Bash Case 菜单 - 动态选择
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Bash Case menu - dynamic choices
提问by Chasester
I'm not sure what the policy is here on asking followup questions. So please excuse me if i'm breaking protocol. Earlier I was constructing a menu in bash ( Here)
我不确定这里关于询问后续问题的政策是什么。如果我违反了协议，请原谅。早些时候我在 bash 中构建了一个菜单（这里）
And so far I've got it working really good. Code here.
到目前为止，我已经让它工作得非常好。代码在这里。
while [[ 1 ]]
do
cat -n "$dumpfile"
read -p "Please make a selection, select q to quit: " choice
case $choice in
# Check for digits
[0-9] ) dtvariable=$(sed -n "$choice"p "$dumpfile")
$dtvariable ;;
q|Q)
break
;;
*)
echo "Invalid choice"
;;
esac
done
Except - that works great for menu items up to 9. The menu will be dynamic - could have 1 item, 20 items, or 197 items. I've tried changing [0-9] to be [0-9][0-9] to see if it would take 12. But it doesn't. Can anyone put me on the right path? I suppose I could just remove the [0-9] part and take anything that is not q. But wouldn't it be better to look for numbers?
除了 - 这对于最多 9 个菜单项非常有用。菜单将是动态的 - 可以有 1 个项目、20 个项目或 197 个项目。我已经尝试将 [0-9] 更改为 [0-9][0-9] 以查看是否需要 12。但事实并非如此。谁能让我走上正确的道路？我想我可以删除 [0-9] 部分并取任何不是 q 的东西。但是寻找数字不是更好吗？
Thank you in advance.
先感谢您。
采纳答案by Paused until further notice.
I would do some validation on $choice:
我会做一些验证$choice：
case $choice in
# Check for digits
+([0-9]))
lines=($(wc -l ))
if (( choice > 0 && choice <= lines ))
then
dtvariable=$(sed -n "$choice"p "$dumpfile")
$dtvariable ;;
fi
# etc.
回答by Jim Garrison
Here's what I got to work. The primary differences are the addition of shopt -s extglob, which turns on extended pattern matching, and the +([0-9])pattern, which
is the bash equivalent of regular expression [0-9]+
这就是我的工作。主要区别是添加了shopt -s extglob，它打开扩展模式匹配，以及+([0-9])模式，它是正则表达式的 bash 等价物[0-9]+
shopt -s extglob
while [[ 1 ]]
do
read -p "Please make a selection, select q to quit: " choice
case $choice in
# Check for digits
+([0-9]))
echo $choice ;;
q|Q)
break
;;
*)
echo "Invalid choice"
;;
esac
done
