Linux Shell 脚本计算1到N的和

#!/bin/bash//n//necho /'请输入一个小于50的正整数/'//nread n//n//nif [[ //$n -ge 50 || //$n -le 0 ]]; then//n echo /'输入有误/'//n exit 1//nfi//n//nsum=0//nfor (( i=1; i<=//$n; i++ )); do//n sum=$((sum+i))//ndone//n//necho /'1+2+..+//$n的和为: //$sum/