Re: why fail , [[ $sep$*$sep == $sep--$sep ]]

[Chet Ramey]

On 2/18/24 3:56 PM, Lawrence Velázquez wrote:

> This surprises me because IFS is not lost if it's set to something
> a little less ... weird:
>
> $ (set aa bb cc -- dd; f=+ IFS=$f; set -x; [[ $f$*$f == *"$f--$f"* ]])
> + [[ +aa+bb+cc+--+dd+ == *\+\-\-\+* ]]
>
> Why the difference?

Bash uses ^A internally as a temporary quoting character. As a result, it
needs to be careful about quoting ^A when it's in the result of a word
expansion. It's not just IFS; it matters here because $* separates the
positional parameter with the first character of $IFS.

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/