Segmentation fault in Ns2 program

Question

I have referred to a program of ns2 the program is giving me Segmentation fault(Core Dumped) when i changed this -> $ns at 0.5 “$cbr0 start” to this->$ns at 0.5 "$cbr0 start". Are the "" any problem .If i change "" to “” following is the error

ERRORS

(_o5 cmd line 1) invoked from within "_o5 cmd at 0.5 “_o84 start”" invoked from within "catch "$self cmd $args" ret" invoked from within "if [catch "$self cmd $args" ret] { set cls [$self info class] global errorInfo set savedInfo $errorInfo error "error when calling class $cls: $args" $..." (procedure "_o5" line 2) (SplitObject unknown line 2) invoked from within "_o5 at 0.5 “o84 start”" ("eval" body line 1) invoked from within "eval $scheduler at $args" (procedure "_o3" line 3) (Simulator at line 3) invoked from within "$ns at 0.5 “$cbr0 start”" (file "b.tcl" line 71)

CODE:

set ns [new Simulator]
#Define different colors for data flow 
$ns color 1 Blue
$ns color 2 Red

#open the nam trace file 
set nf [open out.nam w]
$ns namtrace-all $nf 

#define a finish procedure 
proc finish {} {
        global ns nf 
        $ns flush-trace 
        #close the trace file 
        close $nf 
        #execute nam on the trace file 
        exec nam out.nam&
        exit 0
        }

#create four nodes 
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]

#create links between nodes 
$ns duplex-link $n0 $n2 1Mb 10ms DropTail
$ns duplex-link $n1 $n2 1Mb 10ms DropTail
$ns duplex-link $n3 $n2 1Mb 10ms SFQ

#orientation

$ns duplex-link-op $n0 $n2 orient right-down
$ns duplex-link-op $n1 $n2 orient right-up
$ns duplex-link-op $n2 $n3 orient right

#Monitors the queue for the link betweeen node 2 & 3
$ns duplex-link-op $n2 $n3 queuePos 0.5

#Create udp agent and attatch it to node 0
set udp0 [new Agent/UDP]
$udp0 set class_ 1
$ns attach-agent $n0 $udp0

#Create CBR traffic source & attatch it to upd0 
set cbr0 [new Application/Traffic/CBR]
$cbr0 set packetSize_ 500
$cbr0 set interval_ 0.005
$cbr0 attach-agent $udp0

#Create udp agent and attatch it to node 1 
set udp1 [new Agent/UDP]
$udp1 set class_ 2
$ns attach-agent $n1 $udp1

#Create CBR traffic source & attatch it to upd1
set cbr1 [new Application/Traffic/CBR]
$cbr1 set packetSize_ 500
$cbr1 set interval_ 0.005
$cbr0 attach-agent $udp1

#Create a CBR traffic source & attatch it to udp 1 
set null0 [new Agent/Null]
$ns attach-agent $n3 $null0
#connect the traffic source with the traffic sink 
$ns connect $udp0 $null0
$ns connect $udp1 $null0

#Schedule events for the CBR agent 
$ns at 0.5 “$cbr0 start”
$ns at 1.0 “$cbr1 start”
$ns at 4.0 “$cbr1 stop”
$ns at 4.5 “$cbr0 stop”

#call finish after 5 seconds of simulation time 
$ns at 5.0 “finish”

#Run the simulator
$ns run

Knud Larsen Knud Larsen · Accepted Answer · 2017-10-10T19:40:10

“ ” are not legal characters in a Unix / Linux program. Must be " ".

A file that is similar to your file is "second.tcl" → udp-examples-2.tar.gz →
https://drive.google.com/file/d/0B7S255p3kFXNcDJOTWNUaFJrSkE/view?usp=sharing

'second.tcl' :

set ns [new Simulator]
#Define different colors for data flow 
$ns color 1 Blue
$ns color 2 Red

#open the nam trace file 
set nf [open out.nam w]
$ns namtrace-all $nf 

#define a finish procedure 
proc finish {} {
        global ns nf 
        $ns flush-trace 
        #close the trace file 
        close $nf 
        #execute nam on the trace file 
        exec nam out.nam&
        exit 0
        }

#create four nodes 
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]

#create links between nodes 
$ns duplex-link $n0 $n2 1Mb 10ms DropTail
$ns duplex-link $n1 $n2 1Mb 10ms DropTail
$ns duplex-link $n3 $n2 1Mb 10ms SFQ

#orientation

$ns duplex-link-op $n0 $n2 orient right-down
$ns duplex-link-op $n1 $n2 orient right-up
$ns duplex-link-op $n2 $n3 orient right

#Monitors the queue for the link betweeen node 2 & 3
$ns duplex-link-op $n2 $n3 queuePos 0.5

#Create udp agent and attatch it to node 0
set udp0 [new Agent/UDP]
$udp0 set class_ 1
$ns attach-agent $n0 $udp0

#Create CBR traffic source & attatch it to upd0 
set cbr0 [new Application/Traffic/CBR]
$cbr0 set packetSize_ 500
$cbr0 set interval_ 0.005
$cbr0 attach-agent $udp0

#Create udp agent and attatch it to node 1 
set udp1 [new Agent/UDP]
$udp1 set class_ 2
$ns attach-agent $n1 $udp1

#Create CBR traffic source & attatch it to upd1
set cbr1 [new Application/Traffic/CBR]
$cbr1 set packetSize_ 500
$cbr1 set interval_ 0.005
$cbr0 attach-agent $udp1

#Create a CBR traffic source & attatch it to udp 1 
set null0 [new Agent/Null]
$ns attach-agent $n3 $null0
#connect the traffic source with the traffic sink 
$ns connect $udp0 $null0
$ns connect $udp1 $null0

#Schedule events for the CBR agent 
$ns at 0.5 "$cbr0 start"
$ns at 1.0 "$cbr1 start"
$ns at 4.0 "$cbr1 stop"
$ns at 4.5 "$cbr0 stop"

#call finish after 5 seconds of simulation time 
$ns at 5.0 "finish"

#Run the simulator
$ns run

Works OK, the file first.nam 898kB is created, and the 'nam' window opens.

Link, all ~2500 examples https://drive.google.com/drive/folders/0B7S255p3kFXNSmRYb2lGcDRUdWs?usp=sharing

Segmentation fault in Ns2 program

1 Answers