#!/usr/bin/env bash [[ -z $1 || ! $1 =~ ^[0-9]+$ ]] && echo "Usage: $0 " && exit 1 [[ $(( $1%7 )) = 0 ]] && res+="Pling" [[ $(( $1%5 )) = 0 ]] && res+="Plang" [[ $(( $1%3 )) = 0 ]] && res+="Plong" [[ -z $res ]] && res=$1 echo $res