waiting for an oracle database to become available

wait-port.sh

#!/bin/sh -eu
# Wait for port to get available

LOOPS="1000"
PORT=$1

i=0
while ! nc localhost $PORT >/dev/null 2>&1 < /dev/null; do
  i=`expr $i + 1`
  if [ $i -ge $LOOPS ]; then
    echo "$(date) - :${PORT} still not reachable, giving up"
    exit 1
  fi
  echo "$(date) - waiting for :${PORT}..."
  sleep 1
done

export ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe
export PATH=$ORACLE_HOME/bin:$PATH
export ORACLE_SID=XE

sqlplus -s /nolog <<EOF
connect system/oracle
select CURRENT_TIMESTAMP from DUAL;
quit
EOF

echo "$(date) - port ${PORT} open"

tail -f /dev/null