Re: [Help-bash] Backquote form of command substitution within double quotes

[Stephane Chazelas]

2015-06-22 15:15:32 -0700, Michael Convey:
[...]
> Is the first undefined case described by the following?
> command "`command "argu`"ment"
> 
> Is the second undefined case described by the following?
> command "`command" argument`
> 
> I'm not sure I understand these undefined cases (especially the 2nd one).
> Thoughts?

For portability with ksh or the Bourne shell, you need:

echo "`echo \"foo  bar\"` baz"'

$ ksh -c 'echo "`echo "foo  bar"` baz"'
ksh: baz: not found [No such file or directory]
foo bar

The above is treated as:

echo "$(echo )"foo  bar"$( baz)"

If you have to use `...`, my advise would be to use intermediary
variables, not quote the command substitutions (in those
variable assignments) and not nest them:

var=`echo "foo  bar"`
echo "$var baz"

-- 
Stephane