run process within script to continually check for status

[gotchausa]

Using ksh, how would I do the following within a script:

1. Check for existence of a file
2. If file exists, do some other tasks. At the same time as these tasks are being done, continually rpt step 1. As soon as step 1 detects that file does not exist, quit from script immediately. If and when all tasks are done and file still exists, remove it.

THx.

 

[butterfm]

Hi mpv,

I would do something along these lines.
The "Other tasks" that you need to do will go in there own shell script e.g.

---------------------------------------------------
#!/bin/ksh

Loops=0
while [ $Loops -lt 5 ]
do
sleep 10
Loops=`expr $Loops + 1`
TimeGone=`expr $Loops * 10`
echo "Time running is $TimeGone secs" >> ./Loops.out
done

rm -f ./blah.txt #remove file here after other stuff
#finishes
--------------------------------------------------------

The above script is executed in the background by a controlling loop that continually monitors whether the file is still there. As soon as it dissappears it will kill the above script (if it's still there and terminate)
e.g.

--------------------------------------------------------
#!/bin/ksh

if [ -f ./blah.txt ]
then
./test.sh & #start other script in background
Process=$! #capture PID

Flag=1

while [ $Flag -eq 1 ]
do
sleep 1
if [ ! -f ./blah.txt ]
then
#file's dissappeared
kill $Process > /dev/null
Flag=0 #exit loop
fi
done
fi

---------------------------------------------------------

Hope this is what you wanted.

MB.

 

[gotchausa]

Thanks a lot! Yes, this is along the line of what I need, I'll try it out and hope it works correctly...