usage: wait.sh 30 google.com:80 yahoo.com:80

Compose wait-for-it

#!/bin/bash
#   Use this script to test if a given TCP host/port are available
cmdname=$(basename $0)
timeout=30
if [[ $1 =~ ^[0-9]+$ ]]; then
  timeout=$1
  shift 1
fi

while [[ $# -gt 0 ]]; do 
    case "$1" in
        *:* )
          address=$1
          address=${address##http://}
          address=${address##https://}
          address=${address%%/*}
          hostport=(${address//:/ })
          HOST=${hostport[0]}
          PORT=${hostport[1]}
          
          echo "Waiting $timeout seconds on $HOST:$PORT..." 
          timeout $timeout nc -z $HOST $PORT
          if [[ $? -ne 124 ]]; then
            echo "Connected to ${HOST}"
          else
            echo "Connection refused ${HOST}"
            exit 1
          fi
          shift 1
        ;;
        *)
          echo "Argument: \"$1\" has no HOST:PORT format."
          exit 1
        ;;
    esac
done