Script to run a process

sorry to ask a script again,

I am not too understand shell script writing , could someone can help
me ,

I want to have a shell script for testing , the process will run
repeatly (looping), I want to test the CPU time , I have the below
script to test :

while x=0
do
cp /tmp/abc.txt /tmp/def.txt
done

the process is non-stop running , but it is not fit my requirement ,
because the above script will generate a new process after the old
process was completed , what I want is a SAME process is running
non-stop (same PID ) , could someone post a script for me ? thx in
advance.


I just want to have a script to run a process ( may be a looping ) ,
this process need to use the same PID . In my previous script , after
the cp process finished , it will generate another process ( so the
PID changed ) so not fit my requirement

could someone can post the script ? thx in advance.

script is as
-----------------------
lStart=1
lStop=10

while [ "$lStart" -le $lStop ]
do


sleep 100 #you can add this for time interval in each loop
done
-----------------------------