Re: Incorrect alias expansion within command substitution

[Chet Ramey]

On 2/3/22 9:46 PM, Alex fxmbsw7 Ratchev wrote:

>     The case I had in question with the question about $( a b ) was this
>     one...
>
>              cat <<$( a b )
>              hello
>              $( a b )
>
>
> i think you are mis understanding the differencies here between shell 
> expression parsing, and a rather data only part which applies here
> that is, <<{word} is a word and is threated as flat text word, in further 
> eof recognition, applying advanced expressions here seems me like an early bug

It is a WORD (in the POSIX grammar sense), and so recursive parsing and
alias expansion are required as soon as you hit the `$('. It's what you
do with the word once you have it that matters.

> imho the example above should have resulted in error ')'
> it would execute cat a b ) with hello till $( then rather \n and a b ) 
> again, useless
> especially the $( wasnt even quoted

What can this possibly mean? What semantic interpretation would lead you
to the conclusion that you should stop reading the token after a `$(' in
this one specific case?

> chet didnt you say there were no bugs ? =)

I didn't, but how is that relevant here?

--
``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/