Pinging server with payload from tclsh - windows

Question

I need to test how my remote server is handling ping request. I need to ping remote server from my windows with payload of say 50 kb. I need my tcl script sholud generate 20 such ping requests with 50 kb payload parallel so it will result 1 mb receive traffic at server at given instance. here is the code for ping test
proc ping-igp {} {
foreach i {
172.35.122.18
} {
if {[catch {exec ping $i -n 1 -l 10000} result]} {
set result 0
}
if {[regexp "Reply from $i" $result]} {
puts "$i pinged"
} else {
puts "$i Failed"
}
}
}

Answer 1

If you want to ping in parallel then you can use open instead of exec and use fileevents to read from the ping process.
An example of using open to ping a server with two parallel processes:
set server 172.35.122.18
proc pingResult {chan serv i} {
set reply [read $chan]
if {[eof $chan]} {
close $chan
}
if {[regexp "Reply from $serv" $result]} {
puts "$serv number $i pinged"
} else {
puts "$serv number $i Failed"
}
}
for {set x 0} {$x < 2} {incr $x} {
set chan [open "|ping $server -n 1 -l 10000"]
fileevent $chan readable "pingResult $chan {$server} $x"
}
See this page for more info: http://www.tcl.tk/man/tcl/tutorial/Tcl26.html

Answer 2

Here's a very simple piece of code to do the pinging in the background by opening a pipeline. To do that, make the first character of the “filename” to open be a |, when the rest of the “filename” is interpreted as a Tcl list of command line arguments, just as in exec:
proc doPing {host} {
# These are the right sort of arguments to ping for OSX.
set f [open "|ping -c 1 -t 5 $host"]
fconfigure $f -blocking 0
fileevent $f readable "doRead $host $f"
}
proc doRead {host f} {
global replies
if {[gets $f line] >= 0} {
if {[regexp "Reply from $host" $result]} {
# Switch to drain mode so this pipe will get cleaned up
fileevent $f readable "doDrain $f"
lappend replies($host) 1
incr replies(*)
}
} elseif {[eof $f]} {
# Pipe closed, search term not present
lappend replies($host) 0
incr replies(*)
close $f
}
}
# Just reads and forgets lines until EOF
proc doDrain {f} {
gets $f
if {[eof $f]} {close $f}
}
You'll also need to run the event loop; this might be trivial (you're using Tk) or might need to be explicit (vwait) but can't be integrated into the above. But you can use a clever trick to run the event loop for long enough to collect all the results:
set hosts 172.35.122.18
set replies(*)
foreach host $hosts {
for {set i 0} {$i < 20} {incr i} {
doPing $host
incr expectedCount
}
}
while {$replies(*) < $expectedCount} {
vwait replies(*)
}
Then, just look at the contents of the replies array to get a summary of what happened.