Shell Programming and Scripting

In my script i am writing to a counter file the no of processes i had started,
that is each time i start a process, i will increment the content of counter file and also when the process ends i will decrement the content of the file.

after this i do some other activities, by now i want to decide to execute further or wait till the processes i started earlier got over.

So i keep reading the counter file for till content becoming zero.
I am confused of writing the above part in script please help me writing a loop to keep reading the file till the contents become zero.

regards,
Senthil

Since you didn't post your OS/version or even the shell you are using OR any of the script - one can only guess that this thread will help.
Specifically:

Code:

while [ $(( THREAD_CNT - 1 )) -gt 0 ]
            do
                update_process_status \
                     ${RUN_ID:-0} \
                     ${P_FN_CD} \
                     "InProgress" \
                     "staging ${FILE_TYPE} - sqlldr - threads still running: $(( THREAD_CNT - 1))" \
                     0
                sleep 2
                THREAD_CNT=$(ps -p $(print ${PID_LIST} | tr -d ' ' | nawk '{print substr($0,1,length($0)-1)}') | wc -l)
            done