Alternative for `sleep seconds` that takes system load into account?

Question

So I develop my server app and some client apps for it. After each rebuild I start my server (which tends to load qup all services for something like 2 seconds) and then I start my clients... So his is what I have in my script:

cd $RUN_DIR
nohup ./CloudServer >& /dev/null &
sleep 5
nohup ./CloudClient --server=localhost --username=$ROBOT1_NAME --robot >& /dev/null &
nohup ./CloudClient --server=localhost --username=$ROBOT2_NAME --robot >& /dev/null &

I wonder are there any alternatives for sleep in Bash? Like wait at least 5 seconds and then until CPU activety on process X will go down to 1% and then launch what I need?

Answer 1

You may need to change some things like the grep criteria and the CPU threshold but here it goes:

#!/bin/bash
cd $RUN_DIR
nohup ./CloudServer >& /dev/null &
PID=`ps aux |grep $RUN_DIR/CloudServer|grep -v grep| head -n 1 |awk '{print $2}'`

while [ `top -n 1 -b -p $PID | grep $PID |awk '{print $9"/1"}' |bc` -gt 1 ]
do
        sleep 2
        echo Server still starting up ...
done
echo Server is now Idle
nohup ./CloudClient --server=localhost --username=$ROBOT1_NAME --robot >& /dev/null &
nohup ./CloudClient --server=localhost --username=$ROBOT2_NAME --robot >& /dev/null &

You may change the sleep time, if you wish, too.