On 11/16/20 10:36 PM, Bodie wrote:
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
I'm not trying to achieve anything in particular, I was just testing out
differences in behaviour between different shells. I just noticed that
pdksh variants handled this differently than any other shell I tested in
the ports tree.
Regards,
Jordan
