Re: umatched pattern in case-statement, why?

[Greg Wooledge]

On Mon, Sep 02, 2024 at 17:11:46 +0000, shynur . wrote:
> Hi, friends~
> 
> I'm writing some Bash code and having some trouble...
> 
>     d=[[:digit:]] d3=$d$d$d d4=$d3$d
>     line='(001) 345-0000'
>     case $line in
>         "($d3) $d3-$d4")
>             echo $line;;
>     esac
> 
> Why doesn't the above code print anything?  TIA.

The pattern is enclosed in double quotes, so all of the special characters
in it lose their special meanings.

Compare:

hobbit:~$ case a in "?") echo yes;; esac
hobbit:~$ case a in ?) echo yes;; esac
yes
hobbit:~$ 

Your best bet is to create yet another variable containing the entire
pattern you want to match, and use that (without quotes) as the label:

    d='[[:digit:]]'
    pattern="($d$d$d) $d$d$d-$d$d$d$d"
    line='(001) 345-0000'
    case $line in $pattern) echo yes;; esac