Re: Unclosed quotes on heredoc mode

[Chet Ramey]

On 11/20/21 12:35 PM, Robert Elz wrote:
>      Date:        Sat, 20 Nov 2021 11:33:37 -0500
>      From:        Chet Ramey <chet.ramey@case.edu>
>      Message-ID:  <4addb789-50b6-12a5-7b8a-8a082abaa50d@case.edu>
>
>    | I'm skeptical, but willing to be convinced. Bourne's shell allowed EOF to
>    | terminate all sorts of things (quoted strings, command substitutions, here
>    | documents) -- enough to make it purposeful.
>
> More likely economical.   Making things fit in that sh was a real challenge.

Right. Purposeful.

> That's a good starting point, provided you're willing to actually implement
> that.  That's what I'd like. 

How about this. You show me examples where bash (devel bash) does what you
think is the wrong thing, and we agree it's a bug, I'll fix it.

>  But for this you need to understand that
> the shell has to parse and understand command substitutions, as they're read,
> in order to correctly find the end,

The devel bash already does this. We've talked about it before. You need to
use bison, not byacc, and a new enough version of bison, but it works fine.

> and a newline token in the middle of
> a command substitution counts for a here doc operator that occurred before
> it, 

What does `counts' mean? You're not really reading the lines as shell
words, so a command substitution isn't really a command substitution while
you're reading the body of a here-document. You mean something like this?

cat << EOF
echo $(echo this EOF is
not the end of
the command substitution
EOF
but it is the end of the
here-document
)


> and a here doc operator in a command substitution might not encounter
> a newline until after the cmdsub text has ended - the next following newline
> token provides there here doc text.

I can't imagine a useful example of this that isn't an error.

Chet
--
``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/