Unable to check Null condition in a Shell Script

Question

Hi,
When I am using to check the Null Condition To check for a Running Java Process its failing to check.
I am using variable in a shell script
DPID=$(ps -ef |grep - i java|grep -v grep)
if [ "$DPID"="" ' ];then
else
fi
If the DPID has Null value then its getting executed but if the DPID has value its not getting into the else part of the loop
Thanks and Regards

Answer 1

You could try -c to make grep return a count of matches, then check if this count is zero or not.
DPID=`ps -ef |grep - i java|grep -vc grep`
if [[ $DBID -ne 0 ]]; then
else
fi