Dgzt

version: "3.8"

services:
  maildev:
    image: maildev/maildev:1.1.0
    restart: always
    ports:
      - "1080:80"
      - "1025:25"

Dgzt

#!/bin/bash

if [[ "$1" ]]; then
    num="$1"
else
    num="1"
fi

if [[ ! $num == ?(-)+([0-9]) ]]; then
    echo "The given value is not integer!" >&2; exit 1