Shell Programming and Scripting

#!/bin/sh

echo "running" > /var/tmp/process-status.txt

## Insert the method to launch your java code here.
## e.g. $JAVA_HOME/bin/java -jar /path/to/jarfile.jar

echo "complete" > /var/tmp/process-status.txt

#!/bin/sh

COUNTER=0
# Do this 10 times. Keeps the process from running forever...
while [ $COUNTER -lt 11 ]; do
     if [ -f /var/tmp/process-status.txt ]; then

        # Nothing fancy, just snag the return code from grep.
        # send the output to /dev/null, because we don't really 
        # care about it.
        grep complete /var/tmp/process-status.txt &> /dev/null
    
        # if grep found complete, $? will be 0, otherwise 1.
        if [ $? -eq 0 ]; then
             # Insert the code to run your 2nd java app.
             # e.g. $JAVA_HOME/bin/java -jar /path/to/jar.file
          
              # remove the status file, so we don't get confused 
              # the next time we run.
              rm /var/tmp/process-status.txt
              
              # the break here will "break out" of the loop, regardless of the
              # status of the $COUNTER variable.
              break
        fi
    fi
    
    # the file either didn't exist, or the file doesn't have "complete" in it, so
    # we'll wait for 60 seconds and try again.
    sleep 60

    # increase our counter variable by 1.
    let COUNTER=COUNTER+1
done

if [ $COUNTER -eq "11" ]; then
   # Our counter variable got too big, which means that the 
   # loop would stopped. With the sleep in there, we waited 10 minutes 
   # for the earlier code to populate the file with "complete". We should
   # Probably generate an error of some type.
   #
   # If cron is setup properly, it'll email all output to root@localhost, so 
   # we'll just let cron handle notifying the operator.
   #
   echo "WARNING: $0 failed to run. Something is broken."
fi