英文:
bash case variable not empty
问题
I'm using a case statement like this in one of my projects to check some combinations of variables:
fun(){
case "$a:$b:$c" in
*:*:*) echo fine;;
*:2:*) echo ok;;
3:*:*) echo good;;
*) echo not ok;;
esac
}
The goal of the first case *:*:*) is to check that one of the vars, lets say $c is not empty. But it's not working like that, it's basically the same as *) at the end and triggers false positive if $c is not set. I've tried to use *:*:+ and *:*:!' ' no luck. So I've ended up using this:
fun(){
c1=; [[ $c ]] && c1=1
case "$a:$b:$c1" in
*:*:1) echo fine;;
*:2:*) echo ok;;
3:*:*) echo good;;
*) echo not ok;;
esac
}
The question is - is there a better, more 'case' way?
英文:
I'm using a case statement like this in one of my projects to check some combinations of variables:
fun(){
case "$a:$b:$c" in
*:*:*) echo fine;;
*:2:*) echo ok;;
3:*:*) echo good;;
*) echo not ok;;
esac
}
The goal of the first case *:*:*) is to check that one of the vars, lets say $c is not empty. But it's not working like that, it's basically the same as *) at the end and triggers false positive if $c is not set. I've tried to use *:*:+ and *:*:!'' no luck. So I've ended up using this:
fun(){
c1=; [[ $c ]] && c1=1
case "$a:$b:$c1" in
*:*:1) echo fine;;
*:2:*) echo ok;;
3:*:*) echo good;;
*) echo not ok;;
esac
}
The question is - is there a better, more 'case' way?
答案1
得分: 1
你可以简单地使用?通配符，它匹配一个字符。与?*结合使用时，这将匹配至少一个字符。
case "$a:$b:$c" in
(*:*:?*) echo fine;;
(*:2:?*) echo ok;;
(3:*:?*) echo good;;
(*) echo not ok;;
esac
我认为你应该改变备选项的顺序，因为例如 3:2:1 将会匹配到 fine，而没有三元组会匹配到 ok 或 good。
英文:
You can simply use the ? glob, which matches exactly one character. In combination with ?* this matches at least one character.
case "$a:$b:$c" in
(*:*:?*) echo fine;;
(*:2:?*) echo ok;;
(3:*:?*) echo good;;
(*) echo not ok;;
esac
I think you should change the order of the alternatives, since e.g. 3:2:1 will be fine and no triplet will ever be ok or good.
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