Shell Programming and Scripting

Hello ,
Im not from any school , im just learing unix and this an excercise problem from a book, which i was trying for a long time and was unable to get a answer and thought of posting so i may get a solution.

Try incorporating the following also in madmat's script.

kill -STOP pid suspend the process and swap it out
kill -CONT pid resume a process previously stopped

You need to get the pid of the new script.

In short, it should be like this.

Code:

Run the new-script.
Get the pid of the new-script.
kill -STOP on pid
sleep for n seconds.
kill -CONT pid

Vino

Hello Vino,
Thanks for the reply,
i have tried the madmat code , but the code runs the script i pass as argument and then sleep , but i want the script to run for second argument seconds and then sleep for second argument seconds and continue till 1st arument script executes and i have been trying in this way

#! /bin/bash

$1 & # run it in background
pid=$! # note it's process ID

i=1 # first state is 1=running
while :; do # endless loop
sleep $2 # wait
ps $pid > /dev/null || break # if no process, the exit loop
test $i -eq 1 \ # if current state is 1=running...
&& kill -SIGSTOP $pid \ #... then stop it...
|| kill -SIGCONT $pid #... else continue
((i=1-i)) # change the state between 1 and 0
done

Can u plz help me
Thanks in advance

Can any plz help

Check this out.

Code:

#! /bin/ksh

if [[ $# -ne 2 ]] ; then
echo "Need just 2 arguments"
exit 1;
fi ;

SCRIPT=${1}
TIME=${2}

echo "$SCRIPT will run for $TIME sec"

$SCRIPT &
pid=$!

while kill -0 $pid 2> /dev/null
do
        kill -s CONT $pid         
        #skill -s CONT -p $pid
        sleep $TIME

        kill -s STOP $pid 2> /dev/null
        #skill -s STOP -p $pid
        sleep $TIME
done ;

Not tested tho'.

If kill -s STOP $pid 2> /dev/null doesnt work then try skill -s STOP -p $pid. and likewise for kill -s CONT


Vino

warangalboy, please read our rules. And in particular:
(4) Do not 'bump up' questions if they are not answered promptly. No duplicate or cross-posting and do not report a post where your goal is to get an answer more quickly.

Both your duplicate thread and your "Can any plz help" post are against that rule. If this is just a problem from some book and not a classwork assignment, can you help me understand the urgency? What would be your idea of a low priority problem?

vino, the "kill -0 $pid" idea is great. That's a much better way to check if the process is still running. But if those kill commands don't work, the skill commands won't help either. Anyway skill won't be on most unix boxes. I have only seen it on Linux.

Complex signals like this do not mix well with many shell scripts. The problem is that shell scripts are a collection of processes, not the single process that you are signalling.