diff --git a/src/libCom/osi/epicsThread.cpp b/src/libCom/osi/epicsThread.cpp
index 2d26edde7..d1c965e5b 100644
--- a/src/libCom/osi/epicsThread.cpp
+++ b/src/libCom/osi/epicsThread.cpp
@@ -240,4 +240,13 @@ const char *epicsThread::getNameSelf ()
     return epicsThreadGetNameSelf ();
 }
 
+bool epicsThread::isShellContext () const
+{
+    return static_cast<int>(epicsThreadIsShellContext(this->id));
+}
+
+void epicsThread::setShellContext(bool isShell)
+{
+    epicsThreadSetShellContext(this->id,static_cast<int>(isShell));
+}
 
diff --git a/src/libCom/osi/epicsThread.h b/src/libCom/osi/epicsThread.h
index f5975a7c4..1301c117c 100644
--- a/src/libCom/osi/epicsThread.h
+++ b/src/libCom/osi/epicsThread.h
@@ -97,6 +97,10 @@ epicsShareFunc const char * epicsShareAPI epicsThreadGetNameSelf(void);
 epicsShareFunc void epicsShareAPI epicsThreadGetName(
     epicsThreadId id, char *name, size_t size);
 
+epicsShareFunc int epicsShareAPI epicsThreadIsShellContext(epicsThreadId id);
+epicsShareFunc void epicsShareAPI epicsThreadSetShellContext(
+     epicsThreadId id,int isShell);
+
 epicsShareFunc void epicsShareAPI epicsThreadShowAll(unsigned int level);
 epicsShareFunc void epicsShareAPI epicsThreadShow(
     epicsThreadId id,unsigned int level);
@@ -151,6 +155,8 @@ public:
     static void sleep (double seconds);
     /* static epicsThread & getSelf (); */
     static const char * getNameSelf ();
+    bool isShellContext () const;
+    void setShellContext(bool isShell) ;
     class mustBeCalledByManagedThread {}; /* exception */
 private:
     epicsThreadRunable & runable;
diff --git a/src/libCom/osi/os/RTEMS/osdThread.c b/src/libCom/osi/os/RTEMS/osdThread.c
index 7f0264f4a..da7b9ff0f 100644
--- a/src/libCom/osi/os/RTEMS/osdThread.c
+++ b/src/libCom/osi/os/RTEMS/osdThread.c
@@ -48,6 +48,7 @@ struct taskVar {
     void                *parm;
     unsigned int        threadVariableCapacity;
     void                **threadVariables;
+    int              isShell;
 };
 static epicsMutexId taskVarMutex;
 static struct taskVar *taskVarHead;
@@ -213,6 +214,7 @@ setThreadInfo (rtems_id tid, const char *name, EPICSTHREADFUNC funptr,void *parm
     v->parm = parm;
     v->threadVariableCapacity = 0;
     v->threadVariables = NULL;
+    v->isShell = 0;
     note = (rtems_unsigned32)v;
     rtems_task_set_note (tid, RTEMS_NOTEPAD_TASKVAR, note);
     taskVarLock ();
@@ -452,6 +454,28 @@ epicsThreadId epicsThreadGetId (const char *name)
     return (epicsThreadId)tid;
 }
 
+int epicsThreadIsShellContext (epicsThreadPrivateId id)
+{
+    unsigned int varIndex = (unsigned int)id;
+    rtems_unsigned32 note;
+    struct taskVar *v;
+
+    rtems_task_get_note (RTEMS_SELF, RTEMS_NOTEPAD_TASKVAR, &note);
+    v = (struct taskVar *)note;
+    return v->isShell;
+}
+
+void epicsThreadSetShellContext (epicsThreadPrivateId id,int isShell)
+{
+    unsigned int varIndex = (unsigned int)id;
+    rtems_unsigned32 note;
+    struct taskVar *v;
+
+    rtems_task_get_note (RTEMS_SELF, RTEMS_NOTEPAD_TASKVAR, &note);
+    v = (struct taskVar *)note;
+    v->isShell = isShell;
+}
+
 /*
  * Ensure func() is run only once.
  */
diff --git a/src/libCom/osi/os/WIN32/osdThread.c b/src/libCom/osi/os/WIN32/osdThread.c
index edea368b0..c6734b1ec 100644
--- a/src/libCom/osi/os/WIN32/osdThread.c
+++ b/src/libCom/osi/os/WIN32/osdThread.c
@@ -52,6 +52,7 @@ typedef struct win32ThreadParam {
     DWORD id;
     unsigned epicsPriority;
     char isSuspended;
+    int isShell;
 } win32ThreadParam;
 
 typedef struct epicsThreadPrivateOSD {
@@ -844,6 +845,27 @@ epicsShareFunc void epicsShareAPI epicsThreadGetName (
     }
 }
 
+/*
+ * epicsThreadIsShellContext () 
+ */
+epicsShareFunc int epicsShareAPI epicsThreadIsShellContext ( epicsThreadId id ) 
+{
+    win32ThreadParam *pParm = ( win32ThreadParam * ) id;
+
+    return pParm->isShell;
+}
+
+/*
+ * epicsThreadSetShellContext () 
+ */
+epicsShareFunc int epicsShareAPI epicsThreadSetShellContext (
+      epicsThreadId id, int isShell) 
+{
+    win32ThreadParam *pParm = ( win32ThreadParam * ) id;
+
+    pParm->isShell = isShell;
+}
+
 /*
  * epics_GetThreadPriorityAsString ()
  */
diff --git a/src/libCom/osi/os/posix/osdThread.c b/src/libCom/osi/os/posix/osdThread.c
index 543249a80..c8c57b15e 100644
--- a/src/libCom/osi/os/posix/osdThread.c
+++ b/src/libCom/osi/os/posix/osdThread.c
@@ -55,6 +55,7 @@ typedef struct epicsThreadOSD {
     int                isSuspended;
     unsigned int       osiPriority;
     char              *name;
+    int               isShell;
 } epicsThreadOSD;
 
 static pthread_key_t getpthreadInfo;
@@ -582,6 +583,18 @@ const char *epicsThreadGetNameSelf()
     return(pthreadInfo->name);
 }
 
+int epicsThreadIsShellContext(epicsThreadId pthreadInfo) {
+    assert(epicsThreadOnceCalled);
+    assert(pthreadInfo);
+    return pthreadInfo->isShell;
+}
+
+void epicsThreadSetShellContext(epicsThreadId pthreadInfo,int isShell) {
+    assert(epicsThreadOnceCalled);
+    assert(pthreadInfo);
+    pthreadInfo->isShell = isShell;
+}
+
 void epicsThreadGetName(epicsThreadId pthreadInfo, char *name, size_t size)
 {
     assert(epicsThreadOnceCalled);
diff --git a/src/libCom/osi/os/vxWorks/osdThread.c b/src/libCom/osi/os/vxWorks/osdThread.c
index 583077269..3f5d734d7 100644
--- a/src/libCom/osi/os/vxWorks/osdThread.c
+++ b/src/libCom/osi/os/vxWorks/osdThread.c
@@ -40,6 +40,9 @@
 static const unsigned stackSizeTable[epicsThreadStackBig+1] = 
    {4000*ARCH_STACK_FACTOR, 6000*ARCH_STACK_FACTOR, 11000*ARCH_STACK_FACTOR};
 
+/*tasVar for isShell*/
+int isShell;
+
 /* definitions for implementation of epicsThreadPrivate */
 static void **papTSD = 0;
 static int nepicsThreadPrivate = 0;
@@ -125,6 +128,7 @@ static void createFunction(EPICSTHREADFUNC func, void *parm)
     (*func)(parm);
     free(papTSD);
     taskVarDelete(tid,(int *)&papTSD);
+    taskVarDelete(tid,&isShell);
 }
 
 epicsThreadId epicsThreadCreate(const char *name,
@@ -145,6 +149,8 @@ epicsThreadId epicsThreadCreate(const char *name,
         errlogPrintf("epicsThreadCreate taskSpawn failure for %s\n",name);
         return(0);
     }
+    taskVarAdd(tid,&isShell);
+    taskVarSet(tid,&isShell,0);
     return((epicsThreadId)tid);
 }
 
@@ -270,6 +276,16 @@ void epicsThreadGetName (epicsThreadId id, char *name, size_t size)
     name[size-1] = '\0';
 }
 
+int epicsThreadIsShellContext(epicsThreadId id)
+{
+    return isShell;
+}
+
+void epicsThreadSetShellContext(epicsThreadId id,int yesNo)
+{
+    isShell = yesNo;
+}
+
 void epicsThreadShowAll(unsigned int level)
 {
     taskShow(0,2);