NULL -> nullptr

47 files changed, 356 insertions, 356 deletions

diff --git a/fastos/src/tests/backtracetest.cpp b/fastos/src/tests/backtracetest.cpp
index df0887c6b63..6c68765c1ee 100644
--- a/fastos/src/tests/backtracetest.cpp
+++ b/fastos/src/tests/backtracetest.cpp
@@ -116,7 +116,7 @@ int main (int argc, char **argv)
 {
     BackTraceTest app;
 
-    setvbuf(stdout, NULL, _IOLBF, 8192);
+    setvbuf(stdout, nullptr, _IOLBF, 8192);
     return app.Entry(argc, argv);
 }
 
diff --git a/fastos/src/tests/coretest.cpp b/fastos/src/tests/coretest.cpp
index 2337c392730..a53eaf9d2a4 100644
--- a/fastos/src/tests/coretest.cpp
+++ b/fastos/src/tests/coretest.cpp
@@ -8,7 +8,7 @@ bomb(void)
 {
     char *p;
 
-    p = NULL;
+    p = nullptr;
     *p = 4;
 }
 
@@ -29,8 +29,8 @@ bombMain(void)
     FastS_Bomber bomber;
     FastOS_ThreadInterface *thread;
 
-    thread =  pool->NewThread(&bomber, NULL);
-    if (thread != NULL)
+    thread =  pool->NewThread(&bomber, nullptr);
+    if (thread != nullptr)
         thread->Join();
 
     pool->Close();
@@ -60,7 +60,7 @@ int
 main(int argc, char **argv)
 {
   FastS_CoreTestApp app;
-  setvbuf(stdout, NULL, _IOLBF, 8192);
+  setvbuf(stdout, nullptr, _IOLBF, 8192);
   if (argc == 1)
       return app.Entry(argc, argv);
   else
diff --git a/fastos/src/tests/coretest2.cpp b/fastos/src/tests/coretest2.cpp
index a8c416f2de4..e11d334e65e 100644
--- a/fastos/src/tests/coretest2.cpp
+++ b/fastos/src/tests/coretest2.cpp
@@ -8,7 +8,7 @@ bomb(void)
 {
     char *p;
 
-    p = NULL;
+    p = nullptr;
     *p = 4;
 }
 
@@ -16,7 +16,7 @@ void *BomberRun(void *arg)
 {
     (void) arg;
     bomb();
-    return NULL;
+    return nullptr;
 };
 
 static int
@@ -25,8 +25,8 @@ bombMain(void)
     pthread_t thread;
     void *ret;
 
-    (void) pthread_create(&thread, NULL, BomberRun, NULL);
-    ret = NULL;
+    (void) pthread_create(&thread, nullptr, BomberRun, nullptr);
+    ret = nullptr;
     (void) pthread_join(thread, &ret);
     return (0);
 }
diff --git a/fastos/src/tests/filetest.cpp b/fastos/src/tests/filetest.cpp
index ad411364c0c..e063ccbc89d 100644
--- a/fastos/src/tests/filetest.cpp
+++ b/fastos/src/tests/filetest.cpp
@@ -278,7 +278,7 @@ public:
             Progress(rc, "Opening file 'generated/memorymaptest' read-only");
             if (rc) {
                 bool mmapEnabled;
-                char *mmapBuffer = NULL;
+                char *mmapBuffer = nullptr;
 
                 mmapEnabled = file.IsMemoryMapped();
                 mmapBuffer = static_cast<char *>(file.MemoryMapPtr(0));
@@ -832,6 +832,6 @@ int main (int argc, char **argv)
 {
     FileTest app;
 
-    setvbuf(stdout, NULL, _IOLBF, 8192);
+    setvbuf(stdout, nullptr, _IOLBF, 8192);
     return app.Entry(argc, argv);
 }
diff --git a/fastos/src/tests/job.h b/fastos/src/tests/job.h
index 5199169409d..a5b84fa0f9c 100644
--- a/fastos/src/tests/job.h
+++ b/fastos/src/tests/job.h
@@ -42,17 +42,17 @@ public:
 
    Job()
      : code(NOP),
-       message(NULL),
-       mutex(NULL),
-       condition(NULL),
-       boolcondition(NULL),
-       otherThread(NULL),
-       ownThread(NULL),
-       timebuf(NULL),
+       message(nullptr),
+       mutex(nullptr),
+       condition(nullptr),
+       boolcondition(nullptr),
+       otherThread(nullptr),
+       ownThread(nullptr),
+       timebuf(nullptr),
        average(0.0),
        result(-1),
        _threadId(),
-       otherjob(NULL),
+       otherjob(nullptr),
        bouncewakeupcnt(0),
        bouncewakeup(false)
    {
@@ -60,7 +60,7 @@ public:
 
    ~Job()
    {
-      if(message != NULL)
+      if(message != nullptr)
          free(message);
    }
 };
diff --git a/fastos/src/tests/performancetest.cpp b/fastos/src/tests/performancetest.cpp
index 1465ee3d223..55174fcc4e3 100644
--- a/fastos/src/tests/performancetest.cpp
+++ b/fastos/src/tests/performancetest.cpp
@@ -12,14 +12,14 @@ int main (int argc, char **argv)
 
    void (*test)(char *buffer) = PerformanceTest;
 
-   test(NULL);
+   test(nullptr);
    return 0;
 }
 
 void PerformanceTest (char *buffer)
 {
    // Cause exception
-   *static_cast<char *>(NULL) = 'e';
+   *static_cast<char *>(nullptr) = 'e';
 
 #if 1
    FastOS_File file("test.txt");
diff --git a/fastos/src/tests/prefetchtest.cpp b/fastos/src/tests/prefetchtest.cpp
index 26ab67251b3..38d3eed837c 100644
--- a/fastos/src/tests/prefetchtest.cpp
+++ b/fastos/src/tests/prefetchtest.cpp
@@ -35,7 +35,7 @@ public:
       size = 32;
       size *= 1024*1024/sizeof(*a);
 
-      if ((a = static_cast<int *>(calloc(size, sizeof(*a)))) != NULL)
+      if ((a = static_cast<int *>(calloc(size, sizeof(*a)))) != nullptr)
       {
          // Standard loop
          start.SetNow();
@@ -155,6 +155,6 @@ public:
 int main (int argc, char **argv)
 {
    PrefetchTestApp app;
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    return app.Entry(argc, argv);
 }
diff --git a/fastos/src/tests/processtest.cpp b/fastos/src/tests/processtest.cpp
index 5036676a504..11e1307027d 100644
--- a/fastos/src/tests/processtest.cpp
+++ b/fastos/src/tests/processtest.cpp
@@ -47,7 +47,7 @@ public:
    void OnReceiveData (const void *data, size_t length) override
    {
       _receivedBytes += length;
-      if(data != NULL)
+      if(data != nullptr)
       {
 #if 0
          printf("[%s] received %u bytes of data:\n%s\n",
@@ -62,7 +62,7 @@ public:
 int MyListener::_allocCount = 0;
 int MyListener::_successCount = 0;
 int MyListener::_failCount = 0;
-FastOS_Mutex *MyListener::_counterLock = NULL;
+FastOS_Mutex *MyListener::_counterLock = nullptr;
 
 
 class ThreadRunJob : public FastOS_Runnable
@@ -128,7 +128,7 @@ public:
    ProcessTest ()
      : _gotMessage(false),
        _receivedMessages(0),
-       _counterLock(NULL),
+       _counterLock(nullptr),
        _isChild(true)
    {
    }
@@ -154,7 +154,7 @@ public:
       _gotMessage = true;
 
       // We only have the counter lock if we are the parent process.
-      if(_counterLock != NULL)
+      if(_counterLock != nullptr)
       {
          _counterLock->Lock();
          _receivedMessages++;
@@ -197,7 +197,7 @@ public:
             if(i == 5)
             {
                // Make sort quit
-               xproc->WriteStdin(NULL, 0);
+               xproc->WriteStdin(nullptr, 0);
             }
 
             FastOS_Thread::Sleep(1000);
@@ -257,7 +257,7 @@ public:
                if(!waitKill && stdinPre)
                {
                   xproc->WriteStdin(str, strlen(str));
-                  xproc->WriteStdin(NULL, 0);
+                  xproc->WriteStdin(nullptr, 0);
                }
 
                if(doKill)
@@ -269,7 +269,7 @@ public:
                if(!waitKill && !stdinPre)
                {
                   xproc->WriteStdin(str, strlen(str));
-                  xproc->WriteStdin(NULL, 0);
+                  xproc->WriteStdin(nullptr, 0);
                }
             }
             else
@@ -277,7 +277,7 @@ public:
                Progress(false, "Process.CreateWithShell failure %d",
                         GetLastError());
                delete xproc;
-               xproc = NULL;
+               xproc = nullptr;
             }
             procs[j] = xproc;
          }
@@ -285,7 +285,7 @@ public:
          for(j=0; j<numEachTime; j++)
          {
             FastOS_ProcessInterface *xproc = procs[j];
-            if(xproc == NULL)
+            if(xproc == nullptr)
                continue;
 
             int timeOut = -1;
@@ -347,7 +347,7 @@ public:
       }
 
       delete MyListener::_counterLock;
-      MyListener::_counterLock = NULL;
+      MyListener::_counterLock = nullptr;
 
       PrintSeparator();
    }
@@ -412,7 +412,7 @@ public:
                "Received %d messages", _receivedMessages);
 
       delete _counterLock;
-      _counterLock = NULL;
+      _counterLock = nullptr;
 
       PrintSeparator();
    }
@@ -427,8 +427,8 @@ public:
       void *inheritData = FastOS_Process::PrefopenNoInherit();
       FILE *fp = fopen(filename, "w");
       int numProc = FastOS_Process::PostfopenNoInherit(inheritData);
-      Progress(fp != NULL, "Open file");
-      if(fp != NULL)
+      Progress(fp != nullptr, "Open file");
+      if(fp != nullptr)
       {
          Progress(numProc > 0, "Number of files processed = %d\n",
                   numProc);
@@ -469,6 +469,6 @@ public:
 int main (int argc, char **argv)
 {
    ProcessTest app;
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    return app.Entry(argc, argv);
 }
diff --git a/fastos/src/tests/sockettest.cpp b/fastos/src/tests/sockettest.cpp
index 3a9c9dab565..29dcb1b089e 100644
--- a/fastos/src/tests/sockettest.cpp
+++ b/fastos/src/tests/sockettest.cpp
@@ -150,7 +150,7 @@ public:
    BaseTest *_app;
 
    MazeServer(BaseTest *app)
-     : _serverSocket(NULL),
+     : _serverSocket(nullptr),
        _app(app)
    {
    }
@@ -185,7 +185,7 @@ public:
             {
                int serverPort = 18334;
                _serverSocket = new FastOS_ServerSocket(serverPort);
-               _app->Progress(_serverSocket != NULL,
+               _app->Progress(_serverSocket != nullptr,
                               "Creating ServerSocket instance");
 
                _app->Progress(_serverSocket->SetSoBlocking(false),
@@ -224,12 +224,12 @@ public:
                {
                   FastOS_Socket *connSocket = _serverSocket->AcceptPlain();
 
-                  _app->Progress(connSocket != NULL, "Accepting socket (%p)",
+                  _app->Progress(connSocket != nullptr, "Accepting socket (%p)",
                                  connSocket);
 
                   for(i=0; i<MAX_CONNECTIONS; i++)
                   {
-                     if(connections[i] == NULL)
+                     if(connections[i] == nullptr)
                      {
                         // Found a free positions for the new connection
                         break;
@@ -237,11 +237,11 @@ public:
                   }
                   if(i < MAX_CONNECTIONS)
                   {
-                     if(connSocket != NULL)
+                     if(connSocket != nullptr)
                      {
                         connections[i] = new MazeServerConnection(this, connSocket);
 
-                        assert(connections[i] != NULL);
+                        assert(connections[i] != nullptr);
 
                         connSocket->SetSocketEvent(&socketEvent);
                         connSocket->EnableReadEvent(true);
@@ -256,7 +256,7 @@ public:
 
                for(i=0; i<MAX_CONNECTIONS; i++)
                {
-                  if((conn = connections[i]) != NULL)
+                  if((conn = connections[i]) != nullptr)
                   {
                      if(socketEvent.QueryReadEvent(conn->_socket))
                      {
@@ -273,7 +273,7 @@ public:
                      if(conn->_shouldFree)
                      {
                         delete(conn);
-                        connections[i] = NULL;
+                        connections[i] = nullptr;
                      }
                   }
                }
@@ -438,7 +438,7 @@ public:
 #if 0
    void PrintOut()
    {
-      if(_server != NULL)
+      if(_server != nullptr)
       {
          for(int y=0; y<MAZE_HEIGHT; y++)
          {
@@ -460,7 +460,7 @@ public:
 #if 0
    void MarkPath (int x, int y, int direction, int length)
    {
-      if(_server != NULL)
+      if(_server != nullptr)
       {
          int dx, dy;
          SetDirection(dx, dy, direction);
@@ -657,9 +657,9 @@ public:
       std::string strictBindHost("localhost");
 
       FastOS_ServerSocket *serverSocket =
-         new FastOS_ServerSocket(18333, 5, NULL, strictBindHost.c_str());
+         new FastOS_ServerSocket(18333, 5, nullptr, strictBindHost.c_str());
 
-      Progress(serverSocket != NULL, "Allocating serversocket instance");
+      Progress(serverSocket != nullptr, "Allocating serversocket instance");
 
       rc = serverSocket->GetValidAddressFlag();
       Progress(rc, "Address Valid Flag check");
@@ -684,7 +684,7 @@ public:
       TestHeader("HTTP Client Test");
 
       FastOS_Socket *sock = new FastOS_Socket();
-      Progress(sock != NULL, "Allocating socket instance");
+      Progress(sock != nullptr, "Allocating socket instance");
 
       char hostAddress[] = "www.vg.no";
 
@@ -714,7 +714,7 @@ public:
             int readLength = strlen(expectedResult);
             char *readBuffer = new char[readLength+1];
 
-            if(readBuffer != NULL)
+            if(readBuffer != nullptr)
             {
                memset(readBuffer, 0, readLength+1);
 
@@ -756,7 +756,7 @@ public:
       TestHeader("Client/Server Test");
 
       FastOS_ServerSocket *serverSocket = new FastOS_ServerSocket(18333);
-      Progress(serverSocket != NULL, "Allocating serversocket instance");
+      Progress(serverSocket != nullptr, "Allocating serversocket instance");
 
       Progress(rc = serverSocket->Listen(), "Bind socket to port %d. Listen for incoming connections.", 18333);
       assert(rc);
@@ -775,7 +775,7 @@ public:
       bool rc;
       FastOS_Socket *sock = new FastOS_Socket();
 
-      Progress(rc = (sock != NULL), "Allocating socket instance");
+      Progress(rc = (sock != nullptr), "Allocating socket instance");
       if(rc)
       {
          sock->SetAddress(8001, serverAddress);
@@ -786,7 +786,7 @@ public:
          {
             MazeClient *client = new MazeClient(this, sock);
 
-            Progress(rc = (client != NULL), "Allocating MazeClient instance");
+            Progress(rc = (client != nullptr), "Allocating MazeClient instance");
             if(rc)
             {
                client->Run();
@@ -818,7 +818,7 @@ public:
 #if DO_MAZE_SERVER
       DoMazeServer();
 #else
-      char *mazeServerAddress = NULL;
+      char *mazeServerAddress = nullptr;
 
       if(_argc == 3)
       {
@@ -832,7 +832,7 @@ public:
       ClientServerTest();
       StrictBindTest();
 
-      if(mazeServerAddress != NULL)
+      if(mazeServerAddress != nullptr)
          MazeTest(mazeServerAddress);
 #endif
 
@@ -850,6 +850,6 @@ int main (int argc, char **argv)
 {
    SocketTest app;
 
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    return app.Entry(argc, argv);
 }
diff --git a/fastos/src/tests/thread_bounce_test.cpp b/fastos/src/tests/thread_bounce_test.cpp
index 729c16fab5f..bf94f3e1aab 100644
--- a/fastos/src/tests/thread_bounce_test.cpp
+++ b/fastos/src/tests/thread_bounce_test.cpp
@@ -89,6 +89,6 @@ int Thread_Bounce_Test::Main ()
 int main (int argc, char **argv)
 {
    Thread_Bounce_Test app;
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    return app.Entry(argc, argv);
 }
diff --git a/fastos/src/tests/thread_joinwait_test.cpp b/fastos/src/tests/thread_joinwait_test.cpp
index 98e0a1ac467..05ab1627334 100644
--- a/fastos/src/tests/thread_joinwait_test.cpp
+++ b/fastos/src/tests/thread_joinwait_test.cpp
@@ -38,7 +38,7 @@ class Thread_JoinWait_Test : public ThreadTestBase
          jobs[i].ownThread = pool.NewThread(this,
                  static_cast<void *>(&jobs[i]));
 
-         rc = (jobs[i].ownThread != NULL);
+         rc = (jobs[i].ownThread != nullptr);
          Progress(rc, "Creating Thread %d", i+1);
 
          if(!rc)
@@ -56,7 +56,7 @@ class Thread_JoinWait_Test : public ThreadTestBase
                                      static_cast<void *>
                                      (&jobs[lastThreadNum]));
 
-         rc = (lastThread != NULL);
+         rc = (lastThread != nullptr);
          Progress(rc, "Creating last thread");
 
          if(rc)
@@ -115,6 +115,6 @@ int Thread_JoinWait_Test::Main ()
 int main (int argc, char **argv)
 {
    Thread_JoinWait_Test app;
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    return app.Entry(argc, argv);
 }
diff --git a/fastos/src/tests/thread_mutex_test.cpp b/fastos/src/tests/thread_mutex_test.cpp
index 602d89c0b05..b8ac575038b 100644
--- a/fastos/src/tests/thread_mutex_test.cpp
+++ b/fastos/src/tests/thread_mutex_test.cpp
@@ -21,11 +21,11 @@ class Thread_Mutex_Test : public ThreadTestBase
 
       FastOS_ThreadPool *pool = new FastOS_ThreadPool(128*1024, MAX_THREADS);
 
-      if(Progress(pool != NULL, "Allocating ThreadPool"))
+      if(Progress(pool != nullptr, "Allocating ThreadPool"))
       {
          int i;
          Job jobs[MUTEX_TEST_THREADS];
-         FastOS_Mutex *myMutex=NULL;
+         FastOS_Mutex *myMutex=nullptr;
 
          if(usingMutex)
             myMutex = new FastOS_Mutex();
@@ -40,7 +40,7 @@ class Thread_Mutex_Test : public ThreadTestBase
 
          for(i=0; i<MUTEX_TEST_THREADS; i++)
          {
-            bool rc = (NULL != pool->NewThread(this,
+            bool rc = (nullptr != pool->NewThread(this,
                                static_cast<void *>(&jobs[i])));
             Progress(rc, "Creating Thread with%s mutex", (usingMutex ? "" : "out"));
          };
@@ -99,7 +99,7 @@ class Thread_Mutex_Test : public ThreadTestBase
             }
          }
 
-         if(myMutex != NULL)
+         if(myMutex != nullptr)
             delete(myMutex);
 
          Progress(true, "Closing threadpool...");
@@ -125,9 +125,9 @@ class Thread_Mutex_Test : public ThreadTestBase
       job.ownThread = pool.NewThread(this,
                                      static_cast<void *>(&job));
 
-      Progress(job.ownThread !=NULL, "Creating thread");
+      Progress(job.ownThread !=nullptr, "Creating thread");
 
-      if(job.ownThread != NULL)
+      if(job.ownThread != nullptr)
       {
          bool lockrc;
 
@@ -188,6 +188,6 @@ int Thread_Mutex_Test::Main ()
 int main (int argc, char **argv)
 {
    Thread_Mutex_Test app;
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    return app.Entry(argc, argv);
 }
diff --git a/fastos/src/tests/thread_sleep_test.cpp b/fastos/src/tests/thread_sleep_test.cpp
index 914438cdd83..7fd3412b7c3 100644
--- a/fastos/src/tests/thread_sleep_test.cpp
+++ b/fastos/src/tests/thread_sleep_test.cpp
@@ -14,9 +14,9 @@ class Thread_Sleep_Test : public ThreadTestBase
 
       FastOS_ThreadPool *pool = new FastOS_ThreadPool(128*1024);
 
-      if(Progress(pool != NULL, "Allocating ThreadPool"))
+      if(Progress(pool != nullptr, "Allocating ThreadPool"))
       {
-         bool rc = (NULL != pool->NewThread(this, NULL));
+         bool rc = (nullptr != pool->NewThread(this, nullptr));
          Progress(rc, "Creating Thread");
 
          Progress(true, "Sleeping 3 seconds");
@@ -47,6 +47,6 @@ int Thread_Sleep_Test::Main ()
 int main (int argc, char **argv)
 {
    Thread_Sleep_Test app;
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    return app.Entry(argc, argv);
 }
diff --git a/fastos/src/tests/thread_stats_test.cpp b/fastos/src/tests/thread_stats_test.cpp
index 3ac4b0a52d6..3633c12bcaa 100644
--- a/fastos/src/tests/thread_stats_test.cpp
+++ b/fastos/src/tests/thread_stats_test.cpp
@@ -131,6 +131,6 @@ int Thread_Stats_Test::Main ()
 int main (int argc, char **argv)
 {
    Thread_Stats_Test app;
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    return app.Entry(argc, argv);
 }
diff --git a/fastos/src/tests/thread_test_base.hpp b/fastos/src/tests/thread_test_base.hpp
index 3cd16065726..5305b132d3c 100644
--- a/fastos/src/tests/thread_test_base.hpp
+++ b/fastos/src/tests/thread_test_base.hpp
@@ -57,7 +57,7 @@ public:
 
 void ThreadTestBase::Run (FastOS_ThreadInterface *thread, void *arg)
 {
-   if(arg == NULL)
+   if(arg == nullptr)
       return;
 
    Job *job = static_cast<Job *>(arg);
@@ -93,7 +93,7 @@ void ThreadTestBase::Run (FastOS_ThreadInterface *thread, void *arg)
       {
          int result;
 
-         if(job->mutex != NULL)
+         if(job->mutex != nullptr)
             job->mutex->Lock();
 
          result = static_cast<int>(number);
@@ -107,7 +107,7 @@ void ThreadTestBase::Run (FastOS_ThreadInterface *thread, void *arg)
                FastOS_Thread::Sleep(1000);
          }
 
-         if(job->mutex != NULL)
+         if(job->mutex != nullptr)
             job->mutex->Unlock();
 
          job->result = result;  // This marks the end of the thread
@@ -135,7 +135,7 @@ void ThreadTestBase::Run (FastOS_ThreadInterface *thread, void *arg)
          if(job->mutex)
             job->mutex->Lock();
 
-         if(job->otherThread != NULL)
+         if(job->otherThread != nullptr)
             job->otherThread->Join();
 
          if(job->mutex)
diff --git a/fastos/src/tests/threadtest.cpp b/fastos/src/tests/threadtest.cpp
index 57e60d9413b..81ea234fb97 100644
--- a/fastos/src/tests/threadtest.cpp
+++ b/fastos/src/tests/threadtest.cpp
@@ -54,7 +54,7 @@ class ThreadTest : public ThreadTestBase
 
       FastOS_ThreadPool *pool = new FastOS_ThreadPool(128*1024, MAX_THREADS);
 
-      if(Progress(pool != NULL, "Allocating ThreadPool"))
+      if(Progress(pool != nullptr, "Allocating ThreadPool"))
       {
          int i;
          Job jobs[MAX_THREADS];
@@ -70,13 +70,13 @@ class ThreadTest : public ThreadTestBase
          {
             if(i==MAX_THREADS)
             {
-               bool rc = (NULL == pool->NewThread(this,
+               bool rc = (nullptr == pool->NewThread(this,
                                   static_cast<void *>(&jobs[0])));
                Progress(rc, "Creating too many threads should fail.");
             }
             else
             {
-               bool rc = (NULL != pool->NewThread(this,
+               bool rc = (nullptr != pool->NewThread(this,
                                   static_cast<void *>(&jobs[i])));
                Progress(rc, "Creating Thread");
             }
@@ -110,7 +110,7 @@ class ThreadTest : public ThreadTestBase
 
       FastOS_ThreadPool *pool = new FastOS_ThreadPool(128*1024, HOW_MAX_THREADS);
 
-      if(Progress(pool != NULL, "Allocating ThreadPool"))
+      if(Progress(pool != nullptr, "Allocating ThreadPool"))
       {
          int i;
          Job jobs[HOW_MAX_THREADS];
@@ -126,13 +126,13 @@ class ThreadTest : public ThreadTestBase
          {
             if(i==HOW_MAX_THREADS)
             {
-               bool rc = (NULL == pool->NewThread(this,
+               bool rc = (nullptr == pool->NewThread(this,
                                   static_cast<void *>(&jobs[0])));
                Progress(rc, "Creating too many threads should fail.");
             }
             else
             {
-               bool rc = (NULL != pool->NewThread(this,
+               bool rc = (nullptr != pool->NewThread(this,
                                   static_cast<void *>(&jobs[i])));
                Progress(rc, "Creating Thread");
             }
@@ -164,14 +164,14 @@ class ThreadTest : public ThreadTestBase
 
       FastOS_ThreadPool *pool = new FastOS_ThreadPool(128*1024);
 
-      if(Progress(pool != NULL, "Allocating ThreadPool"))
+      if(Progress(pool != nullptr, "Allocating ThreadPool"))
       {
          Job job;
 
          job.code = NOP;
          job.result = -1;
 
-         bool rc = (NULL != pool->NewThread(this, &job));
+         bool rc = (nullptr != pool->NewThread(this, &job));
          Progress(rc, "Creating Thread");
 
          WaitForThreadsToFinish(&job, 1);
@@ -201,8 +201,8 @@ class ThreadTest : public ThreadTestBase
     FastOS_ThreadPool *pool = new FastOS_ThreadPool(128 * 1024);
 
     if (!silent)
-      Progress(pool != NULL, "Allocating ThreadPool");
-    if (pool != NULL) {
+      Progress(pool != nullptr, "Allocating ThreadPool");
+    if (pool != nullptr) {
       Job *jobs = new Job[count];
 
       threadsok = 0;
@@ -210,23 +210,23 @@ class ThreadTest : public ThreadTestBase
       for (i = 0; i < count; i++) {
         jobs[i].code = SILENTNOP;
         jobs[i].ownThread = pool->NewThread(this, &jobs[i]);
-        rc = (jobs[i].ownThread != NULL);
+        rc = (jobs[i].ownThread != nullptr);
         if (rc)
           threadsok++;
       }
 
       for (j = 0; j < outercount; j++) {
         for (i = 0; i < count; i++) {
-          if (jobs[i].ownThread != NULL)
+          if (jobs[i].ownThread != nullptr)
             jobs[i].ownThread->Join();
           jobs[i].ownThread = pool->NewThread(this, &jobs[i]);
-          rc = (jobs[i].ownThread != NULL);
+          rc = (jobs[i].ownThread != nullptr);
           if (rc)
             threadsok++;
         }
       }
       for (i = 0; i < count; i++) {
-        if (jobs[i].ownThread != NULL)
+        if (jobs[i].ownThread != nullptr)
           jobs[i].ownThread->Join();
       }
       endtime.SetNow();
@@ -286,7 +286,7 @@ class ThreadTest : public ThreadTestBase
       {
          jobs[i].code = INCREASE_NUMBER;
 
-         bool rc = (NULL != pool.NewThread(this,
+         bool rc = (nullptr != pool.NewThread(this,
                             static_cast<void *>(&jobs[i])));
          Progress(rc, "Creating Thread %d", i+1);
       }
@@ -311,7 +311,7 @@ class ThreadTest : public ThreadTestBase
       {
          jobs[i].code = WAIT_FOR_BREAK_FLAG;
 
-         bool rc = (NULL != pool.NewThread(this,
+         bool rc = (nullptr != pool.NewThread(this,
                             static_cast<void *>(&jobs[i])));
          Progress(rc, "Creating Thread %d", i+1);
       }
@@ -333,7 +333,7 @@ class ThreadTest : public ThreadTestBase
          jobs[i].ownThread = pool->NewThread(this,
                  static_cast<void *>(&jobs[i]));
 
-         bool rc=(jobs[i].ownThread != NULL);
+         bool rc=(jobs[i].ownThread != nullptr);
          Progress(rc, "CreatingThread %d", i+1);
       }
 
@@ -412,7 +412,7 @@ class ThreadTest : public ThreadTestBase
          jobs[i].mutex = &slowStartMutex;
          jobs[i].ownThread = pool.NewThread(this,
                  static_cast<void *>(&jobs[i]));
-         bool rc=(jobs[i].ownThread != NULL);
+         bool rc=(jobs[i].ownThread != nullptr);
          if(rc)
             jobs[i]._threadId = jobs[i].ownThread->GetThreadId();
          Progress(rc, "CreatingThread %d id:%lu", i+1,
@@ -457,9 +457,9 @@ class ThreadTest : public ThreadTestBase
       job.ownThread = pool.NewThread(this,
                                      static_cast<void *>(&job));
 
-      Progress(job.ownThread !=NULL, "Creating thread");
+      Progress(job.ownThread !=nullptr, "Creating thread");
 
-      if(job.ownThread != NULL)
+      if(job.ownThread != nullptr)
       {
          condition.Lock();
          bool gotCond = condition.TimedWait(500);
@@ -597,6 +597,6 @@ int ThreadTest::Main ()
 int main (int argc, char **argv)
 {
    ThreadTest app;
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    return app.Entry(argc, argv);
 }
diff --git a/fastos/src/tests/timetest.cpp b/fastos/src/tests/timetest.cpp
index fa9ef71ba9c..0618e28bcd0 100644
--- a/fastos/src/tests/timetest.cpp
+++ b/fastos/src/tests/timetest.cpp
@@ -290,7 +290,7 @@ int main (int argc, char **argv)
 {
    TimeTest app;
 
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    return app.Entry(argc, argv);
 }
 
diff --git a/fastos/src/tests/typetest.cpp b/fastos/src/tests/typetest.cpp
index 87e3d76c461..51bda7e5dbc 100644
--- a/fastos/src/tests/typetest.cpp
+++ b/fastos/src/tests/typetest.cpp
@@ -51,7 +51,7 @@ public:
 
 int main (int argc, char **argv)
 {
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    TypeTest app;
    return app.Entry(argc, argv);
 }
diff --git a/fastos/src/tests/usecputest.cpp b/fastos/src/tests/usecputest.cpp
index 930b1fb305f..9812ed7575d 100644
--- a/fastos/src/tests/usecputest.cpp
+++ b/fastos/src/tests/usecputest.cpp
@@ -63,7 +63,7 @@ void UseSomeCpu (int i, ThreadRunJob *threadRunJob)
 int main (int argc, char **argv)
 {
    UseCpuTest app;
-   setvbuf(stdout, NULL, _IOLBF, 8192);
+   setvbuf(stdout, nullptr, _IOLBF, 8192);
    return app.Entry(argc, argv);
 }
 
diff --git a/fastos/src/vespa/fastos/app.cpp b/fastos/src/vespa/fastos/app.cpp
index 079dab55754..824d009591f 100644
--- a/fastos/src/vespa/fastos/app.cpp
+++ b/fastos/src/vespa/fastos/app.cpp
@@ -27,16 +27,16 @@ FastOS_ThreadPool *FastOS_ApplicationInterface::GetThreadPool ()
 }
 
 FastOS_ApplicationInterface::FastOS_ApplicationInterface() :
-    _threadPool(NULL),
-    _processList(NULL),
-    _processListMutex(NULL),
+    _threadPool(nullptr),
+    _processList(nullptr),
+    _processListMutex(nullptr),
     _disableLeakReporting(false),
     _argc(0),
-    _argv(NULL)
+    _argv(nullptr)
 {
     FastOS_ProcessInterface::_app = this;
     char * fadvise = getenv("VESPA_FADVISE_OPTIONS");
-    if (fadvise != NULL) {
+    if (fadvise != nullptr) {
         int fadviseOptions(0);
         if (strstr(fadvise, "SEQUENTIAL")) { fadviseOptions |= POSIX_FADV_SEQUENTIAL; }
         if (strstr(fadvise, "RANDOM"))     { fadviseOptions |= POSIX_FADV_RANDOM; }
@@ -63,7 +63,7 @@ bool FastOS_ApplicationInterface::Init ()
             {
                 const char *errorMsg = FastOS_Socket::InitializeServices();
 
-                if(errorMsg == NULL)
+                if(errorMsg == nullptr)
                 {
                     _processListMutex = new FastOS_Mutex();
                     _threadPool = new FastOS_ThreadPool(128 * 1024);
@@ -91,19 +91,19 @@ bool FastOS_ApplicationInterface::Init ()
 
 void FastOS_ApplicationInterface::Cleanup ()
 {
-    if(_threadPool != NULL)
+    if(_threadPool != nullptr)
     {
         //      printf("Closing threadpool...\n");
         _threadPool->Close();
         //      printf("Deleting threadpool...\n");
         delete _threadPool;
-        _threadPool = NULL;
+        _threadPool = nullptr;
     }
 
-    if(_processListMutex != NULL)
+    if(_processListMutex != nullptr)
     {
         delete _processListMutex;
-        _processListMutex = NULL;
+        _processListMutex = nullptr;
     }
 
     FastOS_Socket::CleanupServices();
@@ -139,10 +139,10 @@ OnReceivedIPCMessage (const void *data, size_t length)
 void FastOS_ApplicationInterface::
 AddChildProcess (FastOS_ProcessInterface *node)
 {
-    node->_prev = NULL;
+    node->_prev = nullptr;
     node->_next = _processList;
 
-    if(_processList != NULL)
+    if(_processList != nullptr)
         _processList->_prev = node;
 
     _processList = node;
@@ -159,11 +159,11 @@ RemoveChildProcess (FastOS_ProcessInterface *node)
     if(node->_next)
     {
         node->_next->_prev = node->_prev;
-        node->_next = NULL;
+        node->_next = nullptr;
     }
 
-    if(node->_prev != NULL)
-        node->_prev = NULL;
+    if(node->_prev != nullptr)
+        node->_prev = nullptr;
 }
 
 bool
diff --git a/fastos/src/vespa/fastos/dynamiclibrary.h b/fastos/src/vespa/fastos/dynamiclibrary.h
index b0bf5730405..15cc28fa130 100644
--- a/fastos/src/vespa/fastos/dynamiclibrary.h
+++ b/fastos/src/vespa/fastos/dynamiclibrary.h
@@ -34,7 +34,7 @@ public:
      * @param libname the name of the library to open
      * @return Boolean success/failure
      */
-    virtual bool Open(const char *libname = NULL) = 0;
+    virtual bool Open(const char *libname = nullptr) = 0;
 
     /**
      * Close (unload) the library.
@@ -45,7 +45,7 @@ public:
     /**
      * Find the address of a symbol in the library.
      * @param symbol Name of symbol to find
-     * @return Address of the symbol, or NULL if an error has occurred
+     * @return Address of the symbol, or nullptr if an error has occurred
      */
     virtual void * GetSymbol(const char *symbol) const = 0;
 
diff --git a/fastos/src/vespa/fastos/file.cpp b/fastos/src/vespa/fastos/file.cpp
index 8f164c2a522..42ca432329d 100644
--- a/fastos/src/vespa/fastos/file.cpp
+++ b/fastos/src/vespa/fastos/file.cpp
@@ -27,7 +27,7 @@ DirectIOException::DirectIOException(const char * fileName, const void * buffer,
 
 DirectIOException::~DirectIOException() {}
 
-FastOS_FileInterface::FailedHandler FastOS_FileInterface::_failedHandler = NULL;
+FastOS_FileInterface::FailedHandler FastOS_FileInterface::_failedHandler = nullptr;
 int FastOS_FileInterface::_defaultFAdviseOptions = POSIX_FADV_NORMAL;
 
 static const size_t MAX_WRITE_CHUNK_SIZE = 0x4000000; // 64 MB
@@ -35,12 +35,12 @@ static const size_t MAX_WRITE_CHUNK_SIZE = 0x4000000; // 64 MB
 FastOS_FileInterface::FastOS_FileInterface(const char *filename)
     : _fAdviseOptions(_defaultFAdviseOptions),
       _writeChunkSize(MAX_WRITE_CHUNK_SIZE),
-      _filename(NULL),
+      _filename(nullptr),
       _openFlags(0),
       _directIOEnabled(false),
       _syncWritesEnabled(false)
 {
-    if (filename != NULL)
+    if (filename != nullptr)
         SetFileName(filename);
 }
 
@@ -200,7 +200,7 @@ FastOS_FileInterface::MemoryMapPtr(int64_t position) const
 {
     // Only subclases with support for memory mapping do something here.
     (void) position;
-    return NULL;
+    return nullptr;
 }
 
 
@@ -218,8 +218,8 @@ FastOS_FileInterface::CopyFile( const char *src, const char *dst )
     FastOS_StatInfo statInfo;
     bool success = false;
 
-    if ( src != NULL &&
-        dst != NULL &&
+    if ( src != nullptr &&
+        dst != nullptr &&
         strcmp(src, dst) != 0 &&
         FastOS_File::Stat( src, &statInfo )) {
 
@@ -233,7 +233,7 @@ FastOS_FileInterface::CopyFile( const char *src, const char *dst )
                 bufSize = static_cast<unsigned int>(bufSizeBound);
             char *tmpBuf = new char[ bufSize ];
 
-            if ( tmpBuf != NULL ) {
+            if ( tmpBuf != nullptr ) {
                 int64_t copied = 0;
                 success = true;
                 do {
@@ -278,7 +278,7 @@ FastOS_FileInterface::MoveFile(const char* src, const char* dst)
 
 void
 FastOS_FileInterface::EmptyDirectory( const char *dir,
-                                     const char *keepFile /* = NULL */ )
+                                     const char *keepFile /* = nullptr */ )
 {
     FastOS_StatInfo statInfo;
     if (!FastOS_File::Stat(dir, &statInfo))
@@ -288,7 +288,7 @@ FastOS_FileInterface::EmptyDirectory( const char *dir,
     while (dirScan.ReadNext()) {
         if (strcmp(dirScan.GetName(), ".") != 0 &&
             strcmp(dirScan.GetName(), "..") != 0 &&
-            (keepFile == NULL || strcmp(dirScan.GetName(), keepFile) != 0))
+            (keepFile == nullptr || strcmp(dirScan.GetName(), keepFile) != 0))
         {
             std::string name = dir;
             name += GetPathSeparator();
@@ -347,7 +347,7 @@ FastOS_FileInterface::MakeDirIfNotPresentOrExit(const char *name)
 void
 FastOS_FileInterface::SetFileName(const char *filename)
 {
-    if (_filename != NULL) {
+    if (_filename != nullptr) {
         free(_filename);
     }
 
@@ -358,7 +358,7 @@ FastOS_FileInterface::SetFileName(const char *filename)
 const char *
 FastOS_FileInterface::GetFileName() const
 {
-    return (_filename != NULL) ? _filename : "";
+    return (_filename != nullptr) ? _filename : "";
 }
 
 
diff --git a/fastos/src/vespa/fastos/file.h b/fastos/src/vespa/fastos/file.h
index 00ba61b793f..43e10fcd120 100644
--- a/fastos/src/vespa/fastos/file.h
+++ b/fastos/src/vespa/fastos/file.h
@@ -181,7 +181,7 @@ public:
      * @param  keepFile a 'const char *' value. If supplied, leave files with
      *                  this name alone.
      */
-    static void EmptyDirectory( const char *dir, const char *keepFile = NULL);
+    static void EmptyDirectory( const char *dir, const char *keepFile = nullptr);
 
     /**
      * Make a directory (special compatibility version)
@@ -205,7 +205,7 @@ public:
      * later using @ref SetFileName() or @ref Open().
      * @param filename  a filename (optional)
      */
-    FastOS_FileInterface(const char *filename=NULL);
+    FastOS_FileInterface(const char *filename=nullptr);
 
     /**
      * Destructor. If the current file is open, the destructor will close
@@ -243,7 +243,7 @@ public:
      *                     @ref Open().
      * @return Boolean success/failure
      */
-    virtual bool Open(unsigned int openFlags, const char *filename=NULL) = 0;
+    virtual bool Open(unsigned int openFlags, const char *filename=nullptr) = 0;
 
     /**
      * Open a file for read/write access. The file will be created if it does
@@ -254,7 +254,7 @@ public:
      *                       @ref SetFileName() or a previous call to @ref Open().
      * @return Boolean success/failure
      */
-    bool OpenReadWrite(const char *filename=NULL);
+    bool OpenReadWrite(const char *filename=nullptr);
 
     /**
      * Open a file for read/write access. This method fails if the file does
@@ -267,7 +267,7 @@ public:
      *                         @ref Open().
      * @return Boolean success/failure
      */
-    bool OpenExisting(bool abortIfNotExist=false, const char *filename=NULL);
+    bool OpenExisting(bool abortIfNotExist=false, const char *filename=nullptr);
 
     /**
      * Open a file for read access. This method fails if the file does
@@ -280,7 +280,7 @@ public:
      *                         @ref Open().
      * @return Boolean success/failure
      */
-    bool OpenReadOnlyExisting (bool abortIfNotExist=false, const char *filename=NULL);
+    bool OpenReadOnlyExisting (bool abortIfNotExist=false, const char *filename=nullptr);
 
     /**
      * Open a file for write access. If the file does not exist, it is created.
@@ -292,7 +292,7 @@ public:
      *                         @ref Open().
      * @return Boolean success/failure
      */
-    bool OpenWriteOnlyTruncate(const char *filename=NULL);
+    bool OpenWriteOnlyTruncate(const char *filename=nullptr);
 
     /**
      * Open a file for write access. This method fails if the file does
@@ -305,7 +305,7 @@ public:
      *                         @ref Open().
      * @return Boolean success/failure
      */
-    bool OpenWriteOnlyExisting (bool abortIfNotExist=false, const char *filename=NULL);
+    bool OpenWriteOnlyExisting (bool abortIfNotExist=false, const char *filename=nullptr);
 
     /**
      * Open a file for read-access only. This method fails if the file does
@@ -316,7 +316,7 @@ public:
      *                       @ref SetFileName() or a previous call to @ref Open().
      * @return Boolean success/failure
      */
-    bool OpenReadOnly(const char *filename=NULL);
+    bool OpenReadOnly(const char *filename=nullptr);
 
     /**
      * Open a file for write-access only.  The file will be created if it does
@@ -327,7 +327,7 @@ public:
      *                       @ref SetFileName() or a previous call to @ref Open().
      * @return Boolean success/failure
      */
-    bool OpenWriteOnly(const char *filename=NULL);
+    bool OpenWriteOnly(const char *filename=nullptr);
 
     bool OpenStdin();
 
@@ -567,7 +567,7 @@ public:
      *                           from malloc will be saved.  Use free() with
      *                           this pointer to deallocate the buffer.
      *                           This value is always set.
-     * @return Alligned pointer value or NULL if out of memory
+     * @return Alligned pointer value or nullptr if out of memory
      */
     virtual void *AllocateDirectIOBuffer(size_t byteSize, void *&realPtr);
 
@@ -581,7 +581,7 @@ public:
     /**
      * Inquiry about where in memory file data is located.
      * @return location of file data in memory.  If the file is not mapped,
-     * NULL is returned.
+     * nullptr is returned.
      */
     virtual void *MemoryMapPtr(int64_t position) const;
 
diff --git a/fastos/src/vespa/fastos/linux_file.cpp b/fastos/src/vespa/fastos/linux_file.cpp
index 3817e337490..08dc78585ec 100644
--- a/fastos/src/vespa/fastos/linux_file.cpp
+++ b/fastos/src/vespa/fastos/linux_file.cpp
@@ -32,7 +32,7 @@ ssize_t
 FastOS_Linux_File::readInternal(int fh, void *buffer, size_t length, int64_t readOffset)
 {
     ssize_t readResult = ::pread(fh, buffer, length, readOffset);
-    if (readResult < 0 && _failedHandler != NULL) {
+    if (readResult < 0 && _failedHandler != nullptr) {
         int error = errno;
         const char *fileName = GetFileName();
         _failedHandler("read", fileName, error, readOffset, length, readResult);
@@ -46,7 +46,7 @@ ssize_t
 FastOS_Linux_File::readInternal(int fh, void *buffer, size_t length)
 {
     ssize_t readResult = ::read(fh, buffer, length);
-    if (readResult < 0 && _failedHandler != NULL) {
+    if (readResult < 0 && _failedHandler != nullptr) {
         int error = errno;
         int64_t readOffset = GetPosition();
         const char *fileName = GetFileName();
@@ -61,7 +61,7 @@ ssize_t
 FastOS_Linux_File::writeInternal(int fh, const void *buffer, size_t length, int64_t writeOffset)
 {
     ssize_t writeRes = ::pwrite(fh, buffer, length, writeOffset);
-    if (writeRes < 0 && _failedHandler != NULL) {
+    if (writeRes < 0 && _failedHandler != nullptr) {
         int error = errno;
         const char *fileName = GetFileName();
         _failedHandler("write", fileName, error, writeOffset, length, writeRes);
@@ -74,7 +74,7 @@ ssize_t
 FastOS_Linux_File::writeInternal(int fh, const void *buffer, size_t length)
 {
     ssize_t writeRes = ::write(fh, buffer, length);
-    if (writeRes < 0 && _failedHandler != NULL) {
+    if (writeRes < 0 && _failedHandler != nullptr) {
         int error = errno;
         int64_t writeOffset = GetPosition();
         const char *fileName = GetFileName();
diff --git a/fastos/src/vespa/fastos/linux_file.h b/fastos/src/vespa/fastos/linux_file.h
index 95f2b935958..d33884c872a 100644
--- a/fastos/src/vespa/fastos/linux_file.h
+++ b/fastos/src/vespa/fastos/linux_file.h
@@ -24,7 +24,7 @@ protected:
     int64_t _filePointer;   // Only maintained/used in directio mode
 
 public:
-    FastOS_Linux_File (const char *filename = NULL);
+    FastOS_Linux_File (const char *filename = nullptr);
     ~FastOS_Linux_File () {
         Close();
     }
diff --git a/fastos/src/vespa/fastos/process.cpp b/fastos/src/vespa/fastos/process.cpp
index a806799e933..cac491de1e1 100644
--- a/fastos/src/vespa/fastos/process.cpp
+++ b/fastos/src/vespa/fastos/process.cpp
@@ -9,13 +9,13 @@ FastOS_ProcessInterface::FastOS_ProcessInterface (const char *cmdLine,
                          FastOS_ProcessRedirectListener *stderrListener,
                          int bufferSize) :
     _extradoublehackforalignment(0.0),
-    _cmdLine(NULL),
+    _cmdLine(nullptr),
     _pipeStdin(pipeStdin),
     _stdoutListener(stdoutListener),
     _stderrListener(stderrListener),
     _bufferSize(bufferSize),
-    _next(NULL),
-    _prev(NULL)
+    _next(nullptr),
+    _prev(nullptr)
 {
     _cmdLine = strdup(cmdLine);
 }
diff --git a/fastos/src/vespa/fastos/process.h b/fastos/src/vespa/fastos/process.h
index 1810a730d9d..f0c1fcaa2a9 100644
--- a/fastos/src/vespa/fastos/process.h
+++ b/fastos/src/vespa/fastos/process.h
@@ -26,7 +26,7 @@ public:
      * You should assume that any thread can invoke this method.
      * For convenience the data buffer is always zero- terminated
      * (static_cast<uint8_t>(data[length]) = '\\0').
-     * When the pipe closes, the method is invoked with data = NULL
+     * When the pipe closes, the method is invoked with data = nullptr
      * and length = 0.
      * @param  data              Pointer to data
      * @param  length            Length of data block in bytes
@@ -76,7 +76,7 @@ public:
      * of PrefopenNoInherit.
      * @return              Internal data needed to cancel object inheritance.
      */
-    static void *PrefopenNoInherit (void) {return NULL;}
+    static void *PrefopenNoInherit (void) {return nullptr;}
 
     /**
      * Call this after opening files with fopen to avoid having
@@ -105,14 +105,14 @@ public:
      * @ref CreateWithShell to actually start the process.
      * @param  cmdLine           Command line
      * @param  pipeStdin         set to true in order to redirect stdin
-     * @param  stdoutListener    non-NULL to redirect stdout
-     * @param  stderrListener    non-NULL to redirect stderr
+     * @param  stdoutListener    non-nullptr to redirect stdout
+     * @param  stderrListener    non-nullptr to redirect stderr
      * @param  bufferSize        Size of redirect buffers
      */
     FastOS_ProcessInterface (const char *cmdLine,
                              bool pipeStdin = false,
-                             FastOS_ProcessRedirectListener *stdoutListener = NULL,
-                             FastOS_ProcessRedirectListener *stderrListener = NULL,
+                             FastOS_ProcessRedirectListener *stdoutListener = nullptr,
+                             FastOS_ProcessRedirectListener *stderrListener = nullptr,
                              int bufferSize = 65535);
 
     /**
@@ -154,7 +154,7 @@ public:
     /**
      * If you are redirecting the standard input stream of the process,
      * use this method to write data. To close the input stream,
-     * invoke @ref WriteStdin with data=NULL. If the input stream
+     * invoke @ref WriteStdin with data=nullptr. If the input stream
      * is not redirected, @ref WriteStdin will fail.
      * @param  data              Pointer to data
      * @param  length            Length of data block in bytes
diff --git a/fastos/src/vespa/fastos/serversocket.h b/fastos/src/vespa/fastos/serversocket.h
index 93f1efe21fc..2e0690ffc3b 100644
--- a/fastos/src/vespa/fastos/serversocket.h
+++ b/fastos/src/vespa/fastos/serversocket.h
@@ -74,14 +74,14 @@ protected:
 
     /**
      * The socket factory to use for incoming connections.
-     * If this is NULL, the default action is to create an
+     * If this is nullptr, the default action is to create an
      * instance of the regular @ref FastOS_Socket.
      */
     FastOS_SocketFactory *_socketFactory;
 
     /**
      * Create socket for handling an incoming connection
-     * @return    Returns pointer to newly created socket, or NULL on
+     * @return    Returns pointer to newly created socket, or nullptr on
      *            failure.
      */
     FastOS_SocketInterface *CreateHandlerSocket();
@@ -98,8 +98,8 @@ public:
      * @param strictBindHostName   IP address or hostname for strict binding
      */
     FastOS_ServerSocket (int portnum, int backLog=5,
-                         FastOS_SocketFactory *socketFactory=NULL,
-                         const char *strictBindHostName=NULL)
+                         FastOS_SocketFactory *socketFactory=nullptr,
+                         const char *strictBindHostName=nullptr)
         : _portNumber(portnum),
           _backLog(backLog),
           _socketFactory(socketFactory),
@@ -126,7 +126,7 @@ public:
      * start to listen for incoming connections. You should
      * call @ref Listen() if you have supplied a pre-created listening
      * socket handle trough the constructor
-     * @ref FastOS_ServerSocket(int listenSocketHandle, FastOS_SocketFactory *socketFactory=NULL).
+     * @ref FastOS_ServerSocket(int listenSocketHandle, FastOS_SocketFactory *socketFactory=nullptr).
      * @return    Boolean success/failure
      */
     bool Listen ();
@@ -137,7 +137,7 @@ public:
      * Make sure you have a listening socket (see @ref Listen()) before
      * calling @ref Accept().
      * @return   Returns pointer to newly created socket object for the
-     *           connection that was accepted, or NULL on failure.
+     *           connection that was accepted, or nullptr on failure.
      */
     FastOS_SocketInterface *Accept ();
 
@@ -147,7 +147,7 @@ public:
      * Make sure you have a listening socket (see @ref Listen()) before
      * calling @ref AcceptPlain().
      * @return   Returns pointer to newly created socket object for the
-     *           connection that was accepted, or NULL on failure.
+     *           connection that was accepted, or nullptr on failure.
      */
     FastOS_Socket *AcceptPlain ();
 
@@ -157,7 +157,7 @@ public:
      * factory will be called to create a new socket object for the
      * connection.
      *
-     * SetSocketFactory(NULL) will enable the default socket factory
+     * SetSocketFactory(nullptr) will enable the default socket factory
      * mechanism which will create regular @ref FastOS_Socket instances
      * on accepted connections.
      */
diff --git a/fastos/src/vespa/fastos/socket.cpp b/fastos/src/vespa/fastos/socket.cpp
index 2732a38cf4c..c274f42bc68 100644
--- a/fastos/src/vespa/fastos/socket.cpp
+++ b/fastos/src/vespa/fastos/socket.cpp
@@ -14,8 +14,8 @@ FastOS_SocketInterface::FastOS_SocketInterface()
       _readPossible(false),
       _writePossible(false),
       _epolled(false),
-      _socketEvent(NULL),
-      _eventAttribute(NULL),
+      _socketEvent(nullptr),
+      _eventAttribute(nullptr),
       _socketEventArrayPos(-1),
       _address(),
       _socketHandle(-1),
@@ -30,8 +30,8 @@ FastOS_SocketInterface::FastOS_SocketInterface(int socketHandle, struct sockaddr
       _readPossible(false),
       _writePossible(false),
       _epolled(false),
-      _socketEvent(NULL),
-      _eventAttribute(NULL),
+      _socketEvent(nullptr),
+      _eventAttribute(nullptr),
       _socketEventArrayPos(-1),
       _address(),
       _socketHandle(-1),
@@ -145,10 +145,10 @@ void FastOS_SocketInterface::ConstructorWork ()
 {
     _socketHandle = -1;
     _epolled = false;
-    _socketEvent = NULL;
+    _socketEvent = nullptr;
     _readEventEnabled = false;
     _writeEventEnabled = false;
-    _eventAttribute = NULL;
+    _eventAttribute = nullptr;
     _socketEventArrayPos = -1;
 }
 
@@ -234,10 +234,10 @@ bool FastOS_SocketInterface::GetSoIntOpt(int option, int &value)
 
 void FastOS_SocketInterface::CleanupEvents ()
 {
-    if (_socketEvent != NULL) {
+    if (_socketEvent != nullptr) {
         _socketEvent->Detach(this);
         assert(!_epolled);
-        _socketEvent = NULL;
+        _socketEvent = nullptr;
     }
 }
 
@@ -287,7 +287,7 @@ FastOS_SocketInterface::getLastErrorString(void) {
 const char *
 FastOS_SocketInterface::InitializeServices(void) {
     FastOS_SocketEventObjects::InitializeClass();
-    return NULL;
+    return nullptr;
 }
 
 void FastOS_SocketInterface::CleanupServices () {
@@ -301,14 +301,14 @@ bool FastOS_SocketInterface::SetSocketEvent (FastOS_SocketEvent *event, void *at
 
     if (CreateIfNoSocketYet()) {
         if (_socketEvent != event) {
-            if (_socketEvent != NULL) {
+            if (_socketEvent != nullptr) {
                 // Disable events for this socket on the old SocketEvent
                 _socketEvent->Detach(this);
                 assert(!_epolled);
-                _socketEvent = NULL;
+                _socketEvent = nullptr;
             }
 
-            if (event != NULL) {
+            if (event != nullptr) {
                 event->Attach(this, _readEventEnabled, _writeEventEnabled);
                 _socketEvent = event;
             }
@@ -322,7 +322,7 @@ bool FastOS_SocketInterface::SetSocketEvent (FastOS_SocketEvent *event, void *at
 void FastOS_SocketInterface::EnableReadEvent (bool enabled) {
     if (_readEventEnabled == enabled) { return; }
     _readEventEnabled = enabled;
-    if (_socketEvent != NULL) {
+    if (_socketEvent != nullptr) {
         _socketEvent->EnableEvent(this, _readEventEnabled, _writeEventEnabled);
     }
 }
@@ -337,7 +337,7 @@ void FastOS_SocketInterface::EnableReadEvent (bool enabled) {
 void FastOS_SocketInterface::EnableWriteEvent (bool enabled) {
     if (_writeEventEnabled == enabled) { return; }
     _writeEventEnabled = enabled;
-    if (_socketEvent != NULL) {
+    if (_socketEvent != nullptr) {
         _socketEvent->EnableEvent(this, _readEventEnabled, _writeEventEnabled);
     }
 }
diff --git a/fastos/src/vespa/fastos/socket.h b/fastos/src/vespa/fastos/socket.h
index 6f4650ab64a..31b8903a4e4 100644
--- a/fastos/src/vespa/fastos/socket.h
+++ b/fastos/src/vespa/fastos/socket.h
@@ -244,11 +244,11 @@ public:
      * @param  attribute   Event attribute pointer
      * @return Boolean success/failure.
      */
-    bool SetSocketEvent (FastOS_SocketEvent *event, void *attribute=NULL);
+    bool SetSocketEvent (FastOS_SocketEvent *event, void *attribute=nullptr);
 
     /**
      * Get socket event object
-     * @return             Associated socket event object or NULL
+     * @return             Associated socket event object or nullptr
      */
     FastOS_SocketEvent *GetSocketEvent () { return _socketEvent; }
 
diff --git a/fastos/src/vespa/fastos/socketevent.cpp b/fastos/src/vespa/fastos/socketevent.cpp
index e3bc7d28888..a80cb015782 100644
--- a/fastos/src/vespa/fastos/socketevent.cpp
+++ b/fastos/src/vespa/fastos/socketevent.cpp
@@ -6,7 +6,7 @@
 #include <unistd.h>
 
 
-FastOS_SocketEventObjects *FastOS_SocketEventObjects::_objects = NULL;
+FastOS_SocketEventObjects *FastOS_SocketEventObjects::_objects = nullptr;
 FastOS_Mutex FastOS_SocketEventObjects::_listMutex;
 int FastOS_SocketEventObjects::_objectCount = 0;
 bool FastOS_SocketEventObjects::_initialized = false;
@@ -17,12 +17,12 @@ FastOS_SocketEvent::FastOS_SocketEvent () :
     _socketsInArray(0),
     _getEventsIndex(0),
     _wokeUp(false),
-    _objs(NULL)
+    _objs(nullptr)
 {
 
     _objs = FastOS_SocketEventObjects::ObtainObject(this);
 
-    if(_objs != NULL) {
+    if(_objs != nullptr) {
         if(_objs->_initOk) {
         }
     }
@@ -57,19 +57,19 @@ FastOS_SocketEventObjects *FastOS_SocketEventObjects::ObtainObject (FastOS_Socke
     FastOS_SocketEventObjects *node;
     _listMutex.Lock();
 
-    if(_objects == NULL)
+    if(_objects == nullptr)
     {
         _objectCount++;
         _listMutex.Unlock();
 
         node = new FastOS_SocketEventObjects(event);
-        node->_next = NULL;
+        node->_next = nullptr;
     }
     else
     {
         node = _objects;
         _objects = node->_next;
-        node->_next = NULL;
+        node->_next = nullptr;
 
         _listMutex.Unlock();
     }
@@ -79,7 +79,7 @@ FastOS_SocketEventObjects *FastOS_SocketEventObjects::ObtainObject (FastOS_Socke
 
 void FastOS_SocketEventObjects::ReleaseObject (FastOS_SocketEventObjects *node)
 {
-    if (node != NULL)
+    if (node != nullptr)
         node->ReleasedCleanup();
     _listMutex.Lock();
 
@@ -99,7 +99,7 @@ bool
 FastOS_SocketEvent::epollInit()
 {
     _epollfd = epoll_create(4093);
-    if (_epollfd != -1 && _objs != NULL && _objs->_initOk) {
+    if (_epollfd != -1 && _objs != nullptr && _objs->_initOk) {
         epoll_event evt;
         evt.events = EPOLLIN;
         evt.data.ptr = 0;
@@ -153,7 +153,7 @@ FastOS_SocketEvent::epollWait(bool &error, int msTimeout)
     for (int i = 0; i < res; ++i) {
         const epoll_event &evt = _epollEvents[i];
         FastOS_SocketInterface *sock = (FastOS_SocketInterface *) evt.data.ptr;
-        if (sock == NULL) {
+        if (sock == nullptr) {
             HandleWakeUp();
         } else {
             sock->_readPossible  = sock->_readEventEnabled &&
@@ -182,7 +182,7 @@ FastOS_SocketEvent::epollGetEvents(bool *wakeUp, int msTimeout,
         const epoll_event &evt = _epollEvents[i];
         FastOS_IOEvent &appEvt = events[idx];
         FastOS_SocketInterface *sock = (FastOS_SocketInterface *) evt.data.ptr;
-        if (sock == NULL) {
+        if (sock == nullptr) {
             HandleWakeUp(); // sets _wokeUp
         } else {
             appEvt._readOccurred = sock->_readEventEnabled &&
@@ -227,7 +227,7 @@ void FastOS_SocketEventObjects::ClassCleanup(void)
     {
         FastOS_SocketEventObjects *node = _objects;
 
-        if(node == NULL)
+        if(node == nullptr)
             break;
         else
         {
@@ -241,11 +241,11 @@ void FastOS_SocketEventObjects::ClassCleanup(void)
 
 
 FastOS_SocketEventObjects::FastOS_SocketEventObjects(FastOS_SocketEvent *event)
-    : _next(NULL),
+    : _next(nullptr),
       _initOk(false),
-      _socketArray(NULL),
+      _socketArray(nullptr),
       _socketArrayAllocSize(0u),
-      _pollfds(NULL),
+      _pollfds(nullptr),
       _pollfdsAllocSize(0)
 {
     // Connect ourselves to the socketevent object.
@@ -259,12 +259,12 @@ FastOS_SocketEventObjects::ReleasedCleanup(void)
 {
     if (_socketArrayAllocSize > 16) {
         delete [] _socketArray;
-        _socketArray = NULL;
+        _socketArray = nullptr;
         _socketArrayAllocSize = 0;
     }
     if (_pollfdsAllocSize > 16) {
         free(_pollfds);
-        _pollfds = NULL;
+        _pollfds = nullptr;
         _pollfdsAllocSize = 0;
     }
 }
diff --git a/fastos/src/vespa/fastos/socketevent.h b/fastos/src/vespa/fastos/socketevent.h
index 6ed6b73a86c..5e457908ace 100644
--- a/fastos/src/vespa/fastos/socketevent.h
+++ b/fastos/src/vespa/fastos/socketevent.h
@@ -87,7 +87,7 @@ public:
  *       FastOS_SocketEvent socketEvent;
  *
  *       // Walk through single-linked list of connections
- *       for(conn=connections; conn!=NULL; conn = conn->_next)
+ *       for(conn=connections; conn!=nullptr; conn = conn->_next)
  *       {
  *          // Associate each socket with socketEvent
  *          conn->_socket->SetSocketEvent(&socketEvent);
@@ -105,7 +105,7 @@ public:
  *          if(socketEvent.Wait(200))
  *          {
  *             // Walk through list of connections
- *             for(conn=connections; conn!=NULL; conn = conn->_next)
+ *             for(conn=connections; conn!=nullptr; conn = conn->_next)
  *             {
  *                // For each socket, check for read event
  *                if(socketEvent.QueryReadEvent(conn->_socket))
@@ -172,7 +172,7 @@ public:
         if (_epollfd == -1) {
             return false;
         }
-        return (_objs != NULL) ? _objs->_initOk : false;
+        return (_objs != nullptr) ? _objs->_initOk : false;
     }
 
     /**
diff --git a/fastos/src/vespa/fastos/thread.cpp b/fastos/src/vespa/fastos/thread.cpp
index 484746a9b0d..3cd3bb4b85b 100644
--- a/fastos/src/vespa/fastos/thread.cpp
+++ b/fastos/src/vespa/fastos/thread.cpp
@@ -21,8 +21,8 @@ FastOS_ThreadPool::FastOS_ThreadPool(int stackSize, int maxThreads)
       _closeCalledFlag(false),
       _freeMutex(),
       _liveCond(),
-      _freeThreads(NULL),
-      _activeThreads(NULL),
+      _freeThreads(nullptr),
+      _activeThreads(nullptr),
       _numFree(0),
       _numActive(0),
       _numTerminated(0),
@@ -71,9 +71,9 @@ void FastOS_ThreadPool::FreeThread (FastOS_ThreadInterface *thread)
 
 void FastOS_ThreadPool::LinkOutThread (FastOS_ThreadInterface *thread, FastOS_ThreadInterface **listHead)
 {
-    if (thread->_prev != NULL)
+    if (thread->_prev != nullptr)
         thread->_prev->_next = thread->_next;
-    if (thread->_next != NULL)
+    if (thread->_next != nullptr)
         thread->_next->_prev = thread->_prev;
 
     if (thread == *listHead)
@@ -82,10 +82,10 @@ void FastOS_ThreadPool::LinkOutThread (FastOS_ThreadInterface *thread, FastOS_Th
 
 void FastOS_ThreadPool::LinkInThread (FastOS_ThreadInterface *thread, FastOS_ThreadInterface **listHead)
 {
-    thread->_prev = NULL;
+    thread->_prev = nullptr;
     thread->_next = *listHead;
 
-    if (*listHead != NULL)
+    if (*listHead != nullptr)
         (*listHead)->_prev = thread;
 
     *listHead  = thread;
@@ -108,12 +108,12 @@ void FastOS_ThreadPool::ActivateThread (FastOS_ThreadInterface *thread)
 // make this thread call parameter fcn when it becomes active.
 FastOS_ThreadInterface *FastOS_ThreadPool::NewThread (FastOS_Runnable *owner, void *arg)
 {
-    FastOS_ThreadInterface *thread=NULL;
+    FastOS_ThreadInterface *thread=nullptr;
 
     _freeMutex.Lock();
 
     if (!isClosed()) {
-        if ((thread = _freeThreads) != NULL) {
+        if ((thread = _freeThreads) != nullptr) {
             // Reusing thread entry
             _freeThreads = thread->_next;
             _numFree--;
@@ -134,7 +134,7 @@ FastOS_ThreadInterface *FastOS_ThreadPool::NewThread (FastOS_Runnable *owner, vo
 
                 thread = FastOS_Thread::CreateThread(this);
 
-                if (thread == NULL) {
+                if (thread == nullptr) {
                     _liveCond.Lock();
                     _numLive--;
                     if (_numLive == 0) {
@@ -145,14 +145,14 @@ FastOS_ThreadInterface *FastOS_ThreadPool::NewThread (FastOS_Runnable *owner, vo
 
                 _freeMutex.Lock();
 
-                if(thread != NULL)
+                if(thread != nullptr)
                     ActivateThread(thread);
             }
         }
     }
 
     _freeMutex.Unlock();
-    if(thread != NULL) {
+    if(thread != nullptr) {
         _liveCond.Lock();
         thread->Dispatch(owner, arg);
         _liveCond.Unlock();
@@ -169,12 +169,12 @@ void FastOS_ThreadPool::BreakThreads ()
     _freeMutex.Lock();
 
     // Notice all active threads that they should quit
-    for(thread=_activeThreads; thread != NULL; thread=thread->_next) {
+    for(thread=_activeThreads; thread != nullptr; thread=thread->_next) {
         thread->SetBreakFlag();
     }
 
     // Notice all free threads that they should quit
-    for(thread=_freeThreads; thread != NULL; thread=thread->_next) {
+    for(thread=_freeThreads; thread != nullptr; thread=thread->_next) {
         thread->SetBreakFlag();
     }
 
@@ -201,7 +201,7 @@ void FastOS_ThreadPool::DeleteThreads ()
     assert(_numActive == 0);
     assert(_numLive == 0);
 
-    while((thread = _freeThreads) != NULL) {
+    while((thread = _freeThreads) != nullptr) {
         LinkOutThread(thread, &_freeThreads);
         _numFree--;
         //      printf("deleting thread %p\n", thread);
@@ -243,7 +243,7 @@ void *FastOS_ThreadHook (void *arg)
     FastOS_ThreadInterface *thread = static_cast<FastOS_ThreadInterface *>(arg);
     thread->Hook();
 
-    return NULL;
+    return nullptr;
 }
 };
 
@@ -264,7 +264,7 @@ void FastOS_ThreadInterface::Hook ()
 
         _dispatched.Lock();             // BEGIN lock
 
-        while (_owner == NULL && !(finished = _pool->isClosed())) {
+        while (_owner == nullptr && !(finished = _pool->isClosed())) {
             _dispatched.Wait();
         }
 
@@ -280,8 +280,8 @@ void FastOS_ThreadInterface::Hook ()
             if (deleteOnCompletion) {
                 delete _owner;
             }
-            _owner = NULL;
-            _startArg = NULL;
+            _owner = nullptr;
+            _startArg = nullptr;
             _breakFlag = false;
             finished = _pool->isClosed();
 
@@ -343,7 +343,7 @@ FastOS_ThreadInterface *FastOS_ThreadInterface::CreateThread(FastOS_ThreadPool *
 
     if(!thread->Initialize(pool->GetStackSize(), pool->GetStackGuardSize())) {
         delete(thread);
-        thread = NULL;
+        thread = nullptr;
     }
 
     return thread;
@@ -360,16 +360,16 @@ void FastOS_ThreadInterface::Join ()
 // ----------------------------------------------------------------------
 
 FastOS_Runnable::FastOS_Runnable(void)
-    : _thread(NULL)
+    : _thread(nullptr)
 {
 }
 
 FastOS_Runnable::~FastOS_Runnable(void)
 {
-    //      assert(_thread == NULL);
+    //      assert(_thread == nullptr);
 }
 
 void FastOS_Runnable::Detach(void)
 {
-    _thread = NULL;
+    _thread = nullptr;
 }
diff --git a/fastos/src/vespa/fastos/thread.h b/fastos/src/vespa/fastos/thread.h
index b84708eb050..eb43fc6b664 100644
--- a/fastos/src/vespa/fastos/thread.h
+++ b/fastos/src/vespa/fastos/thread.h
@@ -158,9 +158,9 @@ public:
      * @param owner     Instance to be invoked by new thread.
      * @param arg       Arguments to be passed to new thread.
      *
-     * @return          Pointer to newly created thread or NULL on failure.
+     * @return          Pointer to newly created thread or nullptr on failure.
      */
-    FastOS_ThreadInterface *NewThread (FastOS_Runnable *owner, void *arg=NULL);
+    FastOS_ThreadInterface *NewThread (FastOS_Runnable *owner, void *arg=nullptr);
 
     /**
      * Get the stack size used for threads in this pool.
@@ -285,7 +285,7 @@ protected:
      * Create an operating system thread. In most cases you would want
      * to create threads using @ref FastOS_ThreadPool::NewThread() instead.
      * @param pool  The threadpool which is about to contain the new thread.
-     * @return      A new @ref FastOS_Thread or NULL on failure.
+     * @return      A new @ref FastOS_Thread or nullptr on failure.
      */
     static FastOS_ThreadInterface *CreateThread(FastOS_ThreadPool *pool);
 
@@ -325,11 +325,11 @@ public:
      */
     FastOS_ThreadInterface (FastOS_ThreadPool *pool)
         : _dispatched(),
-          _next(NULL),
-          _prev(NULL),
-          _owner(NULL),
+          _next(nullptr),
+          _prev(nullptr),
+          _owner(nullptr),
           _pool(pool),
-          _startArg(NULL),
+          _startArg(nullptr),
           _breakFlag(false),
           _active(false),
           _runningCond()
@@ -492,7 +492,7 @@ public:
 
     FastOS_ThreadInterface *GetThread(void)             { return _thread; }
     const FastOS_ThreadInterface *GetThread(void) const { return _thread; }
-    bool HasThread(void)                          const { return _thread != NULL; }
+    bool HasThread(void)                          const { return _thread != nullptr; }
     void Detach(void);
 };
 
diff --git a/fastos/src/vespa/fastos/timestamp.cpp b/fastos/src/vespa/fastos/timestamp.cpp
index da0aa6bbd01..f967ea5aade 100644
--- a/fastos/src/vespa/fastos/timestamp.cpp
+++ b/fastos/src/vespa/fastos/timestamp.cpp
@@ -32,7 +32,7 @@ TimeStamp::asString(double timeInSeconds)
 int64_t ClockSystem::now()
 {
     struct timeval timeNow;
-    gettimeofday(&timeNow, NULL);
+    gettimeofday(&timeNow, nullptr);
     int64_t ns = timeNow.tv_sec;
     ns *= TimeStamp::NANO;
     ns += timeNow.tv_usec*1000;
diff --git a/fastos/src/vespa/fastos/unix_app.cpp b/fastos/src/vespa/fastos/unix_app.cpp
index 5916017e95c..7682b2d5b8f 100644
--- a/fastos/src/vespa/fastos/unix_app.cpp
+++ b/fastos/src/vespa/fastos/unix_app.cpp
@@ -17,8 +17,8 @@
 
 
 FastOS_UNIX_Application::FastOS_UNIX_Application ()
-    : _processStarter(NULL),
-      _ipcHelper(NULL)
+    : _processStarter(nullptr),
+      _ipcHelper(nullptr)
 {
 }
 
@@ -71,7 +71,7 @@ bool FastOS_UNIX_Application::
 SendIPCMessage (FastOS_UNIX_Process *xproc, const void *buffer,
                 int length)
 {
-    if(_ipcHelper == NULL)
+    if(_ipcHelper == nullptr)
         return false;
     return _ipcHelper->SendMessage(xproc, buffer, length);
 }
@@ -80,9 +80,9 @@ SendIPCMessage (FastOS_UNIX_Process *xproc, const void *buffer,
 bool FastOS_UNIX_Application::
 SendParentIPCMessage (const void *data, size_t length)
 {
-    if(_ipcHelper == NULL)
+    if(_ipcHelper == nullptr)
         return false;
-    return _ipcHelper->SendMessage(NULL, data, length);
+    return _ipcHelper->SendMessage(nullptr, data, length);
 }
 
 
@@ -95,7 +95,7 @@ bool FastOS_UNIX_Application::PreThreadInit ()
         act.sa_handler = SIG_IGN;
         sigemptyset(&act.sa_mask);
         act.sa_flags = 0;
-        sigaction(SIGPIPE, &act, NULL);
+        sigaction(SIGPIPE, &act, nullptr);
 
         if (useProcessStarter()) {
             _processStarter = new FastOS_UNIX_ProcessStarter(this);
@@ -120,7 +120,7 @@ bool FastOS_UNIX_Application::Init ()
         int ipcDescriptor = -1;
 
         char *env = getenv("FASTOS_IPC_PARENT");
-        if(env != NULL)
+        if(env != nullptr)
         {
             int commaCount=0;
             int notDigitCount=0;
@@ -158,15 +158,15 @@ bool FastOS_UNIX_Application::Init ()
 
 void FastOS_UNIX_Application::Cleanup ()
 {
-    if(_ipcHelper != NULL)
+    if(_ipcHelper != nullptr)
         _ipcHelper->Exit();
 
-    if (_processStarter != NULL) {
+    if (_processStarter != nullptr) {
         if (_processListMutex) ProcessLock();
         _processStarter->Stop();
         if (_processListMutex) ProcessUnlock();
         delete _processStarter;
-        _processStarter = NULL;
+        _processStarter = nullptr;
     }
 
     FastOS_ApplicationInterface::Cleanup();
@@ -181,13 +181,13 @@ FastOS_UNIX_Application::GetProcessStarter ()
 void FastOS_UNIX_Application::
 AddToIPCComm (FastOS_UNIX_Process *process)
 {
-    if(_ipcHelper != NULL)
+    if(_ipcHelper != nullptr)
         _ipcHelper->AddProcess(process);
 }
 
 void FastOS_UNIX_Application::
 RemoveFromIPCComm (FastOS_UNIX_Process *process)
 {
-    if(_ipcHelper != NULL)
+    if(_ipcHelper != nullptr)
         _ipcHelper->RemoveProcess(process);
 }
diff --git a/fastos/src/vespa/fastos/unix_cond.cpp b/fastos/src/vespa/fastos/unix_cond.cpp
index f2e541055ff..5eb1f5b0218 100644
--- a/fastos/src/vespa/fastos/unix_cond.cpp
+++ b/fastos/src/vespa/fastos/unix_cond.cpp
@@ -8,7 +8,7 @@ FastOS_UNIX_Cond::FastOS_UNIX_Cond(void)
     : FastOS_CondInterface(),
       _cond()
 {
-    pthread_cond_init(&_cond, NULL);
+    pthread_cond_init(&_cond, nullptr);
 }
 
 FastOS_UNIX_Cond::~FastOS_UNIX_Cond(void)
@@ -30,7 +30,7 @@ FastOS_UNIX_Cond::TimedWait(int milliseconds)
     struct timespec absTime;
     int error;
 
-    gettimeofday(&currentTime, NULL);
+    gettimeofday(&currentTime, nullptr);
 
     int64_t ns = (static_cast<int64_t>(currentTime.tv_sec) *
                   static_cast<int64_t>(1000 * 1000 * 1000) +
diff --git a/fastos/src/vespa/fastos/unix_dynamiclibrary.cpp b/fastos/src/vespa/fastos/unix_dynamiclibrary.cpp
index 75d3ee9fb27..f3d3aa35511 100644
--- a/fastos/src/vespa/fastos/unix_dynamiclibrary.cpp
+++ b/fastos/src/vespa/fastos/unix_dynamiclibrary.cpp
@@ -20,7 +20,7 @@ bool hasValidSuffix(const std::string & s)
 void
 FastOS_UNIX_DynamicLibrary::SetLibName(const char *libname)
 {
-    if (libname != NULL) {
+    if (libname != nullptr) {
         _libname = libname;
         if ( ! hasValidSuffix(_libname)) {
             _libname.append(FASTOS_DYNLIB_SUFFIX);
@@ -58,14 +58,14 @@ FastOS_UNIX_DynamicLibrary::Close()
     if (IsOpen()) {
         retcode = (dlclose(_handle) == 0);
         if (retcode)
-            _handle = NULL;
+            _handle = nullptr;
     }
 
     return retcode;
 }
 
 FastOS_UNIX_DynamicLibrary::FastOS_UNIX_DynamicLibrary(const char *libname) :
-    _handle(NULL),
+    _handle(nullptr),
     _libname("")
 {
     SetLibName(libname);
@@ -81,13 +81,13 @@ FastOS_UNIX_DynamicLibrary::Open(const char *libname)
 {
     if (! Close())
         return false;
-    if (libname != NULL) {
+    if (libname != nullptr) {
         SetLibName(libname);
     }
 
     _handle = dlopen(_libname.c_str(), RTLD_NOW);
 
-    if (_handle == NULL) {
+    if (_handle == nullptr) {
         // Prepend "lib" if neccessary...
         if (NormalizeLibName()) {
             // ...try to open again if a change was made.
@@ -95,7 +95,7 @@ FastOS_UNIX_DynamicLibrary::Open(const char *libname)
         }
     }
 
-    return (_handle != NULL);
+    return (_handle != nullptr);
 }
 
 void *
@@ -109,7 +109,7 @@ FastOS_UNIX_DynamicLibrary::GetLastErrorString() const
 {
     const char *errorString = dlerror();
     std::string e;
-    if (errorString != NULL) {
+    if (errorString != nullptr) {
         e = errorString;
     }
 
diff --git a/fastos/src/vespa/fastos/unix_dynamiclibrary.h b/fastos/src/vespa/fastos/unix_dynamiclibrary.h
index 13e86b1c8af..1c891ee5b6d 100644
--- a/fastos/src/vespa/fastos/unix_dynamiclibrary.h
+++ b/fastos/src/vespa/fastos/unix_dynamiclibrary.h
@@ -24,17 +24,17 @@ private:
     std::string  _libname;
 
 public:
-    FastOS_UNIX_DynamicLibrary(const char *libname = NULL);
+    FastOS_UNIX_DynamicLibrary(const char *libname = nullptr);
     ~FastOS_UNIX_DynamicLibrary();
 
     void SetLibName(const char *libname);
     bool NormalizeLibName(void);
     bool Close() override;
-    bool Open(const char *libname = NULL) override;
+    bool Open(const char *libname = nullptr) override;
     void * GetSymbol(const char *symbol) const override;
     std::string GetLastErrorString() const;
     const char * GetLibName() const { return _libname.c_str(); }
-    bool IsOpen()             const override { return (_handle != NULL); }
+    bool IsOpen()             const override { return (_handle != nullptr); }
 };
 
 
diff --git a/fastos/src/vespa/fastos/unix_file.h b/fastos/src/vespa/fastos/unix_file.h
index aa5ea4edb01..5702f511ca5 100644
--- a/fastos/src/vespa/fastos/unix_file.h
+++ b/fastos/src/vespa/fastos/unix_file.h
@@ -47,9 +47,9 @@ public:
     static int GetMaximumFilenameLength (const char *pathName);
     static int GetMaximumPathLength (const char *pathName);
 
-    FastOS_UNIX_File(const char *filename=NULL)
+    FastOS_UNIX_File(const char *filename=nullptr)
         : FastOS_FileInterface(filename),
-          _mmapbase(NULL),
+          _mmapbase(nullptr),
           _mmaplen(0),
           _filedes(-1),
           _mmapFlags(0),
@@ -66,18 +66,18 @@ public:
     }
 
     void *MemoryMapPtr(int64_t position) const override {
-        if (_mmapbase != NULL) {
+        if (_mmapbase != nullptr) {
             if (position < int64_t(_mmaplen)) {
                 return static_cast<void *>(static_cast<char *>(_mmapbase) + position);
             } else {  // This is an indication that the file size has changed and a remap/reopen must be done.
-                return NULL;
+                return nullptr;
             }
         } else {
-            return NULL;
+            return nullptr;
         }
     }
 
-    bool IsMemoryMapped() const override { return _mmapbase != NULL; }
+    bool IsMemoryMapped() const override { return _mmapbase != nullptr; }
     bool SetPosition(int64_t desiredPosition) override;
     int64_t GetPosition() override;
     int64_t GetSize() override;
diff --git a/fastos/src/vespa/fastos/unix_ipc.cpp b/fastos/src/vespa/fastos/unix_ipc.cpp
index f8cde75bc7a..695d395674f 100644
--- a/fastos/src/vespa/fastos/unix_ipc.cpp
+++ b/fastos/src/vespa/fastos/unix_ipc.cpp
@@ -118,7 +118,7 @@ SetBlocking (int fileDescriptor, bool doBlock)
 {
     bool rc=false;
 
-    int flags = fcntl(fileDescriptor, F_GETFL, NULL);
+    int flags = fcntl(fileDescriptor, F_GETFL, nullptr);
     if (flags != -1)
     {
         if(doBlock)
@@ -134,7 +134,7 @@ void FastOS_UNIX_IPCHelper::
 BuildPollCheck(bool isRead, int filedes,
                FastOS_RingBuffer *buffer, bool *check)
 {
-    if(buffer == NULL ||
+    if(buffer == nullptr ||
        filedes < 0 ||
        buffer->GetCloseFlag()) {
         *check = false;
@@ -154,7 +154,7 @@ void FastOS_UNIX_IPCHelper::
 PerformAsyncIO(void)
 {
     FastOS_ProcessInterface *node;
-    for(node = _app->GetProcessList(); node != NULL; node = node->_next)
+    for(node = _app->GetProcessList(); node != nullptr; node = node->_next)
     {
         FastOS_UNIX_Process *xproc = static_cast<FastOS_UNIX_Process *>(node);
 
@@ -187,7 +187,7 @@ void FastOS_UNIX_IPCHelper::
 BuildPollChecks(void)
 {
     FastOS_ProcessInterface *node;
-    for(node = _app->GetProcessList(); node != NULL; node = node->_next)
+    for(node = _app->GetProcessList(); node != nullptr; node = node->_next)
     {
         FastOS_UNIX_Process *xproc = static_cast<FastOS_UNIX_Process *>(node);
 
@@ -202,11 +202,11 @@ BuildPollChecks(void)
         }
     }
 
-    if(_appParentIPCDescriptor._writeBuffer.get() != NULL)
+    if(_appParentIPCDescriptor._writeBuffer.get() != nullptr)
         BuildPollCheck(false, _appParentIPCDescriptor._fd,
                        _appParentIPCDescriptor._writeBuffer.get(),
                        &_appParentIPCDescriptor._wantWrite);
-    if(_appParentIPCDescriptor._readBuffer.get() != NULL)
+    if(_appParentIPCDescriptor._readBuffer.get() != nullptr)
         BuildPollCheck(true, _appParentIPCDescriptor._fd,
                        _appParentIPCDescriptor._readBuffer.get(),
                        &_appParentIPCDescriptor._wantRead);
@@ -225,12 +225,12 @@ ResizePollArray(pollfd **fds, unsigned int *allocnfds)
     else
         newallocnfds = *allocnfds * 2;
     newfds = static_cast<pollfd *>(malloc(newallocnfds * sizeof(pollfd)));
-    assert(newfds != NULL);
+    assert(newfds != nullptr);
 
     if (*allocnfds > 0)
         memcpy(newfds, *fds, sizeof(pollfd) * *allocnfds);
 
-    if (*fds != NULL)
+    if (*fds != nullptr)
         free(*fds);
 
     *fds = newfds;
@@ -261,7 +261,7 @@ BuildPollArray(pollfd **fds, unsigned int *nfds, unsigned int *allocnfds)
     rfds->revents = 0;
     rfds++;
     pollIdx = 1;
-    for(node = _app->GetProcessList(); node != NULL; node = node->_next)
+    for(node = _app->GetProcessList(); node != nullptr; node = node->_next)
     {
         FastOS_UNIX_Process *xproc = static_cast<FastOS_UNIX_Process *>(node);
 
@@ -331,7 +331,7 @@ SavePollArray(pollfd *fds, unsigned int nfds)
 {
     FastOS_ProcessInterface *node;
 
-    for(node = _app->GetProcessList(); node != NULL; node = node->_next)
+    for(node = _app->GetProcessList(); node != nullptr; node = node->_next)
     {
         FastOS_UNIX_Process *xproc = static_cast<FastOS_UNIX_Process *>(node);
 
@@ -396,7 +396,7 @@ RemoveClosingProcesses(void)
 
     FastOS_ProcessInterface *node, *next;
 
-    for(node = _app->GetProcessList(); node != NULL; node = next)
+    for(node = _app->GetProcessList(); node != nullptr; node = next)
     {
         int type;
 
@@ -430,7 +430,7 @@ RemoveClosingProcesses(void)
 
         if(!stillBusy)
         {
-            if(xproc->_closing != NULL)
+            if(xproc->_closing != nullptr)
             {
                 // We already have the process lock at this point,
                 // so modifying the list is safe.
@@ -468,14 +468,14 @@ Run(FastOS_ThreadInterface *thisThread, void *arg)
     unsigned int nfds;
     unsigned int allocnfds;
 
-    fds = NULL;
+    fds = nullptr;
     nfds = 0;
     allocnfds = 0;
     for(;;)
     {
         // Deliver messages to from child processes and parent.
         _app->ProcessLock();
-        for(node = _app->GetProcessList(); node != NULL; node = node->_next)
+        for(node = _app->GetProcessList(); node != nullptr; node = node->_next)
         {
             FastOS_UNIX_Process *xproc = static_cast<FastOS_UNIX_Process *>(node);
             FastOS_UNIX_Process::DescriptorHandle &desc =
@@ -578,12 +578,12 @@ SendMessage (FastOS_UNIX_Process *xproc, const void *buffer,
     FastOS_RingBuffer *ipcBuffer;
 
     FastOS_UNIX_Process::DescriptorHandle &desc =
-        xproc != NULL ?
+        xproc != nullptr ?
         xproc->GetDescriptorHandle(FastOS_UNIX_Process::TYPE_IPC) :
         _appParentIPCDescriptor;
     ipcBuffer = desc._writeBuffer.get();
 
-    if(ipcBuffer != NULL) {
+    if(ipcBuffer != nullptr) {
         ipcBuffer->Lock();
 
         if(ipcBuffer->GetWriteSpace() >= int((length + sizeof(int)))) {
@@ -653,7 +653,7 @@ void FastOS_UNIX_IPCHelper::RemoveProcess (FastOS_UNIX_Process *xproc)
 
 void FastOS_UNIX_IPCHelper::DeliverMessages (FastOS_RingBuffer *buffer)
 {
-    if(buffer == NULL)
+    if(buffer == nullptr)
         return;
 
     buffer->Lock();
@@ -683,11 +683,11 @@ PipeData (FastOS_UNIX_Process *process,
 {
     FastOS_UNIX_Process::DescriptorHandle &desc = process->GetDescriptorHandle(type);
     FastOS_RingBuffer *buffer = desc._readBuffer.get();
-    if(buffer == NULL)
+    if(buffer == nullptr)
         return;
 
     FastOS_ProcessRedirectListener *listener = process->GetListener(type);
-    if(listener == NULL)
+    if(listener == nullptr)
         return;
 
     buffer->Lock();
diff --git a/fastos/src/vespa/fastos/unix_mutex.cpp b/fastos/src/vespa/fastos/unix_mutex.cpp
index 4d802f691ec..535a39ce592 100644
--- a/fastos/src/vespa/fastos/unix_mutex.cpp
+++ b/fastos/src/vespa/fastos/unix_mutex.cpp
@@ -7,7 +7,7 @@ FastOS_UNIX_Mutex::FastOS_UNIX_Mutex(void)
     : FastOS_MutexInterface(),
       _mutex()
 {
-    int error = pthread_mutex_init(&_mutex, NULL);
+    int error = pthread_mutex_init(&_mutex, nullptr);
     assert(error == 0);
     (void) error;
 }
diff --git a/fastos/src/vespa/fastos/unix_process.cpp b/fastos/src/vespa/fastos/unix_process.cpp
index 70e441c64db..df32cb935ff 100644
--- a/fastos/src/vespa/fastos/unix_process.cpp
+++ b/fastos/src/vespa/fastos/unix_process.cpp
@@ -172,7 +172,7 @@ public:
     static const char *
     NextArgument (const char *p,
                   const char **endArg,
-                  int *length = NULL);
+                  int *length = nullptr);
 
     static int CountArguments (const char *commandLine);
 
@@ -264,10 +264,10 @@ FastOS_UNIX_RealProcess::FastOS_UNIX_RealProcess(int streamMask)
       _runDir(),
       _stdoutRedirName(),
       _stderrRedirName(),
-      _path(NULL),
+      _path(nullptr),
       _pathProgBuf(),
-      _prev(NULL),
-      _next(NULL)
+      _prev(nullptr),
+      _next(nullptr)
 {
     _stdinDes[0] = _stdinDes[1] = -1;
     _stdoutDes[0] = _stdoutDes[1] = -1;
@@ -286,15 +286,15 @@ FastOS_UNIX_RealProcess::~FastOS_UNIX_RealProcess(void)
 void
 FastOS_UNIX_RealProcess::PrepareExecVPE(const char *prog)
 {
-    const char *path = NULL;
+    const char *path = nullptr;
 
     char defaultPath[] = ":/usr/ucb:/bin:/usr/bin";
 
-    if (strchr(prog, '/') != NULL) {
+    if (strchr(prog, '/') != nullptr) {
         path = "";
     } else {
         path = getenv("PATH");
-        if (path == NULL) path = defaultPath;
+        if (path == nullptr) path = defaultPath;
     }
     _path = path;
     _pathProgBuf.resize(strlen(prog) + 1 + strlen(path) + 1);
@@ -362,14 +362,14 @@ FastOS_UNIX_RealProcess::NextArgument (const char *p,
             for(;;)
             {
                 if (*p == '\0') {
-                    if (length != NULL)
+                    if (length != nullptr)
                         *length = p - nextArg;
                     break;
                 }
 
                 if (quoteChar != '\0') {
                     if (*p == quoteChar) {
-                        if (length != NULL)
+                        if (length != nullptr)
                             *length = p - nextArg;
                         p++;
                         break;
@@ -378,7 +378,7 @@ FastOS_UNIX_RealProcess::NextArgument (const char *p,
                 else
                 {
                     if (IsWhiteSpace(*p)) {
-                        if (length != NULL)
+                        if (length != nullptr)
                             *length = p - nextArg;
                         break;
                     }
@@ -391,7 +391,7 @@ FastOS_UNIX_RealProcess::NextArgument (const char *p,
         }
         p++;
     }
-    return NULL;
+    return nullptr;
 }
 
 
@@ -470,7 +470,7 @@ ForkAndExec(const char *command,
 
 
     int numArguments = 0;
-    char **execArgs = NULL;
+    char **execArgs = nullptr;
 
     if (!IsUsingShell()) {
         numArguments = CountArguments(command);
@@ -483,9 +483,9 @@ ForkAndExec(const char *command,
                 const char *arg = NextArgument(nextArg, &nextArg,
                                                &length);
 
-                if (arg == NULL) {
-                    // printf("ARG NULL\n");
-                    execArgs[i] = NULL;
+                if (arg == nullptr) {
+                    // printf("ARG nullptr\n");
+                    execArgs[i] = nullptr;
                     break;
                 }
                 // printf("argLen = %d\n", length);
@@ -497,7 +497,7 @@ ForkAndExec(const char *command,
             PrepareExecVPE(execArgs[0]);
         }
     }
-    if (process == NULL) {
+    if (process == nullptr) {
         processStarter->CloseProxyDescs(IsStdinPiped() ? _stdinDes[0] : -1,
                                         IsStdoutPiped() ? _stdoutDes[1] : -1,
                                         IsStderrPiped() ? _stderrDes[1] : -1,
@@ -542,7 +542,7 @@ ForkAndExec(const char *command,
 
         CloseDescriptor(_handshakeDes[0]);
         _handshakeDes[0] = -1;
-        if (process != NULL) {
+        if (process != nullptr) {
             if (!process->GetKeepOpenFilesIfDirectChild()) {
                 int fdlimit = sysconf(_SC_OPEN_MAX);
                 // Close everything else
@@ -571,7 +571,7 @@ ForkAndExec(const char *command,
             shExecArgs[0] = "sh";
             shExecArgs[1] = "-c";
             shExecArgs[2] = command;
-            shExecArgs[3] = NULL;
+            shExecArgs[3] = nullptr;
             execve("/bin/sh",
                    const_cast<char *const *>
                    (reinterpret_cast<const char *const *>
@@ -702,9 +702,9 @@ ForkAndExec(const char *command,
             rc = true;
         }
     }
-    if (execArgs != NULL) {
+    if (execArgs != nullptr) {
         char **arg = execArgs;
-        while (*arg != NULL) {
+        while (*arg != nullptr) {
             delete [] *arg;
             arg++;
         }
@@ -795,14 +795,14 @@ FastOS_UNIX_Process (const char *cmdLine, bool pipeStdin,
     _stdoutRedirName(),
     _stderrRedirName(),
     _killed(false),
-    _closing(NULL)
+    _closing(nullptr)
 {
     _descriptor[TYPE_IPC]._readBuffer.reset(new FastOS_RingBuffer(bufferSize));
     _descriptor[TYPE_IPC]._writeBuffer.reset(new FastOS_RingBuffer(bufferSize));
 
-    if (stdoutListener != NULL)
+    if (stdoutListener != nullptr)
         _descriptor[TYPE_STDOUT]._readBuffer.reset(new FastOS_RingBuffer(bufferSize));
-    if (stderrListener != NULL)
+    if (stderrListener != nullptr)
         _descriptor[TYPE_STDERR]._readBuffer.reset(new FastOS_RingBuffer(bufferSize));
 
     _app->ProcessLock();
@@ -865,8 +865,8 @@ bool FastOS_UNIX_Process::CreateInternal (bool useShell)
 {
     return GetProcessStarter()->CreateProcess(this, useShell,
                                               _pipeStdin,
-                                              _stdoutListener != NULL,
-                                              _stderrListener != NULL);
+                                              _stdoutListener != nullptr,
+                                              _stderrListener != nullptr);
 }
 
 bool FastOS_UNIX_Process::WriteStdin (const void *data, size_t length)
@@ -875,7 +875,7 @@ bool FastOS_UNIX_Process::WriteStdin (const void *data, size_t length)
     DescriptorHandle &desc = GetDescriptorHandle(TYPE_STDIN);
 
     if (desc._fd != -1) {
-        if (data == NULL) {
+        if (data == nullptr) {
             CloseDescriptor(TYPE_STDIN);
             rc = true;
         }
@@ -940,7 +940,7 @@ bool FastOS_UNIX_Process::InternalWait (int *returnCode,
 
 bool FastOS_UNIX_Process::Wait (int *returnCode, int timeOutSeconds)
 {
-    return InternalWait(returnCode, timeOutSeconds, NULL);
+    return InternalWait(returnCode, timeOutSeconds, nullptr);
 }
 
 bool FastOS_UNIX_Process::PollWait (int *returnCode, bool *stillRunning)
@@ -1054,10 +1054,10 @@ void FastOS_UNIX_ProcessStarter::WriteInt (int fd, int integer,
 void FastOS_UNIX_ProcessStarter::
 AddChildProcess (FastOS_UNIX_RealProcess *node)
 {
-    node->_prev = NULL;
+    node->_prev = nullptr;
     node->_next = _processList;
 
-    if (_processList != NULL)
+    if (_processList != nullptr)
         _processList->_prev = node;
     _processList = node;
 }
@@ -1072,11 +1072,11 @@ RemoveChildProcess (FastOS_UNIX_RealProcess *node)
 
     if (node->_next) {
         node->_next->_prev = node->_prev;
-        node->_next = NULL;
+        node->_next = nullptr;
     }
 
-    if (node->_prev != NULL)
-        node->_prev = NULL;
+    if (node->_prev != nullptr)
+        node->_prev = nullptr;
 }
 
 bool FastOS_UNIX_ProcessStarter::SendFileDescriptor (int fd)
@@ -1112,7 +1112,7 @@ bool FastOS_UNIX_ProcessStarter::SendFileDescriptor (int fd)
     msg.msg_accrightslen = sizeof(int);
 #endif
 
-    msg.msg_name = NULL;
+    msg.msg_name = nullptr;
     msg.msg_namelen = 0;
 
     char dummyData = '\0';
@@ -1149,7 +1149,7 @@ void FastOS_UNIX_ProcessStarter::StarterDoWait ()
 
         FastOS_UNIX_RealProcess *process, *next;
         for(process = FastOS_UNIX_ProcessStarter::_processList;
-            process != NULL; process = next)
+            process != nullptr; process = next)
         {
 
             // Need to do this here since we are deleting entries
@@ -1204,7 +1204,7 @@ void FastOS_UNIX_ProcessStarter::StarterDoDetachProcess ()
 
     FastOS_UNIX_RealProcess *process, *next;
     for(process = FastOS_UNIX_ProcessStarter::_processList;
-        process != NULL; process = next) {
+        process != nullptr; process = next) {
 
         // Need to do this here since we are deleting entries
         next = process->_next;
@@ -1342,7 +1342,7 @@ void FastOS_UNIX_ProcessStarter::StarterDoCreateProcess ()
             pid_t processId = -1;
             if (process->ForkAndExec(cmdLine,
                                      environmentVariables,
-                                     NULL,
+                                     nullptr,
                                      this))
             {
                 processId = process->GetProcessID();
@@ -1359,7 +1359,7 @@ void FastOS_UNIX_ProcessStarter::StarterDoCreateProcess ()
     if (!rc) delete process;
 
     char **pe = environmentVariables;
-    while(*pe != NULL) {
+    while(*pe != nullptr) {
         delete [] *pe++;
     }
     delete [] environmentVariables;
@@ -1415,7 +1415,7 @@ bool FastOS_UNIX_ProcessStarter::CreateSocketPairs ()
 
 FastOS_UNIX_ProcessStarter::FastOS_UNIX_ProcessStarter (FastOS_ApplicationInterface *app)
     : _app(app),
-      _processList(NULL),
+      _processList(nullptr),
       _pid(-1),
       _starterSocket(-1),
       _mainSocket(-1),
@@ -1503,7 +1503,7 @@ int FastOS_UNIX_ProcessStarter::ReadFileDescriptor ()
     msg.msg_accrightslen = sizeof(int);
 #endif
 
-    msg.msg_name = NULL;
+    msg.msg_name = nullptr;
     msg.msg_namelen = 0;
 
     char dummyData = '\0';
@@ -1521,7 +1521,7 @@ int FastOS_UNIX_ProcessStarter::ReadFileDescriptor ()
     //   printf("recvmsgrc = %d\n", recvmsgrc);
 
 #ifndef FASTOS_HAVE_ACCRIGHTSLEN
-    if ((cmptr = CMSG_FIRSTHDR(&msg)) != NULL &&
+    if ((cmptr = CMSG_FIRSTHDR(&msg)) != nullptr &&
         cmptr->cmsg_len == CMSG_LEN(sizeof(int)))
     {
         if (cmptr->cmsg_level != SOL_SOCKET)
@@ -1594,7 +1594,7 @@ char ** FastOS_UNIX_ProcessStarter::ReceiveEnvironmentVariables ()
         else
             fillIndex++;
     }
-    myEnvironment[fillIndex] = NULL;
+    myEnvironment[fillIndex] = nullptr;
 
     return myEnvironment;
 }
@@ -1605,7 +1605,7 @@ void FastOS_UNIX_ProcessStarter::SendEnvironmentVariables ()
     int numEnvVars = 0;
     char **pe = environ;
 
-    while(*pe++ != NULL)
+    while(*pe++ != nullptr)
         numEnvVars++;
 
     WriteInt(_mainSocket, numEnvVars);
@@ -1619,7 +1619,7 @@ void FastOS_UNIX_ProcessStarter::SendEnvironmentVariables ()
         const char *envString = "";
         if (!gotNull) {
             envString = *pe++;
-            if (envString == NULL) {
+            if (envString == nullptr) {
                 envString = "";
                 gotNull = true;
             }
@@ -1674,7 +1674,7 @@ FastOS_UNIX_ProcessStarter::
 CopyEnvironmentVariables(void)
 {
     char **env = environ;
-    while (*env != NULL)
+    while (*env != nullptr)
         env++;
     int numEnvVars = env - environ;
     char **newEnv = new char *[numEnvVars + 2];
@@ -1682,7 +1682,7 @@ CopyEnvironmentVariables(void)
 
     int fillIdx = 1;
     env = environ;
-    while (*env != NULL) {
+    while (*env != nullptr) {
         size_t len = strlen(*env);
         if (len > 0 &&
             strncmp(*env, "FASTOS_IPC_PARENT=", 18) != 0) {
@@ -1692,7 +1692,7 @@ CopyEnvironmentVariables(void)
         }
         env++;
     }
-    newEnv[fillIdx] = NULL;
+    newEnv[fillIdx] = nullptr;
     return newEnv;
 }
 
@@ -1702,7 +1702,7 @@ FastOS_UNIX_ProcessStarter::
 FreeEnvironmentVariables(char **env)
 {
     char **p = env;
-    while (*p != NULL) {
+    while (*p != nullptr) {
         delete [] *p;
         p++;
     }
@@ -1729,15 +1729,15 @@ CreateProcess (FastOS_UNIX_Process *process,
         FastOS_UNIX_RealProcess *rprocess =
             new FastOS_UNIX_RealProcess(process->BuildStreamMask(useShell));
         const char *runDir = process->GetRunDir();
-        if (runDir != NULL) {
+        if (runDir != nullptr) {
             rprocess->SetRunDir(runDir);            // Handover
         }
         const char *stdoutRedirName = process->GetStdoutRedirName();
-        if (stdoutRedirName != NULL) {
+        if (stdoutRedirName != nullptr) {
             rprocess->SetStdoutRedirName(stdoutRedirName);
         }
         const char *stderrRedirName = process->GetStderrRedirName();
-        if (stderrRedirName != NULL) {
+        if (stderrRedirName != nullptr) {
             rprocess->SetStderrRedirName(stderrRedirName);
         }
         char **env = CopyEnvironmentVariables();
@@ -1786,7 +1786,7 @@ CreateProcess (FastOS_UNIX_Process *process,
     SendEnvironmentVariables();
 
     const char *runDir = process->GetRunDir();
-    if (runDir != NULL) {
+    if (runDir != nullptr) {
         int runDirLength = strlen(runDir) + 1;
         WriteInt(_mainSocket, runDirLength);
         WriteBytes(_mainSocket, runDir, runDirLength);
@@ -1794,7 +1794,7 @@ CreateProcess (FastOS_UNIX_Process *process,
         WriteInt(_mainSocket, 0);
 
     const char *stdoutRedirName = process->GetStdoutRedirName();
-    if (stdoutRedirName != NULL) {
+    if (stdoutRedirName != nullptr) {
         int stdoutRedirNameLength = strlen(stdoutRedirName) + 1;
         WriteInt(_mainSocket, stdoutRedirNameLength);
         WriteBytes(_mainSocket, stdoutRedirName, stdoutRedirNameLength);
@@ -1802,7 +1802,7 @@ CreateProcess (FastOS_UNIX_Process *process,
         WriteInt(_mainSocket, 0);
 
     const char *stderrRedirName = process->GetStderrRedirName();
-    if (stderrRedirName != NULL) {
+    if (stderrRedirName != nullptr) {
         int stderrRedirNameLength = strlen(stderrRedirName) + 1;
         WriteInt(_mainSocket, stderrRedirNameLength);
         WriteBytes(_mainSocket, stderrRedirName, stderrRedirNameLength);
@@ -1866,7 +1866,7 @@ FastOS_UNIX_ProcessStarter::PollReapDirectChildren(void)
 
         FastOS_ProcessInterface *node;
         for(node = _app->GetProcessList();
-            node != NULL; node = node->_next)
+            node != nullptr; node = node->_next)
         {
             FastOS_UNIX_Process *xproc =
                 static_cast<FastOS_UNIX_Process *>(node);
@@ -1896,7 +1896,7 @@ FastOS_UNIX_ProcessStarter::PollReapProxiedChildren(void)
         ReadBytes(_mainSocket, &returnCode, sizeof(int));
 
         FastOS_ProcessInterface *node;
-        for(node = _app->GetProcessList(); node != NULL; node = node->_next)
+        for(node = _app->GetProcessList(); node != nullptr; node = node->_next)
         {
             FastOS_UNIX_Process *xproc =
                 static_cast<FastOS_UNIX_Process *>(node);
@@ -1922,7 +1922,7 @@ FastOS_UNIX_ProcessStarter::Wait(FastOS_UNIX_Process *process,
     FastOS_Time startTime;
     startTime.SetNow();
 
-    if (pollStillRunning != NULL)
+    if (pollStillRunning != nullptr)
         *pollStillRunning = true;
 
     for (;;) {
@@ -1935,7 +1935,7 @@ FastOS_UNIX_ProcessStarter::Wait(FastOS_UNIX_Process *process,
         process->_app->ProcessUnlock();
 
         if (process->GetDeathFlag()) {
-            if (pollStillRunning != NULL)
+            if (pollStillRunning != nullptr)
                 *pollStillRunning = false;
             break;
         }
@@ -1943,7 +1943,7 @@ FastOS_UNIX_ProcessStarter::Wait(FastOS_UNIX_Process *process,
         //      printf("wasn't dead yet (%d), sleeping\n",
         //             process->GetProcessId());
 
-        if (pollStillRunning != NULL)
+        if (pollStillRunning != nullptr)
             break;
 
         if ((timeOutSeconds != -1) && !timeOutKillAttempted) {
@@ -2032,9 +2032,9 @@ FastOS_UNIX_Process::DescriptorHandle::CloseHandle()
         close(_fd);
         _fd = -1;
     }
-    if (_readBuffer.get() != NULL)
+    if (_readBuffer.get() != nullptr)
         _readBuffer->Close();
-    if (_writeBuffer.get() != NULL)
+    if (_writeBuffer.get() != nullptr)
         _writeBuffer->Close();
 }
 void
diff --git a/fastos/src/vespa/fastos/unix_process.h b/fastos/src/vespa/fastos/unix_process.h
index ff034b0e581..16614deb1a2 100644
--- a/fastos/src/vespa/fastos/unix_process.h
+++ b/fastos/src/vespa/fastos/unix_process.h
@@ -86,32 +86,32 @@ public:
         else if(type == TYPE_STDERR)
             return _stderrListener;
 
-        return NULL;
+        return nullptr;
     }
 
     void CloseListener (DescriptorType type)
     {
         if(type == TYPE_STDOUT)
         {
-            if(_stdoutListener != NULL)
+            if(_stdoutListener != nullptr)
             {
-                _stdoutListener->OnReceiveData(NULL, 0);
-                _stdoutListener = NULL;
+                _stdoutListener->OnReceiveData(nullptr, 0);
+                _stdoutListener = nullptr;
             }
         }
         else if(type == TYPE_STDERR)
         {
-            if(_stderrListener != NULL)
+            if(_stderrListener != nullptr)
             {
-                _stderrListener->OnReceiveData(NULL, 0);
-                _stderrListener = NULL;
+                _stderrListener->OnReceiveData(nullptr, 0);
+                _stderrListener = nullptr;
             }
         }
     }
 
     FastOS_UNIX_Process (const char *cmdLine, bool pipeStdin = false,
-                         FastOS_ProcessRedirectListener *stdoutListener = NULL,
-                         FastOS_ProcessRedirectListener *stderrListener = NULL,
+                         FastOS_ProcessRedirectListener *stdoutListener = nullptr,
+                         FastOS_ProcessRedirectListener *stderrListener = nullptr,
                          int bufferSize = 65535);
     ~FastOS_UNIX_Process ();
     bool CreateInternal (bool useShell);
diff --git a/fastos/src/vespa/fastos/unix_socket.cpp b/fastos/src/vespa/fastos/unix_socket.cpp
index 2bdda49c982..ba1d2f50417 100644
--- a/fastos/src/vespa/fastos/unix_socket.cpp
+++ b/fastos/src/vespa/fastos/unix_socket.cpp
@@ -29,7 +29,7 @@ bool FastOS_UNIX_Socket::Shutdown()
     bool rc=true;
 
     if (ValidHandle()) {
-        if(_socketEvent != NULL) {
+        if(_socketEvent != nullptr) {
             EnableWriteEvent(false);
         }
         rc = (0 == shutdown(_socketHandle, SHUT_WR));
@@ -43,7 +43,7 @@ bool FastOS_UNIX_Socket::SetSoBlocking (bool blockingEnabled)
     bool rc=false;
 
     if (CreateIfNoSocketYet()) {
-        int flags = fcntl(_socketHandle, F_GETFL, NULL);
+        int flags = fcntl(_socketHandle, F_GETFL, nullptr);
 
         if (flags >= 0) {
             if (blockingEnabled) {
diff --git a/fastos/src/vespa/fastos/unix_thread.cpp b/fastos/src/vespa/fastos/unix_thread.cpp
index eca7a472c6d..8ff1913b246 100644
--- a/fastos/src/vespa/fastos/unix_thread.cpp
+++ b/fastos/src/vespa/fastos/unix_thread.cpp
@@ -11,11 +11,11 @@ namespace {
 
 bool FastOS_UNIX_Thread::InitializeClass ()
 {
-    if (getenv("VESPA_PIN_THREAD_TO_CORE") != NULL) {
+    if (getenv("VESPA_PIN_THREAD_TO_CORE") != nullptr) {
         _G_maxNumCpus = std::thread::hardware_concurrency();
         fprintf(stderr, "Will pin threads to CPU. Using %ld cores\n", _G_maxNumCpus);
-        if (getenv("VESPA_MAX_CORES") != NULL) {
-            size_t maxCores = strtoul(getenv("VESPA_MAX_CORES"), NULL, 0);
+        if (getenv("VESPA_MAX_CORES") != nullptr) {
+            size_t maxCores = strtoul(getenv("VESPA_MAX_CORES"), nullptr, 0);
             fprintf(stderr, "Will limit to %ld", maxCores);
             if (maxCores < _G_maxNumCpus) {
                 _G_maxNumCpus = maxCores;
@@ -76,7 +76,7 @@ FastOS_UNIX_Thread::~FastOS_UNIX_Thread()
 
     // Wait for thread library cleanup to complete.
     if (_handleValid) {
-        value = NULL;
+        value = nullptr;
         pthread_join(_handle, &value);
     }
 }
diff --git a/fastos/src/vespa/fastos/unix_time.cpp b/fastos/src/vespa/fastos/unix_time.cpp
index 4b83dcd60f5..c6251f60d03 100644
--- a/fastos/src/vespa/fastos/unix_time.cpp
+++ b/fastos/src/vespa/fastos/unix_time.cpp
@@ -99,6 +99,6 @@ FastOS_UNIX_Time::SetSecs(double secs)
 }
 
 void FastOS_UNIX_Time::SetNow() {
-    gettimeofday(&_time, NULL);
+    gettimeofday(&_time, nullptr);
 }