How to execute shell commands in a loop from within a bash script?

Question

I want to write a script which will run on my android phone & perform the following things:

echo "1" > /sys/kernel/mm/ksm/run

wait for 2 minutes: then

echo "0" > /sys/kernel/mm/ksm/run

then wait for 2-3hrs & loop over again.

Answer 1

You can use sleep with while loop as follows:

while true;
do
echo "1" > /sys/kernel/mm/ksm/run;
sleep 120;
echo "0" > /sys/kernel/mm/ksm/run;
sleep 7200;
done;

Here, while Loop starts with condition while true; that means no condition for stopping loop (it runs forever until script is killed) then commands will be run (with sleeping as you wish) at done; loop will be redirected to condition that is while true; thus, It will again start executing commands.

Note: with GNU sleep you can also use sleep 2m, sleep 2h etc.