Question

我正在尝试编写一个循环脚本，直到用户选择列表中的值（从0到9的单个数字）。这是我的.sh脚本，我尝试使用sh命令在ubuntu 16.04 shell中运行：

choice=999
echo $choice
until [[ $choice in 0 1 2 3 4 5 6 7 8 9 ]]
do
  read -p "How many would you like to add? " choice
done

无论我做什么，我都无法让它发挥作用。这是一个测试，让您了解手头的错误：

sh test2.sh
999
test2.sh: 3: test2.sh: [[: not found
How many would you like to add? f
test2.sh: 3: test2.sh: [[: not found
How many would you like to add? 2
test2.sh: 3: test2.sh: [[: not found
How many would you like to add? 3
test2.sh: 3: test2.sh: [[: not found
How many would you like to add? r
test2.sh: 3: test2.sh: [[: not found

我尝试了很多东西：

避免until并使用while
只使用单个方括号[ condition ]，或根本不使用括号
使用=~匹配正则表达式^[0-9]

没有任何作用。总是那个错误。这是怎么回事？：（

Answer 1

首先，您的sale_date , sales August , 6表明您没有使用Bash。在脚本顶部添加[[: not found，或使用#!/bin/bash运行，或使用标准bash test2.sh。

无论哪种方式，你都不能像那样使用[。一种替代方法是使用in语句：

case

关于while :; do read -p "How many would you like to add? " choice case $choice in [0-9]) break ;; esac done语句的好处是它们允许您使用glob模式，因此case匹配[0-9]到0之间的任何数字。

如果您计划最终使用Bash，您也可以选择以下内容：

此处，正则表达式用于匹配从#!/bin/bash until [[ $choice =~ ^[0-9]$ ]]; do read -p "How many would you like to add? " choice done到0的数字。

Answer 2

[[: not found是bash内置的，而不是sh。你可以检查一下你的砰砰声并确定它是#!/binb/bash，而不是#!/bin/sh吗？第二个，运行脚本为bash scriptname.sh，而不是sh。

最后，尝试重写你的脚本：

choice=999
echo $choice
while [[ "$(seq 0 9)" =~ "${choice}" ]]
do
  read -p "How many would you like to add? " choice
  # ((choice++)) If choice=999, script will not read anything. 
  # If 0 <= choice <= 9, script will not never stopped.
  # So, you should uncomment ((choice++)) to stop script running when choice become
  # more than 9.
done

循环直到列表中的选择

2 个答案: