Hi
I am new to this forum. Please forgive me, If I am wrong anywhere. I am trying to understand the below code. Can anyone help in understanding what is ${#ST} here. Is that the value of the first parameter??...what is exit 1 mean. Any clarification is greatly appreciated.

export ST=$1
export EN=$2
if [ ${#ST} -eq 0 ]
then
echo ${#ST}
echo ${ABORT} " START_STEP environment variable must be present"
echo "Process cannot be executed"
exit 1
fi
if [ ${#EN} -eq 0 ]
then
echo ${ABORT} " END_STEP environment variable must be present"
echo "Process cannot be executed"
exit 1
fi

Thank you,
Sudha