#!/bin/bash #program: #check how long you will demobilization form the army #histoyr: #2010/8/21 #!/bin/sh echo "this program will try to calculate" echo "how many days beforre your demobilization date ............." read -p "plseae input your demobilization date (YYYYYMMDD ex>20090401):" date2 date_d=$( echo $date2 | grep '[0-9]\{8\}') if [ "$date_d" == "" ]; then echo "you input the wrong date format" exit 1 fi declare -i date_dem=`date --date="$date2" +%s` declare -i date_now=`date +%s` declare -i date_total_s= $(($date_dem-$date_now)) declare -i date_d = $(($date_total_s/60/60/24)) if [ "$date_total_s" -lt "0" ]; then echo "you had been demobilization before: "((-1*$date_d))" ago" else declare -i date_h= $(( $(( $date_total_s - $date_d*60*60*24))/60/60)) echo "you will demobilize after $date_d days and $date_h hours" fi