Re: syntax error while parsing a case command within `$(...)'

[Eli Schwartz]

On 2/14/21 2:43 PM, Dale R. Worley wrote:
> Before we worry about what to change, I want to note that the original
> example is syntactically incorrect.  The example is
> 
>   $ bash -c ': $(case x in x) esac)'
> 
> But the manual page makes it clear that each case must be ended with
> ";;".
> 
>        case word in [ [(] pattern [ | pattern ] ... ) list ;; ] ... esac
> 
> Now, I haven't investigated what cleverness Bash uses, but all the cases
> I've tested that conform to the case syntax are handled correctly inside
> this $(...):
> 
> $ bash -c ': $( case x in x) : ;; esac )'
> $ bash -c ': $( case x in x) true ;; esac )'
> $ bash -c ': $( case x in (x) true ;; esac )'
> 
> It even works with the degenerate case where there are no coices, though
> writing it is hard because "esac" is a keyword:
> 
> $ bash -c ': $( case x in 
> more> esac )'
> 
> This is with an old version, 4.2.53(1).

$ bash -c ': $( case x in x)
esac ); echo $?'
0


Doesn't seem like a special power of your degenerate case. Just a
running trend that esac does not get recognized without a separator.

-- 
Eli Schwartz
Arch Linux Bug Wrangler and Trusted User

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