learning shell commands

scp -r Copy directory, can copy remote directory, cp can only copy local directory
ssh root@host "" Remote script execution
-d If the directory exists, it is a true
linux function

qa(){
      host="192.168.199.2"
}

execute linux function
qa

case "$2" in
  product)
        product
        ;;
 qa)
     qa
     ;;
  *)
        echo $""
        exit 2
esac