postgres database hand tool backup with bash script (pg_dump package is required)

postgres_backup_bash_script.sh

#/user/bin/sh

systemUser=$(whoami)
date=$(date +'%m-%d-%Y')

echo "postgress database hand tool runed by ${systemUser} at ${date}."

path="./db/backup"

echo "Enter Database Host (localhost):"
read host
echo "Enter Database post (5432):"
read port
echo "Enter Database user (postgres):"
read user
echo "Enter Database name:"
read dbName

if [ -z "$host" ]
then
      host="localhost"
fi

if [ -z "$port" ]
then
      port="5432"
fi

if [ -z "$user" ]
then
      user="postgres"      
fi

if [ -z "$dbName" ]
then
      echo "ERROR> Database Name is required"
      exit 125
else
     filename="${date}_from_${dbName}_by_${systemUser}.sql"
     echo "Start backuping database ${filename} in ${path}..."
fi

{
    pg_dump -h $host -p $port -U $user -W -d $dbName > "${path}/${filename}"
    echo "DONE."
} || { 
    echo "ERROR> An unexpected error happend!"
    exit 125
}