ReaderFrontend* reader) const
@@ -2613,7 +2611,7 @@ Manager::Stream* Manager::FindStream(ReaderFrontend* reader) const
 	if ( s != readers.end() )
 		return s->second;
 
-	return 0;
+	return nullptr;
 	}
 
 // Function is called on Bro shutdown.
diff --git a/src/input/ReaderBackend.cc b/src/input/ReaderBackend.cc
index 656743abb5..90050a6438 100644
--- a/src/input/ReaderBackend.cc
+++ b/src/input/ReaderBackend.cc
@@ -204,7 +204,7 @@ ReaderBackend::ReaderBackend(ReaderFrontend* arg_frontend) : MsgThread()
 	frontend = arg_frontend;
 	info = new ReaderInfo(frontend->Info());
 	num_fields = 0;
-	fields = 0;
+	fields = nullptr;
 
 	SetName(frontend->Name());
 	}
@@ -282,13 +282,13 @@ bool ReaderBackend::OnFinish(double network_time)
 	disabled = true; // frontend disables itself when it gets the Close-message.
 	SendOut(new ReaderClosedMessage(frontend));
 
-	if ( fields != 0 )
+	if ( fields )
 		{
 		for ( unsigned int i = 0; i < num_fields; i++ )
 			delete(fields[i]);
 
 		delete [] (fields);
-		fields = 0;
+		fields = nullptr;
 		}
 
 	return true;
diff --git a/src/input/ReaderBackend.h b/src/input/ReaderBackend.h
index 3219359f71..d158d0972c 100644
--- a/src/input/ReaderBackend.h
+++ b/src/input/ReaderBackend.h
@@ -104,15 +104,15 @@ public:
 
 		ReaderInfo()
 			{
-			source = 0;
-			name = 0;
+			source = nullptr;
+			name = nullptr;
 			mode = MODE_NONE;
 			}
 
 		ReaderInfo(const ReaderInfo& other)
 			{
-			source = other.source ? copy_string(other.source) : 0;
-			name = other.name ? copy_string(other.name) : 0;
+			source = other.source ? copy_string(other.source) : nullptr;
+			name = other.name ? copy_string(other.name) : nullptr;
 			mode = other.mode;
 
 			for ( config_map::const_iterator i = other.config.begin(); i != other.config.end(); i++ )
diff --git a/src/input/ReaderFrontend.cc b/src/input/ReaderFrontend.cc
index 898d4b30da..7fce36ee71 100644
--- a/src/input/ReaderFrontend.cc
+++ b/src/input/ReaderFrontend.cc
@@ -52,7 +52,7 @@ void ReaderFrontend::Stop()
 	if ( backend )
 		{
 		backend->SignalStop();
-		backend = 0; // Thread manager will clean it up once it finishes.
+		backend = nullptr; // Thread manager will clean it up once it finishes.
 		}
 	}
 
diff --git a/src/input/readers/ascii/Ascii.cc b/src/input/readers/ascii/Ascii.cc
index 2bf2cff996..d04fbe713d 100644
--- a/src/input/readers/ascii/Ascii.cc
+++ b/src/input/readers/ascii/Ascii.cc
@@ -396,7 +396,7 @@ bool Ascii::DoUpdate()
 
 			Value* val = formatter->ParseValue(stringfields[(*fit).position], (*fit).name, (*fit).type, (*fit).subtype);
 
-			if ( val == 0 )
+			if ( ! val )
 				{
 				Warning(Fmt("Could not convert line '%s' of %s to Val. Ignoring line.", line.c_str(), fname.c_str()));
 				error = true;
diff --git a/src/input/readers/benchmark/Benchmark.cc b/src/input/readers/benchmark/Benchmark.cc
index 49e989909c..32d57787c1 100644
--- a/src/input/readers/benchmark/Benchmark.cc
+++ b/src/input/readers/benchmark/Benchmark.cc
@@ -210,11 +210,11 @@ threading::Value* Benchmark::EntryToVal(TypeTag type, TypeTag subtype)
 		for ( unsigned int pos = 0; pos < length; pos++ )
 			{
 			Value* newval = EntryToVal(subtype, TYPE_ENUM);
-			if ( newval == 0 )
+			if ( newval == nullptr )
 				{
 				Error("Error while reading set");
 				delete val;
-				return 0;
+				return nullptr;
 				}
 			lvals[pos] = newval;
 			}
@@ -226,7 +226,7 @@ threading::Value* Benchmark::EntryToVal(TypeTag type, TypeTag subtype)
 	default:
 		Error(Fmt("unsupported field format %d", type));
 		delete val;
-		return 0;
+		return nullptr;
 	}
 
 	return val;
@@ -265,7 +265,7 @@ bool Benchmark::DoHeartbeat(double network_time, double current_time)
 
 			Update(); // call update and not DoUpdate, because update actually checks disabled.
 
-			SendEvent("HeartbeatDone", 0, 0);
+			SendEvent("HeartbeatDone", 0, nullptr);
 			break;
 
 		default:
diff --git a/src/input/readers/binary/Binary.cc b/src/input/readers/binary/Binary.cc
index 87c38d16aa..22a7121e13 100644
--- a/src/input/readers/binary/Binary.cc
+++ b/src/input/readers/binary/Binary.cc
@@ -14,7 +14,7 @@ using threading::Field;
 streamsize Binary::chunk_size = 0;
 
 Binary::Binary(ReaderFrontend *frontend)
-	: ReaderBackend(frontend), in(0), mtime(0), ino(0), firstrun(true)
+	: ReaderBackend(frontend), in(nullptr), mtime(0), ino(0), firstrun(true)
 	{
 	if ( ! chunk_size )
 		{
@@ -64,7 +64,7 @@ bool Binary::CloseInput()
 
 	in->close();
 	delete in;
-	in = 0;
+	in = nullptr;
 
 #ifdef DEBUG
 	Debug(DBG_INPUT, "Binary reader finished close");
@@ -76,7 +76,7 @@ bool Binary::CloseInput()
 bool Binary::DoInit(const ReaderInfo& info, int num_fields,
                     const Field* const* fields)
 	{
-	in = 0;
+	in = nullptr;
 	mtime = 0;
 	ino = 0;
 	firstrun = true;
@@ -158,7 +158,7 @@ streamsize Binary::GetChunk(char** chunk)
 	if ( ! bytes_read )
 		{
 		delete [] *chunk;
-		*chunk = 0;
+		*chunk = nullptr;
 		return 0;
 		}
 
@@ -231,7 +231,7 @@ bool Binary::DoUpdate()
 		}
 		}
 
-	char* chunk = 0;
+	char* chunk = nullptr;
 	streamsize size = 0;
 	while ( (size = GetChunk(&chunk)) )
 		{
diff --git a/src/input/readers/sqlite/SQLite.cc b/src/input/readers/sqlite/SQLite.cc
index 821e6cdd9a..e831db8c62 100644
--- a/src/input/readers/sqlite/SQLite.cc
+++ b/src/input/readers/sqlite/SQLite.cc
@@ -156,7 +156,7 @@ Value* SQLite::EntryToVal(sqlite3_stmt *st, const threading::Field *field, int p
 			{
 			Error("Invalid data type for boolean - expected Integer");
 			delete val;
-			return 0;
+			return nullptr;
 			}
 
 		int res = sqlite3_column_int(st, pos);
@@ -167,7 +167,7 @@ Value* SQLite::EntryToVal(sqlite3_stmt *st, const threading::Field *field, int p
 			{
 			Error(Fmt("Invalid value for boolean: %d", res));
 			delete val;
-			return 0;
+			return nullptr;
 			}
 		break;
 		}
@@ -240,7 +240,7 @@ Value* SQLite::EntryToVal(sqlite3_stmt *st, const threading::Field *field, int p
 	default:
 		Error(Fmt("unsupported field format %d", field->type));
 		delete val;
-		return 0;
+		return nullptr;
 	}
 
 	return val;
@@ -279,7 +279,7 @@ bool SQLite::DoUpdate()
 				mapping[j] = i;
 				}
 
-			if ( fields[j]->secondary_name != 0 && strcmp(fields[j]->secondary_name, name) == 0 )
+			if ( fields[j]->secondary_name != nullptr && strcmp(fields[j]->secondary_name, name) == 0 )
 				{
 				assert(fields[j]->type == TYPE_PORT);
 				if ( submapping[j] != -1 )
@@ -314,7 +314,7 @@ bool SQLite::DoUpdate()
 		for ( unsigned int j = 0; j < num_fields; ++j)
 			{
 			ofields[j] = EntryToVal(st, fields[j], mapping[j], submapping[j]);
-			if ( ofields[j] == 0 )
+			if ( ! ofields[j] )
 				{
 				for ( unsigned int k = 0; k < j; ++k )
 					delete ofields[k];
diff --git a/src/iosource/BPF_Program.cc b/src/iosource/BPF_Program.cc
index 8a97a6fc25..165b2fa2b2 100644
--- a/src/iosource/BPF_Program.cc
+++ b/src/iosource/BPF_Program.cc
@@ -143,7 +143,7 @@ bool BPF_Program::Compile(int snaplen, int linktype, const char* filter,
 
 bpf_program* BPF_Program::GetProgram()
 	{
-	return m_compiled ? &m_program : 0;
+	return m_compiled ? &m_program : nullptr;
 	}
 
 void BPF_Program::FreeCode()
diff --git a/src/iosource/BPF_Program.h b/src/iosource/BPF_Program.h
index de06e9d13a..0ff37bfd1f 100644
--- a/src/iosource/BPF_Program.h
+++ b/src/iosource/BPF_Program.h
@@ -22,14 +22,14 @@ public:
 	// Parameters are like in pcap_compile(). Returns true
 	// for successful compilation, false otherwise.
 	bool Compile(pcap_t* pcap, const char* filter, uint32_t netmask,
-		 char* errbuf = 0, unsigned int errbuf_len = 0,
+		 char* errbuf = nullptr, unsigned int errbuf_len = 0,
 		 bool optimize = true);
 
 	// Creates a BPF program when no pcap handle is around,
 	// similarly to pcap_compile_nopcap(). Parameters are
 	// similar. Returns true on success.
 	bool Compile(int snaplen, int linktype, const char* filter,
-		uint32_t netmask, char* errbuf = 0, unsigned int errbuf_len = 0,
+		uint32_t netmask, char* errbuf = nullptr, unsigned int errbuf_len = 0,
 		bool optimize = true);
 
 	// Returns true if this program currently contains compiled
diff --git a/src/iosource/Manager.cc b/src/iosource/Manager.cc
index 6bfa1ad420..217bdf0f8a 100644
--- a/src/iosource/Manager.cc
+++ b/src/iosource/Manager.cc
@@ -330,7 +330,7 @@ PktSrc* Manager::OpenPktSrc(const std::string& path, bool is_live)
 
 	// Find the component providing packet sources of the requested prefix.
 
-	PktSrcComponent* component = 0;
+	PktSrcComponent* component = nullptr;
 
 	std::list<PktSrcComponent*> all_components = plugin_mgr->Components<PktSrcComponent>();
 	for ( const auto& c : all_components )
@@ -372,7 +372,7 @@ PktDumper* Manager::OpenPktDumper(const string& path, bool append)
 
 	// Find the component providing packet dumpers of the requested prefix.
 
-	PktDumperComponent* component = 0;
+	PktDumperComponent* component = nullptr;
 
 	std::list<PktDumperComponent*> all_components = plugin_mgr->Components<PktDumperComponent>();
 	for ( const auto& c : all_components )
diff --git a/src/iosource/Packet.h b/src/iosource/Packet.h
index 4913514678..2da4836b7b 100644
--- a/src/iosource/Packet.h
+++ b/src/iosource/Packet.h
@@ -59,7 +59,7 @@ public:
 	Packet(int link_type, pkt_timeval *ts, uint32_t caplen,
 	       uint32_t len, const u_char *data, bool copy = false,
 	       std::string tag = std::string(""))
-	           : data(0), l2_src(0), l2_dst(0)
+	           : data(nullptr), l2_src(nullptr), l2_dst(nullptr)
 	       {
 	       Init(link_type, ts, caplen, len, data, copy, tag);
 	       }
@@ -67,10 +67,10 @@ public:
 	/**
 	 * Default constructor. For internal use only.
 	 */
-	Packet() : data(0), l2_src(0), l2_dst(0)
+	Packet() : data(nullptr), l2_src(nullptr), l2_dst(nullptr)
 		{
 		pkt_timeval ts = {0, 0};
-		Init(0, &ts, 0, 0, 0);
+		Init(0, &ts, 0, 0, nullptr);
 		}
 
 	/**
diff --git a/src/iosource/PktDumper.cc b/src/iosource/PktDumper.cc
index 9a49ccb6fb..f0d911b9b4 100644
--- a/src/iosource/PktDumper.cc
+++ b/src/iosource/PktDumper.cc
@@ -45,12 +45,12 @@ double PktDumper::OpenTime() const
 
 bool PktDumper::IsError() const
 	{
-	return errmsg.size();
+	return ! errmsg.empty();
 	}
 
 const char* PktDumper::ErrorMsg() const
 	{
-	return errmsg.size() ? errmsg.c_str() : 0;
+	return errmsg.size() ? errmsg.c_str() : nullptr;
 	}
 
 int PktDumper::HdrSize() const
diff --git a/src/iosource/PktSrc.cc b/src/iosource/PktSrc.cc
index 19bf1f3f52..53c2a747aa 100644
--- a/src/iosource/PktSrc.cc
+++ b/src/iosource/PktSrc.cc
@@ -51,7 +51,7 @@ const std::string& PktSrc::Path() const
 
 const char* PktSrc::ErrorMsg() const
 	{
-	return errbuf.size() ? errbuf.c_str() : 0;
+	return errbuf.size() ? errbuf.c_str() : nullptr;
 	}
 
 int PktSrc::LinkType() const
@@ -66,7 +66,7 @@ uint32_t PktSrc::Netmask() const
 
 bool PktSrc::IsError() const
 	{
-	return ErrorMsg();
+	return ! errbuf.empty();
 	}
 
 bool PktSrc::IsLive() const
@@ -153,7 +153,7 @@ void PktSrc::Info(const std::string& msg)
 
 void PktSrc::Weird(const std::string& msg, const Packet* p)
 	{
-	sessions->Weird(msg.c_str(), p, 0);
+	sessions->Weird(msg.c_str(), p, nullptr);
 	}
 
 void PktSrc::InternalError(const std::string& msg)
@@ -299,9 +299,9 @@ bool PktSrc::PrecompileBPFFilter(int index, const std::string& filter)
 BPF_Program* PktSrc::GetBPFFilter(int index)
 	{
 	if ( index < 0 )
-		return 0;
+		return nullptr;
 
-	return (static_cast<int>(filters.size()) > index ? filters[index] : 0);
+	return (static_cast<int>(filters.size()) > index ? filters[index] : nullptr);
 	}
 
 bool PktSrc::ApplyBPFFilter(int index, const struct pcap_pkthdr *hdr, const u_char *pkt)
diff --git a/src/iosource/pcap/Dumper.cc b/src/iosource/pcap/Dumper.cc
index e6e400477e..5bbf12dfa6 100644
--- a/src/iosource/pcap/Dumper.cc
+++ b/src/iosource/pcap/Dumper.cc
@@ -15,8 +15,8 @@ PcapDumper::PcapDumper(const std::string& path, bool arg_append)
 	{
 	append = arg_append;
 	props.path = path;
-	dumper = 0;
-	pd = 0;
+	dumper = nullptr;
+	pd = nullptr;
 	}
 
 PcapDumper::~PcapDumper()
@@ -93,8 +93,8 @@ void PcapDumper::Close()
 
 	pcap_dump_close(dumper);
 	pcap_close(pd);
-	dumper = 0;
-	pd = 0;
+	dumper = nullptr;
+	pd = nullptr;
 
 	Closed();
 	}
diff --git a/src/iosource/pcap/Source.h b/src/iosource/pcap/Source.h
index f32071cb99..24271b6613 100644
--- a/src/iosource/pcap/Source.h
+++ b/src/iosource/pcap/Source.h
@@ -33,7 +33,7 @@ protected:
 private:
 	void OpenLive();
 	void OpenOffline();
-	void PcapError(const char* where = 0);
+	void PcapError(const char* where = nullptr);
 
 	Properties props;
 	Stats stats;
diff --git a/src/logging/Manager.cc b/src/logging/Manager.cc
index d1af7e674c..b5f399f98f 100644
--- a/src/logging/Manager.cc
+++ b/src/logging/Manager.cc
@@ -147,7 +147,7 @@ WriterBackend* Manager::CreateBackend(WriterFrontend* frontend, EnumVal* tag)
 	if ( ! c )
 		{
 		reporter->Error("unknown writer type requested");
-		return 0;
+		return nullptr;
 		}
 
 	WriterBackend* backend = (*c->Factory())(frontend);
@@ -161,7 +161,7 @@ Manager::Stream* Manager::FindStream(EnumVal* id)
 	unsigned int idx = id->AsEnum();
 
 	if ( idx >= streams.size() || ! streams[idx] )
-		return 0;
+		return nullptr;
 
 	return streams[idx];
 	}
@@ -182,7 +182,7 @@ Manager::WriterInfo* Manager::FindWriter(WriterFrontend* writer)
 			}
 		}
 
-	return 0;
+	return nullptr;
 	}
 
 bool Manager::CompareFields(const Filter* filter, const WriterFrontend* writer)
@@ -264,7 +264,7 @@ bool Manager::CreateStream(EnumVal* id, RecordVal* sval)
 		}
 
 	auto event_val = sval->Lookup("ev");
-	Func* event = event_val ? event_val->AsFunc() : 0;
+	Func* event = event_val ? event_val->AsFunc() : nullptr;
 
 	if ( event )
 		{
@@ -298,7 +298,7 @@ bool Manager::CreateStream(EnumVal* id, RecordVal* sval)
 	unsigned int idx = id->AsEnum();
 
 	while ( idx >= streams.size() )
-		streams.push_back(0);
+		streams.push_back(nullptr);
 
 	if ( streams[idx] )
 		// We already know this one, delete the previous definition.
@@ -309,7 +309,7 @@ bool Manager::CreateStream(EnumVal* id, RecordVal* sval)
 	streams[idx]->id = id->Ref()->AsEnumVal();
 	streams[idx]->enabled = true;
 	streams[idx]->name = id->Type()->AsEnumType()->Lookup(idx);
-	streams[idx]->event = event ? event_registry->Lookup(event->Name()) : 0;
+	streams[idx]->event = event ? event_registry->Lookup(event->Name()) : nullptr;
 	streams[idx]->columns = columns->Ref()->AsRecordType();
 
 	streams[idx]->enable_remote = internal_val("Log::enable_remote_logging")->AsBool();
@@ -347,7 +347,7 @@ bool Manager::RemoveStream(EnumVal* id)
 	stream->writers.clear();
 	string sname(stream->name);
 	delete stream;
-	streams[idx] = 0;
+	streams[idx] = nullptr;
 
 	DBG_LOG(DBG_LOGGING, "Removed logging stream '%s'", sname.c_str());
 	return true;
@@ -523,7 +523,7 @@ bool Manager::TraverseRecord(Stream* stream, Filter* filter, RecordType* rt,
 
 		bool optional = rtype->FieldDecl(i)->FindAttr(ATTR_OPTIONAL);
 
-		filter->fields[filter->num_fields - 1] = new threading::Field(new_path.c_str(), 0, t->Tag(), st, optional);
+		filter->fields[filter->num_fields - 1] = new threading::Field(new_path.c_str(), nullptr, t->Tag(), st, optional);
 		}
 
 	return true;
@@ -565,18 +565,18 @@ bool Manager::AddFilter(EnumVal* id, RecordVal* fval)
 	filter->fval = fval->Ref();
 	filter->name = name->AsString()->CheckString();
 	filter->id = id->Ref()->AsEnumVal();
-	filter->pred = pred ? pred->AsFunc() : 0;
-	filter->path_func = path_func ? path_func->AsFunc() : 0;
+	filter->pred = pred ? pred->AsFunc() : nullptr;
+	filter->path_func = path_func ? path_func->AsFunc() : nullptr;
 	filter->writer = writer->Ref()->AsEnumVal();
 	filter->local = log_local->AsBool();
 	filter->remote = log_remote->AsBool();
 	filter->interval = interv->AsInterval();
-	filter->postprocessor = postprocessor ? postprocessor->AsFunc() : 0;
+	filter->postprocessor = postprocessor ? postprocessor->AsFunc() : nullptr;
 	filter->config = config->Ref()->AsTableVal();
 	filter->field_name_map = field_name_map->Ref()->AsTableVal();
 	filter->scope_sep = scope_sep->AsString()->CheckString();
 	filter->ext_prefix = ext_prefix->AsString()->CheckString();
-	filter->ext_func = ext_func ? ext_func->AsFunc() : 0;
+	filter->ext_func = ext_func ? ext_func->AsFunc() : nullptr;
 
 	// Build the list of fields that the filter wants included, including
 	// potentially rolling out fields.
@@ -604,7 +604,7 @@ bool Manager::AddFilter(EnumVal* id, RecordVal* fval)
 		}
 
 	filter->num_fields = 0;
-	filter->fields = 0;
+	filter->fields = nullptr;
 	if ( ! TraverseRecord(stream, filter, stream->columns,
 			      include ? include->AsTableVal() : nullptr,
 			      exclude ? exclude->AsTableVal() : nullptr,
@@ -627,7 +627,7 @@ bool Manager::AddFilter(EnumVal* id, RecordVal* fval)
 		{
 		// If no path is given, it's derived based upon the value returned by
 		// the first call to the filter's path_func (during first write).
-		filter->path_val = 0;
+		filter->path_val = nullptr;
 		}
 
 	// Remove any filter with the same name we might already have.
@@ -811,8 +811,8 @@ bool Manager::Write(EnumVal* id, RecordVal* columns_arg)
 			path = filter->path = filter->path_val->AsString()->CheckString();
 			}
 
-		WriterBackend::WriterInfo* info = 0;
-		WriterFrontend* writer = 0;
+		WriterBackend::WriterInfo* info = nullptr;
+		WriterFrontend* writer = nullptr;
 
 		if ( w != stream->writers.end() )
 			{
@@ -1125,7 +1125,7 @@ WriterFrontend* Manager::CreateWriter(EnumVal* id, EnumVal* writer, WriterBacken
 				int num_fields, const threading::Field* const* fields, bool local, bool remote, bool from_remote,
 				const string& instantiating_filter)
 	{
-	WriterFrontend* result = 0;
+	WriterFrontend* result = nullptr;
 
 	Stream* stream = FindStream(id);
 
@@ -1133,7 +1133,7 @@ WriterFrontend* Manager::CreateWriter(EnumVal* id, EnumVal* writer, WriterBacken
 		{
 		// Don't know this stream.
 		delete_info_and_fields(info, num_fields, fields);
-		return 0;
+		return nullptr;
 		}
 
 	Stream::WriterMap::iterator w =
@@ -1149,11 +1149,11 @@ WriterFrontend* Manager::CreateWriter(EnumVal* id, EnumVal* writer, WriterBacken
 
 	WriterInfo* winfo = new WriterInfo;
 	winfo->type = writer->Ref()->AsEnumVal();
-	winfo->writer = 0;
+	winfo->writer = nullptr;
 	winfo->open_time = network_time;
-	winfo->rotation_timer = 0;
+	winfo->rotation_timer = nullptr;
 	winfo->interval = 0;
-	winfo->postprocessor = 0;
+	winfo->postprocessor = nullptr;
 	winfo->info = info;
 	winfo->from_remote = from_remote;
 	winfo->hook_initialized = false;
@@ -1194,7 +1194,7 @@ WriterFrontend* Manager::CreateWriter(EnumVal* id, EnumVal* writer, WriterBacken
 	// Still need to set the WriterInfo's rotation parameters, which we
 	// computed above.
 	const char* base_time = log_rotate_base_time ?
-		log_rotate_base_time->AsString()->CheckString() : 0;
+		log_rotate_base_time->AsString()->CheckString() : nullptr;
 
 	winfo->info->rotation_interval = winfo->interval;
 	winfo->info->rotation_base = parse_rotate_base_time(base_time);
@@ -1411,12 +1411,12 @@ protected:
 RotationTimer::~RotationTimer()
 	{
 	if ( winfo->rotation_timer == this )
-		winfo->rotation_timer = 0;
+		winfo->rotation_timer = nullptr;
 	}
 
 void RotationTimer::Dispatch(double t, bool is_expire)
 	{
-	winfo->rotation_timer = 0;
+	winfo->rotation_timer = nullptr;
 
 	if ( rotate )
 		log_mgr->Rotate(winfo);
@@ -1436,7 +1436,7 @@ void Manager::InstallRotationTimer(WriterInfo* winfo)
 	if ( winfo->rotation_timer )
 		{
 		timer_mgr->Cancel(winfo->rotation_timer);
-		winfo->rotation_timer = 0;
+		winfo->rotation_timer = nullptr;
 		}
 
 	double rotation_interval = winfo->interval;
@@ -1454,7 +1454,7 @@ void Manager::InstallRotationTimer(WriterInfo* winfo)
 				winfo->open_time = network_time;
 
 			const char* base_time = log_rotate_base_time ?
-				log_rotate_base_time->AsString()->CheckString() : 0;
+				log_rotate_base_time->AsString()->CheckString() : nullptr;
 
 			double base = parse_rotate_base_time(base_time);
 			double delta_t =
diff --git a/src/logging/Manager.h b/src/logging/Manager.h
index 4d062c6a07..55dc5b68c0 100644
--- a/src/logging/Manager.h
+++ b/src/logging/Manager.h
@@ -261,7 +261,7 @@ private:
 	threading::Value** RecordToFilterVals(Stream* stream, Filter* filter,
 				    RecordVal* columns);
 
-	threading::Value* ValToLogVal(Val* val, BroType* ty = 0);
+	threading::Value* ValToLogVal(Val* val, BroType* ty = nullptr);
 	Stream* FindStream(EnumVal* id);
 	void RemoveDisabledWriters(Stream* stream);
 	void InstallRotationTimer(WriterInfo* winfo);
diff --git a/src/logging/WriterBackend.cc b/src/logging/WriterBackend.cc
index 4512234734..b3bbe8b13e 100644
--- a/src/logging/WriterBackend.cc
+++ b/src/logging/WriterBackend.cc
@@ -121,7 +121,7 @@ bool WriterBackend::WriterInfo::FromBroker(broker::data d)
 WriterBackend::WriterBackend(WriterFrontend* arg_frontend) : MsgThread()
 	{
 	num_fields = 0;
-	fields = 0;
+	fields = nullptr;
 	buffering = true;
 	frontend = arg_frontend;
 	info = new WriterInfo(frontend->Info());
@@ -168,7 +168,7 @@ bool WriterBackend::FinishedRotation(const char* new_name, const char* old_name,
 bool WriterBackend::FinishedRotation()
 	{
 	--rotation_counter;
-	SendOut(new RotationFinishedMessage(frontend, 0, 0, 0, 0, false, false));
+	SendOut(new RotationFinishedMessage(frontend, nullptr, nullptr, 0, 0, false, false));
 	return true;
 	}
 
diff --git a/src/logging/WriterBackend.h b/src/logging/WriterBackend.h
index bb0941322d..805b4f8b9a 100644
--- a/src/logging/WriterBackend.h
+++ b/src/logging/WriterBackend.h
@@ -82,14 +82,14 @@ public:
 		 */
 		config_map config;
 
-		WriterInfo() : path(0), rotation_interval(0.0), rotation_base(0.0),
+		WriterInfo() : path(nullptr), rotation_interval(0.0), rotation_base(0.0),
 		               network_time(0.0)
 			{
 			}
 
 		WriterInfo(const WriterInfo& other)
 			{
-			path = other.path ? copy_string(other.path) : 0;
+			path = other.path ? copy_string(other.path) : nullptr;
 			rotation_interval = other.rotation_interval;
 			rotation_base = other.rotation_base;
 			network_time = other.network_time;
diff --git a/src/logging/WriterFrontend.cc b/src/logging/WriterFrontend.cc
index f8ce418482..c8953b817e 100644
--- a/src/logging/WriterFrontend.cc
+++ b/src/logging/WriterFrontend.cc
@@ -109,12 +109,12 @@ WriterFrontend::WriterFrontend(const WriterBackend::WriterInfo& arg_info, EnumVa
 	buf = true;
 	local = arg_local;
 	remote = arg_remote;
-	write_buffer = 0;
+	write_buffer = nullptr;
 	write_buffer_pos = 0;
 	info = new WriterBackend::WriterInfo(arg_info);
 
 	num_fields = 0;
-	fields = 0;
+	fields = nullptr;
 
 	const char* w = arg_writer->Type()->AsEnumType()->Lookup(arg_writer->InternalInt());
 	name = copy_string(fmt("%s/%s", arg_info.path, w));
@@ -128,7 +128,7 @@ WriterFrontend::WriterFrontend(const WriterBackend::WriterInfo& arg_info, EnumVa
 		}
 
 	else
-		backend = 0;
+		backend = nullptr;
 	}
 
 WriterFrontend::~WriterFrontend()
@@ -152,7 +152,7 @@ void WriterFrontend::Stop()
 	if ( backend )
 		{
 		backend->SignalStop();
-		backend = 0; // Thread manager will clean it up once it finishes.
+		backend = nullptr; // Thread manager will clean it up once it finishes.
 		}
 	}
 
@@ -245,7 +245,7 @@ void WriterFrontend::FlushWriteBuffer()
 		backend->SendIn(new WriteMessage(backend, num_fields, write_buffer_pos, write_buffer));
 
 	// Clear buffer (no delete, we pass ownership to child thread.)
-	write_buffer = 0;
+	write_buffer = nullptr;
 	write_buffer_pos = 0;
 	}
 
@@ -286,7 +286,7 @@ void WriterFrontend::Rotate(const char* rotated_path, double open, double close,
 		backend->SendIn(new RotateMessage(backend, this, rotated_path, open, close, terminating));
 	else
 		// Still signal log manager that we're done.
-		log_mgr->FinishedRotation(this, 0, 0, 0, 0, false, terminating);
+		log_mgr->FinishedRotation(this, nullptr, nullptr, 0, 0, false, terminating);
 	}
 
 void WriterFrontend::DeleteVals(int num_fields, Value** vals)
diff --git a/src/logging/writers/ascii/Ascii.cc b/src/logging/writers/ascii/Ascii.cc
index f598cdc216..71c47042ba 100644
--- a/src/logging/writers/ascii/Ascii.cc
+++ b/src/logging/writers/ascii/Ascii.cc
@@ -24,7 +24,7 @@ Ascii::Ascii(WriterFrontend* frontend) : WriterBackend(frontend)
 	tsv = false;
 	use_json = false;
 	enable_utf_8 = false;
-	formatter = 0;
+	formatter = nullptr;
 	gzip_level = 0;
 	gzfile = nullptr;
 
@@ -179,7 +179,7 @@ bool Ascii::InitFilterOptions()
 bool Ascii::InitFormatter()
 	{
 	delete formatter;
-	formatter = 0;
+	formatter = nullptr;
 
 	if ( use_json )
 		{
diff --git a/src/threading/BasicThread.cc b/src/threading/BasicThread.cc
index 3374380748..c447051bab 100644
--- a/src/threading/BasicThread.cc
+++ b/src/threading/BasicThread.cc
@@ -22,7 +22,7 @@ BasicThread::BasicThread()
 	buf_len = STD_FMT_BUF_LEN;
 	buf = (char*) safe_malloc(buf_len);
 
-	strerr_buffer = 0;
+	strerr_buffer = nullptr;
 
 	name = copy_string(fmt("thread-%" PRIu64, ++thread_counter));
 
@@ -191,5 +191,5 @@ void* BasicThread::launcher(void *arg)
 
 	thread->Done();
 
-	return 0;
+	return nullptr;
 	}
diff --git a/src/threading/MsgThread.cc b/src/threading/MsgThread.cc
index f662d0a46c..2b6ef01ead 100644
--- a/src/threading/MsgThread.cc
+++ b/src/threading/MsgThread.cc
@@ -172,7 +172,7 @@ bool ReporterMessage::Process()
 	return true;
 	}
 
-MsgThread::MsgThread() : BasicThread(), queue_in(this, 0), queue_out(0, this)
+MsgThread::MsgThread() : BasicThread(), queue_in(this, nullptr), queue_out(nullptr, this)
 	{
 	cnt_sent_in = cnt_sent_out = 0;
 	main_finished = false;
@@ -367,7 +367,7 @@ BasicOutputMessage* MsgThread::RetrieveOut()
 	{
 	BasicOutputMessage* msg = queue_out.Get();
 	if ( ! msg )
-		return 0;
+		return nullptr;
 
 	DBG_LOG(DBG_THREADING, "Retrieved '%s' from %s",  msg->Name(), Name());
 
@@ -379,7 +379,7 @@ BasicInputMessage* MsgThread::RetrieveIn()
 	BasicInputMessage* msg = queue_in.Get();
 
 	if ( ! msg )
-		return 0;
+		return nullptr;
 
 #ifdef DEBUG
 	string s = Fmt("Retrieved '%s' in %s",  msg->Name(), Name());
diff --git a/src/threading/SerialTypes.cc b/src/threading/SerialTypes.cc
index bd85b846f9..b04549f0b6 100644
--- a/src/threading/SerialTypes.cc
+++ b/src/threading/SerialTypes.cc
@@ -26,7 +26,7 @@ bool Field::Read(SerializationFormat* fmt)
 		secondary_name = copy_string(tmp_secondary_name.c_str());
 		}
 	else
-		secondary_name = 0;
+		secondary_name = nullptr;
 
 	bool success = (fmt->Read(&tmp_name, "name")
 			&& fmt->Read(&t, "type")
diff --git a/src/threading/SerialTypes.h b/src/threading/SerialTypes.h
index dbd3635b94..628c3b40f7 100644
--- a/src/threading/SerialTypes.h
+++ b/src/threading/SerialTypes.h
@@ -31,16 +31,16 @@ struct Field {
 	 * Constructor.
 	 */
 	Field(const char* name, const char* secondary_name, TypeTag type, TypeTag subtype, bool optional)
-		: name(name ? copy_string(name) : 0),
-		  secondary_name(secondary_name ? copy_string(secondary_name) : 0),
+		: name(name ? copy_string(name) : nullptr),
+		  secondary_name(secondary_name ? copy_string(secondary_name) : nullptr),
 		  type(type), subtype(subtype), optional(optional)	{ }
 
 	/**
 	 * Copy constructor.
 	 */
 	Field(const Field& other)
-		: name(other.name ? copy_string(other.name) : 0),
-		  secondary_name(other.secondary_name ? copy_string(other.secondary_name) : 0),
+		: name(other.name ? copy_string(other.name) : nullptr),
+		  secondary_name(other.secondary_name ? copy_string(other.secondary_name) : nullptr),
 		  type(other.type), subtype(other.subtype), optional(other.optional)	{ }
 
 	~Field()
diff --git a/src/threading/formatters/Ascii.cc b/src/threading/formatters/Ascii.cc
index ce8d5461f6..a5337dac1e 100644
--- a/src/threading/formatters/Ascii.cc
+++ b/src/threading/formatters/Ascii.cc
@@ -214,7 +214,7 @@ threading::Value* Ascii::ParseValue(const string& s, const string& name, TypeTag
 
 	threading::Value* val = new threading::Value(type, subtype, true);
 	const char* start = s.c_str();
-	char* end = 0;
+	char* end = nullptr;
 	errno = 0;
 	size_t pos;
 
@@ -411,7 +411,7 @@ threading::Value* Ascii::ParseValue(const string& s, const string& name, TypeTag
 				}
 
 			threading::Value* newval = ParseValue(element, name, subtype);
-			if ( newval == 0 )
+			if ( newval == nullptr )
 				{
 				GetThread()->Warning("Error while reading set or vector");
 				error = true;
@@ -429,7 +429,7 @@ threading::Value* Ascii::ParseValue(const string& s, const string& name, TypeTag
 		if ( ! error && (s.empty() || *s.rbegin() == separators.set_separator[0]) )
 			{
 			lvals[pos] = ParseValue("", name, subtype);
-			if ( lvals[pos] == 0 )
+			if ( lvals[pos] == nullptr )
 				{
 				GetThread()->Warning("Error while trying to add empty set element");
 				goto parse_error;
@@ -470,7 +470,7 @@ threading::Value* Ascii::ParseValue(const string& s, const string& name, TypeTag
 
 parse_error:
 	delete val;
-	return 0;
+	return nullptr;
 	}
 
 bool Ascii::CheckNumberError(const char* start, const char* end) const