Added a maxBytesToPrint arg to snoopsharedmem

HISTORY.txt

@@ -15,6 +15,8 @@ key:  - new feature
      when possible.
    - Added IsAtStart() and IsAtEnd() convenience-methods to the
      HashtableIterator class.
+   - The snoopsharedmem tool now support an optional (maxBytesToPrint)
+     argument, in case you only want to see the header of the region.
    o Removed obsolete references to TARGET_PLATFORM_XENOMAI.
    o Updated the captive zlib library to the current GitHub version,
      to avoid "function declaration without a prototype is deprecated"

tools/snoopsharedmem.cpp

@@ -12,15 +12,26 @@ using namespace muscle;
 int main(int argc, char ** argv)
 {
    CompleteSetupSystem css;
+   uint32 maxBytesToPrint = MUSCLE_NO_LIMIT;
 
    if (argc < 2)
    {
-      LogTime(MUSCLE_LOG_CRITICALERROR, "Usage:  ./snoopsharedmem shared_memory_region_name\n");
+      LogTime(MUSCLE_LOG_CRITICALERROR, "Usage:  ./snoopsharedmem shared_memory_region_name [maxBytesToPrint]\n");
       return 0;
    }
 
    const char * shmemName = argv[1];
 
+   if (argc > 2)
+   {
+      const uint32 numBytes = atol(argv[2]);
+      if (numBytes > 0)
+      {
+         LogTime(MUSCLE_LOG_INFO, "Limiting printouts to the first " UINT32_FORMAT_SPEC " bytes of the shared memory area.\n", numBytes);
+         maxBytesToPrint = numBytes;
+      }
+   }
+
    status_t ret;
    SharedMemory m;
    if (m.SetArea(shmemName, 0, false).IsOK(ret))
@@ -32,7 +43,7 @@ int main(int argc, char ** argv)
       while(1)
       {
          (void) Snooze64(MillisToMicros(100));
-         PrintHexBytes(a, memSize);
+         PrintHexBytes(a, muscleMin(memSize, maxBytesToPrint));
       }
    }
    else LogTime(MUSCLE_LOG_ERROR, "SetArea(%s) failed, exiting! [%s]\n", shmemName, ret());