shell腳本之計算1-n的和

  1 #!/bin/bash                                                                 
  2 
  3 read -p "please input a number to compute the sum of 1-number:" number
  4 
  5 sum=0
  6 for i in `seq $number`
  7 do
  8     sum=$((sum+i))
  9     i=$((i+1))
 10 done
 11 echo "1+...+$number:$sum"