Question

I have a cron shell script which calls a stored procedure to do some operation. I want to know how can I change that cron to a daemon.

Here’s what I have.

    #!/bin/ksh
    # @(#)abc.sh    


    . /somedir/env/some_profile
    JOBNAME=`basename $0`
    LOG_DIR=$PROJHOME/log
    LOG_FILE=$LOG_DIR/process_abc.log

    function usage
    {
      echo "${JOBNAME}: Usage: ${JOBNAME}"
      echo "Exiting..."
      echo "process_abc ended ***UNSUCCESSFULLY*** at `date`" | tee -a $LOG_FILE
      echo ""  | tee -a $LOG_FILE
      exit 1
    }

Can you please help. Your help will be appreciated.

Thanks

Answer 1

you can just run it from bash

SLEEP_INTERVAL=3600
(echo $$ > /var/run/script-runner.sh.pid && while :; do script.sh ; sleep $SLEEP_INTERVAL ; done) &

or you can do the same loop inside the script

trap "function_that_runs_everything" HUP
echo $$ > /var/run/script.sh.pid
while :; do
    function_that_runs_everything
    sleep $SLEEP_INTERVAL #or sleep forever just waiting for SIGHUP
done

this way you can also force the execution of the internal function from the outside

kill -1 `cat /var/run/script.sh.pid`

also i would suggest rewriting:

if [ `/usr/ucb/ps -auxww | grep $JOBNAME | grep "sh -c" | grep -v grep  | wc -l` -gt 1 ]

to use $$ (current shell’s pid) and create pid file

pseudocode:
PIDFILE=/var/run/`basename $0`.pid
if $PIDFILE exists
    log and exit
else
    echo $$ > $PIDFILE

...
run
...
rm -f $PIDFILE

(dont forget to remove the pid file @ failure exits)