我需要编写一个bash脚本,它接收一个数组(N个以空格分隔的整数)作为命令行参数,并输出整数之和。
当我传递一个字符串作为参数时,我从expr
得到一个错误,而我的程序应该写一个以Usage:
开头的错误信息,如下所述。
bash : test.sh hello world
expr: non-integer argument
实施如下:
#!/bin/bash
for i do
sum=$(expr $sum + $i)
done
echo $sum
预期规格如下:
$ bash my-script.sh 1 2 3 4
10
$ bash my-script.sh
Usage:- bash my-script.sh space-separated-integers
$ bash my-script.sh hello world
Usage:- bash my-script.sh space-separated-integers
#!/usr/bin/env bash
# No arguments
if [[ $# -eq 0 ]]; then
echo "Usage:- bash $0 space-separated-integers" >&2
exit 1
fi
result=0
reg='^[0-9]+$'
# One argument is not a number
for arg in "$@"; do
if ! [[ $arg =~ $reg ]] ; then
echo "Usage:- bash $0 space-separated-integers" >&2
exit 1
else
((result += arg))
fi
done
echo "$result"