shell script 运行出错。麻烦高手帮我看看

coolrise

  6 PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
  7 export PATH
  8
  9 echo "This program will try to calculate : "
10 echo "how many days before yr demobilization date..."
11 read -p "pls input yr dempbilization date (YYYYMMDD ex>20080401): " date2
12
13 date_d=$(echo $date2 | grep '[0-9]\{8\}')
14
15 if [ "$date_d" == "" ];then
16         echo "u input the worng date format"
17         exit 1
18 fi
19
20 declare -i date_dem='date --date="$date2" + %s'
21 declare -i date_now='date + %s'
22 declare -i date_total_s=$(($date_dem-$date_now))
23 declare -i date_d=$((date_total_s/60/60/24))
24
25 if [ "$date_total_s" -lt "0" ];then
26         echo "u had been demobilization before: "$((-a*$date_d))" ago"
27 else
28         declare -i date_h=$(($(($date_total_s-$date_d*60*60*24))/60/60))
29         echo "u will demobilize after $date_d days and $date_h hours."







=-======错误=====
sh11.sh: line 20: declare: date --date="$date2" + %s: syntax error in expression (error token is "date="$date2" + %s")
sh11.sh: line 21: declare: date + %s: syntax error: operand expected (error token is "%s")
sh11.sh: line 22: -: syntax error: operand expected (error token is "-")