Re: Potential ksh bug?

On 17.11.2020 05:04, Jordan Geoghegan wrote:
> Hello,
>
> I'm not sure if this is a bug, or if it's just a pdksh thing, but I
> stumbled upon some interesting behaviour when I was tinkering around
> with quoting and using a poor mans array:
>
> test=$(cat <<'__EOT'
> # I'll choose not to close this quote
> other_stuff
> __EOT
> )
>
> echo "$test"
>
>
> When I run this command on ash, dash, yash, bash, zsh or ksh93 I get
> the following output:
>
> # I'll choose not to close this quote
> other_stuff
>
> But when I run it on ksh from base or any pdksh derivative it throws
> an error about an unclosed quote:
>
> test.sh[8]: no closing quote
>
> This snippet works on every POSIX-y shell in the ports tree, and fails
> on every pdksh variant I tried, including on NetBSD and DragonflyBSD
> as well.  I don't have the requisite esoteric knowledge regarding
> pdksh's internal quoting logic, so I'm hoping one of the gurus here
> can determine whether this is a bug or if I'm just doing something
> annoying.
>
> Any insight that can be provided would be much appreciated.
>

What exactly are you trying to achieve?

If you will look in sh(1) for 'Command expansion' then there are defined
rules and your form is not between them.

So error message about missing closing quote is actually proper
behavior.

Plus I will not be so sure that bash is behaving properly:

$ bash -x test.sh
++ cat
+ test='
# I'\''ll choose not to close this quote
other_stuff'
+ echo '#' 'I'\''ll' choose not to close this quote other_stuff
# I'll choose not to close this quote other_stuff
$

Notice how one single quote is here "test='" abd second one is in
"other_stuff'"

You can compare results between various shells with ktrace/ktruss too

$ bash --version | head -1
GNU bash, version 5.0.18(1)-release (x86_64-unknown-openbsd6.8)
$

If you want to read the file then you do not need interaction and if
you want to get input from user then use 'read'

As well it is good idea to avoid reserved words as a names for variables
;-)
(test............)

> Regards,
>
> Jordan