Update example scripts to explicitly use python3.

Also update simple_agent to catch exceptions for invalid test calls.

Author: john

examples/run_callback_agent.sh

@@ -94,4 +94,4 @@ stty -echo
 
 # Now start the callback example agent
 echo "* Starting the callback example agent..."
-python callback_agent.py -m $TMPDIR/snmpd-agentx.sock -p $TMPDIR/
+python3 callback_agent.py -m $TMPDIR/snmpd-agentx.sock -p $TMPDIR/

examples/run_simple_agent.sh

@@ -94,4 +94,4 @@ stty -echo
 
 # Now start the simple example agent
 echo "* Starting the simple example agent..."
-python simple_agent.py -m $TMPDIR/snmpd-agentx.sock -p $TMPDIR/
+python3 simple_agent.py -m $TMPDIR/snmpd-agentx.sock -p $TMPDIR/

examples/run_simple_agent_trap.sh

@@ -160,7 +160,7 @@ echo ""
 
 # Now start the simple example agent
 echo "* Starting the simple example agent..."
-python simple_agent_trap.py -m $AGENTX_SOCK -p $TMPDIR/
+python3 simple_agent_trap.py -m $AGENTX_SOCK -p $TMPDIR/
 
 # Debug mode
 #gdb python -ex "run simple_agent_trap.py -m $AGENTX_SOCK -p $TMPDIR/"

examples/run_threading_agent.sh

@@ -92,4 +92,4 @@ stty -echo
 
 # Now start the threading agent
 echo "* Starting the threading agent..."
-python threading_agent.py -m $TMPDIR/snmpd-agentx.sock -p $TMPDIR/
+python3 threading_agent.py -m $TMPDIR/snmpd-agentx.sock -p $TMPDIR/

examples/run_threading_agent_trap.sh

@@ -38,7 +38,7 @@ do
 	fi
 done
 if [ -z "$SNMPTRAPD_BIN" ] ; then
-	echo "snmptrapd executable not found -- net-snmp not installed?"
+	echo "snmptrapd executable not found -- snmptrapd not installed?"
 	exit 1
 fi
 
@@ -160,7 +160,7 @@ stty -echo
 
 # Now start the threading agent
 echo "* Starting the threading agent..."
-python threading_agent_trap.py -m $AGENTX_SOCK -p $TMPDIR/
+python3 threading_agent_trap.py -m $AGENTX_SOCK -p $TMPDIR/
 
 # Debug mode
 # Remember to comment out 'stty -echo' few lines above

examples/simple_agent.py

@@ -273,6 +273,8 @@ def HupHandler(signum, frame):
 # handler above changes the "loop" variable.
 print("{0}: Serving SNMP requests, send SIGHUP to dump SNMP object state, press ^C to terminate...".format(prgname))
 
+table1Row1Cell3Val = 55
+
 loop = True
 while (loop):
 	# Block and process SNMP requests, if available
@@ -298,24 +300,42 @@ def HupHandler(signum, frame):
 	#
 	# As a workaround, Table.setRowColumn(row, col, data) was created to traverse rows from the table each time.
 	try:
+		# Incorrect indexing
 		firstTable.setRowColumn(1, 3, agent.Integer32(555))
 	except Exception as e:
 		print('Error from firstTable.setRowColumn: {:}'.format(e))
 
-	firstTable.setRowColumn(['aa'], 3, agent.Integer32(444))
+	# Valid indexing
+	firstTable.setRowColumn(['ab'], 2, agent.DisplayString('Gotham'))
+
 
-	# Another (better?) solution is to re-retrieve first row to mitigarte memory error
+	# Another (better?) solution is to re-retrieve first row to mitigate memory error
 	# Verify likely calling scenarios don't fail:
+	
+	# The following getRow() calls use incorrect indexing
 	try:
 		firstTableRow1 = firstTable.getRow(1)
 	except Exception as e:
 		print('Error from firstTable.getRow({:}): {:}'.format(1, e))
 
-	firstTableRow1 = firstTable.getRow(agent.DisplayString("aa"))
-	firstTableRow1 = firstTable.getRow([agent.DisplayString("aa")])
-	firstTableRow1 = firstTable.getRow(['aa'])
+	try:
+		firstTableRow1 = firstTable.getRow(agent.DisplayString("aa"))
+	except Exception as e:
+		print('Error from firstTable.getRow(agent.DisplayString("{:}")): {:}'.format("aa", e))
+
+	try:
+		firstTableRow1 = firstTable.getRow([agent.DisplayString("aa")])
+	except Exception as e:
+		print('Error from firstTable.getRow([agent.DisplayString("{:}")]): {:}'.format("aa", e))
+
+
+	table1Row1Cell3Val = table1Row1Cell3Val + 1
+# Valid Syntaxes:
 	firstTableRow1 = firstTable.getRow('aa')
-	firstTableRow1.setRowCell(3, agent.Integer32(77))
+	firstTableRow1 = firstTable.getRow(['aa'])
+	
+	firstTableRow1.setRowCell(3, agent.Integer32(table1Row1Cell3Val))
+
 
 	print('-------------- end of update --------------')