Linux - Expect script hangs

Hi,
I have script which is based on TCL and expect. It is written to test my code. It usually runs fine for a while and hangs after sometime.


Code snippet

set l_temp_timeout $timeout
OUTPUT_LOG2 2 >>>$expect_out(buffer)<<<
OUTPUT_LOG2 2 "Expecting...$my_prompt"
set timeout 3

expect {
$my_prompt { set l 1 }
timeout { OUTPUT_LOG2 2 $expect_out(buffer) }
}
OUTPUT_LOG2 2 "...Out of Expect $my_prompt"



My log for this code normally looks like

Retrying...
>>>^M^M
238114.0^M
^Mswitch(config-if-hsrp)#<<<
Expecting...#
...Out of Expect #



But once this hangs it looks like


Retrying...
>>>^M^M
704802.0^M
^Mswitch(config-if-hsrp)#<<<
Expecting...#


Screen shot for this

^Mswitch(config-if-hsrp)# echo 704802.0^M
704802.0
^Mswitch(config-if-hsrp)# sh ip route vrf all^M
sh ip route vrf all

IP Route Table for VRF "default"
:
:
:
:
IP Route Table for VRF "cisco3"
'*' denotes best ucast next-hop '**' denotes best mcast next-hop
'[x/y]' denotes [preference/metric]

0.0.0.0/32, 1 ucast next-hops, 0 mcast next-hops
*via Null0, [220/0], 00:25:03, local, discard
255.255.255.255/32, 1 ucast next-hops, 0 mcast next-hops
*via sup-eth1, [0/0], 00:25:03, local



Even I noticed that the prompt did not come back. Not sure whats the problem. Even if the prompt which is "#" did not show up, at least it should have timed out.

Why is it hanging ?


Thanks
Naveen