Linux bash 定时器

Question

好的，这里是愚蠢的新手问题。我以为我在制作倒数计时器。这应该是从 5 开始倒计时，一旦倒数到 0，则执行 echo“time is up clown”然后结束。我在这里做错了什么？

seconds=5
date1=$((`date +%s` + $seconds)); 
while [ "$date1" -ne `date +%s` ]; do 
  if (!$date1 -lt ((`date +%s` + $seconds)+1)); then
     echo "time is up clown";
  break;
  fi;
  echo -ne "$(date -u --date @$(($date1 - `date +%s` )) +%H:%M:%S)\r";
done

Answer 1

#!/bin/bash
SECS=5
while [[ 0 -ne $SECS ]]; do
    echo "$SECS.."
    sleep 1
    SECS=$[$SECS-1]
done
echo "Time is up, clown."